NOAA SWPC Alerts, Watches and Warnings

The National Oceanic and Atmospheric Administration Space Weather Prediction Center (NOAA SWPC) is the official space weather government agency from the United States that provides alerts, watches and warning for space weather disturbances. Below you will find the latest space weather alerts, watches and warnings issued by the NOAA SWPC.

Friday, 23 May 2025

09:14 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3469
Issue Time: 2025 May 23 0914 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3468
Begin Time: 2025 May 22 1240 UTC
Yesterday Maximum 2MeV Flux: 1643 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Thursday, 22 May 2025

12:56 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3468
Issue Time: 2025 May 22 1256 UTC

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2025 May 22 1240 UTC
Station: GOES19




Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Wednesday, 21 May 2025

01:40 UTC

Space Weather Message Code: ALTK04
Serial Number: 2561
Issue Time: 2025 May 21 0140 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 May 21 0140 UTC
Synoptic Period: 0000-0300 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

01:38 UTC

Space Weather Message Code: WARK04
Serial Number: 4972
Issue Time: 2025 May 21 0138 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 21 0138 UTC
Valid To: 2025 May 21 1200 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Tuesday, 20 May 2025

22:55 UTC

Space Weather Message Code: SUM10R
Serial Number: 866
Issue Time: 2025 May 20 2255 UTC

SUMMARY: 10cm Radio Burst
Begin Time: 2025 May 20 2239 UTC
Maximum Time: 2025 May 20 2239 UTC
End Time: 2025 May 20 2243 UTC
Duration: 4 minutes
Peak Flux: 190 sfu
Latest Penticton Noon Flux: 119 sfu



Description: A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.

14:27 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3467
Issue Time: 2025 May 20 1427 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3466
Begin Time: 2025 May 18 1705 UTC
Yesterday Maximum 2MeV Flux: 1870 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

07:11 UTC

Space Weather Message Code: WARK04
Serial Number: 4971
Issue Time: 2025 May 20 0711 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 20 0711 UTC
Valid To: 2025 May 20 1500 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Monday, 19 May 2025

18:01 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3466
Issue Time: 2025 May 19 1801 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3465
Begin Time: 2025 May 18 1705 UTC
Yesterday Maximum 2MeV Flux: 1870 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

10:13 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3465
Issue Time: 2025 May 19 1013 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3464
Begin Time: 2025 May 18 1705 UTC
Yesterday Maximum 2MeV Flux: 1155 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Sunday, 18 May 2025

23:54 UTC

Space Weather Message Code: WARK04
Serial Number: 4970
Issue Time: 2025 May 18 2354 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4969
Valid From: 2025 May 16 2255 UTC
Now Valid Until: 2025 May 19 2359 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

17:21 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3464
Issue Time: 2025 May 18 1721 UTC

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2025 May 18 1705 UTC
Station: GOES19




Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

14:55 UTC

Space Weather Message Code: WARK04
Serial Number: 4969
Issue Time: 2025 May 18 1455 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4968
Valid From: 2025 May 16 2255 UTC
Now Valid Until: 2025 May 18 2359 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

08:35 UTC

Space Weather Message Code: ALTK05
Serial Number: 1773
Issue Time: 2025 May 18 0835 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 18 0834 UTC
Synoptic Period: 0600-0900 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

Saturday, 17 May 2025

21:06 UTC

Space Weather Message Code: WARK04
Serial Number: 4968
Issue Time: 2025 May 17 2106 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4967
Valid From: 2025 May 16 2255 UTC
Now Valid Until: 2025 May 18 1500 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

20:55 UTC

Space Weather Message Code: WARK05
Serial Number: 2045
Issue Time: 2025 May 17 2055 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2044
Valid From: 2025 May 17 0050 UTC
Now Valid Until: 2025 May 18 1200 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

11:52 UTC

Space Weather Message Code: WARK06
Serial Number: 581
Issue Time: 2025 May 17 1152 UTC

EXTENDED WARNING: Geomagnetic K-Index of 6 expected
Extension to Serial Number: 580
Valid From: 2025 May 17 0052 UTC
Now Valid Until: 2025 May 17 1800 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.

11:52 UTC

Space Weather Message Code: WARK05
Serial Number: 2044
Issue Time: 2025 May 17 1152 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2043
Valid From: 2025 May 17 0050 UTC
Now Valid Until: 2025 May 17 2100 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

11:25 UTC

Space Weather Message Code: ALTK05
Serial Number: 1772
Issue Time: 2025 May 17 1125 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 17 1122 UTC
Synoptic Period: 0900-1200 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

05:07 UTC

Space Weather Message Code: ALTK05
Serial Number: 1771
Issue Time: 2025 May 17 0507 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 17 0459 UTC
Synoptic Period: 0300-0600 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

00:54 UTC

Space Weather Message Code: ALTK06
Serial Number: 629
Issue Time: 2025 May 17 0054 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2025 May 17 0054 UTC
Synoptic Period: 0000-0300 UTC

Active Warning: Yes
NOAA Scale: G2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.

00:53 UTC

Space Weather Message Code: ALTK05
Serial Number: 1770
Issue Time: 2025 May 17 0053 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 17 0052 UTC
Synoptic Period: 0000-0300 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

00:52 UTC

Space Weather Message Code: WARK06
Serial Number: 580
Issue Time: 2025 May 17 0052 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2025 May 17 0052 UTC
Valid To: 2025 May 17 1200 UTC
Warning Condition: Onset
NOAA Scale: G2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.

00:51 UTC

Space Weather Message Code: WARK05
Serial Number: 2043
Issue Time: 2025 May 17 0051 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 May 17 0050 UTC
Valid To: 2025 May 17 1500 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

Friday, 16 May 2025

23:36 UTC

Space Weather Message Code: ALTK04
Serial Number: 2560
Issue Time: 2025 May 16 2336 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 May 16 2331 UTC
Synoptic Period: 2100-2400 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

22:56 UTC

Space Weather Message Code: WARK04
Serial Number: 4967
Issue Time: 2025 May 16 2256 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 16 2255 UTC
Valid To: 2025 May 17 2359 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

19:00 UTC

Space Weather Message Code: WATA20
Serial Number: 1041
Issue Time: 2025 May 16 1900 UTC

WATCH: Geomagnetic Storm Category G1 Predicted

Highest Storm Level Predicted by Day:
May 17: None (Below G1) May 18: G1 (Minor) May 19: G1 (Minor)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

Comment: Coronal Hole High Speed Stream influences will likely lead to G1 storm potential 18-19 May.

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

07:42 UTC

Space Weather Message Code: WARK04
Serial Number: 4966
Issue Time: 2025 May 16 0742 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 16 0742 UTC
Valid To: 2025 May 16 1200 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Thursday, 15 May 2025

22:52 UTC

Space Weather Message Code: WATA20
Serial Number: 1040
Issue Time: 2025 May 15 2252 UTC

WATCH: Geomagnetic Storm Category G1 Predicted

Highest Storm Level Predicted by Day:
May 16: None (Below G1) May 17: None (Below G1) May 18: G1 (Minor)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

05:09 UTC

Space Weather Message Code: WARK05
Serial Number: 2042
Issue Time: 2025 May 15 0509 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 May 15 0508 UTC
Valid To: 2025 May 15 1200 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

05:09 UTC

Space Weather Message Code: WARK04
Serial Number: 4965
Issue Time: 2025 May 15 0509 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4964
Valid From: 2025 May 15 0332 UTC
Now Valid Until: 2025 May 15 1500 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

03:49 UTC

Space Weather Message Code: ALTK04
Serial Number: 2559
Issue Time: 2025 May 15 0349 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 May 15 0345 UTC
Synoptic Period: 0300-0600 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

03:33 UTC

Space Weather Message Code: WARK04
Serial Number: 4964
Issue Time: 2025 May 15 0333 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 15 0332 UTC
Valid To: 2025 May 15 0900 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Wednesday, 14 May 2025

18:03 UTC

Space Weather Message Code: ALTK04
Serial Number: 2558
Issue Time: 2025 May 14 1803 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 May 14 1755 UTC
Synoptic Period: 1500-1800 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

18:03 UTC

Space Weather Message Code: WARK04
Serial Number: 4963
Issue Time: 2025 May 14 1803 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 14 1730 UTC
Valid To: 2025 May 15 0000 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

11:36 UTC

Space Weather Message Code: SUMXM5
Serial Number: 289
Issue Time: 2025 May 14 1136 UTC

SUMMARY: X-ray Event exceeded M5
Begin Time: 2025 May 14 1104 UTC
Maximum Time: 2025 May 14 1119 UTC
End Time: 2025 May 14 1131 UTC
X-ray Class: M7
Optical Class: na
Location: N15E58
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes.

11:17 UTC

Space Weather Message Code: ALTXMF
Serial Number: 482
Issue Time: 2025 May 14 1117 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2025 May 14 1115 UTC
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

08:39 UTC

Space Weather Message Code: SUMX01
Serial Number: 193
Issue Time: 2025 May 14 0839 UTC

SUMMARY: X-ray Event exceeded X1
Begin Time: 2025 May 14 0804 UTC
Maximum Time: 2025 May 14 0825 UTC
End Time: 2025 May 14 0831 UTC
X-ray Class: X2.7
Optical Class: 2b
Location: N15E60
NOAA Scale: R3 - Strong

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact consists of large portions of the sunlit side of Earth, strongest at the sub-solar point.
Radio - Wide area blackout of HF (high frequency) radio communication for about an hour.

08:30 UTC

Space Weather Message Code: SUM10R
Serial Number: 865
Issue Time: 2025 May 14 0830 UTC

SUMMARY: 10cm Radio Burst
Begin Time: 2025 May 14 0817 UTC
Maximum Time: 2025 May 14 0818 UTC
End Time: 2025 May 14 0818 UTC
Duration: 1 minutes
Peak Flux: 390 sfu
Latest Penticton Noon Flux: 117 sfu



Description: A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.

08:19 UTC

Space Weather Message Code: ALTXMF
Serial Number: 481
Issue Time: 2025 May 14 0819 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2025 May 14 0817 UTC
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

04:20 UTC

Space Weather Message Code: ALTTP2
Serial Number: 1413
Issue Time: 2025 May 14 0420 UTC

ALERT: Type II Radio Emission
Begin Time: 2025 May 14 0323 UTC
Estimated Velocity: 238 km/s



Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.

03:45 UTC

Space Weather Message Code: SUMXM5
Serial Number: 288
Issue Time: 2025 May 14 0345 UTC

SUMMARY: X-ray Event exceeded M5
Begin Time: 2025 May 14 0305 UTC
Maximum Time: 2025 May 14 0325 UTC
End Time: 2025 May 14 0335 UTC
X-ray Class: M5.3
Location: N17E65
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes.

03:25 UTC

Space Weather Message Code: ALTXMF
Serial Number: 480
Issue Time: 2025 May 14 0325 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2025 May 14 0323 UTC
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

00:57 UTC

Space Weather Message Code: WARK04
Serial Number: 4962
Issue Time: 2025 May 14 0057 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 14 0058 UTC
Valid To: 2025 May 14 1200 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Tuesday, 13 May 2025

18:52 UTC

Space Weather Message Code: WARPX1
Serial Number: 601
Issue Time: 2025 May 13 1852 UTC

WARNING: Proton 10MeV Integral Flux above 10pfu expected
Valid From: 2025 May 13 1930 UTC
Valid To: 2025 May 14 1200 UTC
Warning Condition: Onset
Predicted NOAA Scale: S1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Radio - Minor impacts on polar HF (high frequency) radio propagation resulting in fades at lower frequencies.

16:13 UTC

Space Weather Message Code: SUM10R
Serial Number: 864
Issue Time: 2025 May 13 1613 UTC

SUMMARY: 10cm Radio Burst
Begin Time: 2025 May 13 1534 UTC
Maximum Time: 2025 May 13 1534 UTC
End Time: 2025 May 13 1535 UTC
Duration: 1 minutes
Peak Flux: 220 sfu
Latest Penticton Noon Flux: 116 sfu



Description: A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.

16:07 UTC

Space Weather Message Code: ALTTP2
Serial Number: 1412
Issue Time: 2025 May 13 1607 UTC

ALERT: Type II Radio Emission
Begin Time: 2025 May 13 1542 UTC
Estimated Velocity: 658 km/s



Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.

15:52 UTC

Space Weather Message Code: SUMX01
Serial Number: 192
Issue Time: 2025 May 13 1552 UTC

SUMMARY: X-ray Event exceeded X1
Begin Time: 2025 May 13 1525 UTC
Maximum Time: 2025 May 13 1538 UTC
End Time: 2025 May 13 1544 UTC
X-ray Class: X1.2
Optical Class: 1b
Location: N08W90
NOAA Scale: R3 - Strong

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact consists of large portions of the sunlit side of Earth, strongest at the sub-solar point.
Radio - Wide area blackout of HF (high frequency) radio communication for about an hour.

15:37 UTC

Space Weather Message Code: ALTXMF
Serial Number: 479
Issue Time: 2025 May 13 1537 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2025 May 13 1535 UTC
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

Sunday, 11 May 2025

21:02 UTC

Space Weather Message Code: WARK05
Serial Number: 2041
Issue Time: 2025 May 11 2102 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 May 11 2100 UTC
Valid To: 2025 May 12 0600 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

21:00 UTC

Space Weather Message Code: ALTK05
Serial Number: 1769
Issue Time: 2025 May 11 2100 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 11 2058 UTC
Synoptic Period: 1800-2100 UTC

Active Warning: No
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

20:24 UTC

Space Weather Message Code: ALTK04
Serial Number: 2557
Issue Time: 2025 May 11 2024 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 May 11 2021 UTC
Synoptic Period: 1800-2100 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

14:55 UTC

Space Weather Message Code: WARK04
Serial Number: 4961
Issue Time: 2025 May 11 1455 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4960
Valid From: 2025 May 11 0420 UTC
Now Valid Until: 2025 May 12 1800 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

04:20 UTC

Space Weather Message Code: WARK04
Serial Number: 4960
Issue Time: 2025 May 11 0420 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 11 0420 UTC
Valid To: 2025 May 11 1500 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Saturday, 10 May 2025

10:26 UTC

Space Weather Message Code: WARK05
Serial Number: 2040
Issue Time: 2025 May 10 1026 UTC

CANCEL WARNING: Geomagnetic K-index of 5 expected
Cancel Serial Number: 2039
Original Issue Time: 2025 May 09 2348 UTC

Comment: Geomagnetic K-index of 5 no longer expected.

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

06:06 UTC

Space Weather Message Code: WARK04
Serial Number: 4959
Issue Time: 2025 May 10 0606 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4958
Valid From: 2025 May 09 1953 UTC
Now Valid Until: 2025 May 10 1800 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

05:59 UTC

Space Weather Message Code: WARK05
Serial Number: 2039
Issue Time: 2025 May 10 0559 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2038
Valid From: 2025 May 09 2348 UTC
Now Valid Until: 2025 May 10 1200 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

Friday, 9 May 2025

23:48 UTC

Space Weather Message Code: WARK05
Serial Number: 2038
Issue Time: 2025 May 09 2348 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 May 09 2348 UTC
Valid To: 2025 May 10 0600 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

19:57 UTC

Space Weather Message Code: ALTK04
Serial Number: 2556
Issue Time: 2025 May 09 1957 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 May 09 1956 UTC
Synoptic Period: 1800-2100 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

19:56 UTC

Space Weather Message Code: WARK04
Serial Number: 4958
Issue Time: 2025 May 09 1956 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 09 1953 UTC
Valid To: 2025 May 10 1200 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

06:42 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3463
Issue Time: 2025 May 09 0642 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3462
Begin Time: 2025 May 02 1330 UTC
Yesterday Maximum 2MeV Flux: 15854 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Thursday, 8 May 2025

22:34 UTC

Space Weather Message Code: ALTK04
Serial Number: 2555
Issue Time: 2025 May 08 2234 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 May 08 2234 UTC
Synoptic Period: 2100-2400 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

22:24 UTC

Space Weather Message Code: WARK04
Serial Number: 4957
Issue Time: 2025 May 08 2224 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 08 2224 UTC
Valid To: 2025 May 09 0600 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

04:59 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3462
Issue Time: 2025 May 08 0459 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3461
Begin Time: 2025 May 02 1330 UTC
Yesterday Maximum 2MeV Flux: 12994 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Wednesday, 7 May 2025

11:47 UTC

Space Weather Message Code: WATA20
Serial Number: 1039
Issue Time: 2025 May 07 1147 UTC

WATCH: Geomagnetic Storm Category G1 Predicted

Highest Storm Level Predicted by Day:
May 07: None (Below G1) May 08: None (Below G1) May 09: G1 (Minor)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

04:59 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3461
Issue Time: 2025 May 07 0459 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3460
Begin Time: 2025 May 02 1330 UTC
Yesterday Maximum 2MeV Flux: 11876 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Tuesday, 6 May 2025

23:46 UTC

Space Weather Message Code: WARK04
Serial Number: 4956
Issue Time: 2025 May 06 2346 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4955
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 07 1200 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

14:52 UTC

Space Weather Message Code: WARK04
Serial Number: 4955
Issue Time: 2025 May 06 1452 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4954
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 06 2359 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

08:55 UTC

Space Weather Message Code: WARK04
Serial Number: 4954
Issue Time: 2025 May 06 0855 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4953
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 06 1500 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

05:00 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3460
Issue Time: 2025 May 06 0500 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3459
Begin Time: 2025 May 02 1330 UTC
Yesterday Maximum 2MeV Flux: 16255 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Monday, 5 May 2025

23:48 UTC

Space Weather Message Code: WARK05
Serial Number: 2037
Issue Time: 2025 May 05 2348 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2036
Valid From: 2025 May 04 2010 UTC
Now Valid Until: 2025 May 06 0900 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

18:06 UTC

Space Weather Message Code: WATA20
Serial Number: 1038
Issue Time: 2025 May 05 1806 UTC

WATCH: Geomagnetic Storm Category G1 Predicted

Highest Storm Level Predicted by Day:
May 06: G1 (Minor) May 07: None (Below G1) May 08: None (Below G1)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

18:03 UTC

Space Weather Message Code: ALTK05
Serial Number: 1768
Issue Time: 2025 May 05 1803 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 05 1759 UTC
Synoptic Period: 1500-1800 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

14:38 UTC

Space Weather Message Code: WARK05
Serial Number: 2036
Issue Time: 2025 May 05 1438 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2035
Valid From: 2025 May 04 2010 UTC
Now Valid Until: 2025 May 05 2359 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

14:30 UTC

Space Weather Message Code: WARK04
Serial Number: 4953
Issue Time: 2025 May 05 1430 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4952
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 06 0900 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

06:00 UTC

Space Weather Message Code: ALTK05
Serial Number: 1767
Issue Time: 2025 May 05 0600 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 05 0559 UTC
Synoptic Period: 0300-0600 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

05:55 UTC

Space Weather Message Code: WARK04
Serial Number: 4952
Issue Time: 2025 May 05 0555 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4951
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 05 2100 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

05:55 UTC

Space Weather Message Code: WARK05
Serial Number: 2035
Issue Time: 2025 May 05 0555 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2034
Valid From: 2025 May 04 2010 UTC
Now Valid Until: 2025 May 05 1500 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

05:00 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3459
Issue Time: 2025 May 05 0500 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3458
Begin Time: 2025 May 02 1330 UTC
Yesterday Maximum 2MeV Flux: 9364 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Sunday, 4 May 2025

20:11 UTC

Space Weather Message Code: WARK05
Serial Number: 2034
Issue Time: 2025 May 04 2011 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 May 04 2010 UTC
Valid To: 2025 May 05 0600 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

18:58 UTC

Space Weather Message Code: WARK04
Serial Number: 4951
Issue Time: 2025 May 04 1858 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4950
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 05 1200 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

07:53 UTC

Space Weather Message Code: ALTK05
Serial Number: 1766
Issue Time: 2025 May 04 0753 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 04 0752 UTC
Synoptic Period: 0600-0900 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

07:23 UTC

Space Weather Message Code: WARK04
Serial Number: 4950
Issue Time: 2025 May 04 0723 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4949
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 04 2100 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

07:23 UTC

Space Weather Message Code: WARK05
Serial Number: 2033
Issue Time: 2025 May 04 0723 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 May 04 0722 UTC
Valid To: 2025 May 04 1500 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

05:31 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3458
Issue Time: 2025 May 04 0531 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3457
Begin Time: 2025 May 02 1330 UTC
Yesterday Maximum 2MeV Flux: 5464 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Saturday, 3 May 2025

17:27 UTC

Space Weather Message Code: WARK04
Serial Number: 4949
Issue Time: 2025 May 03 1727 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4948
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 04 1200 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

11:49 UTC

Space Weather Message Code: WARK05
Serial Number: 2032
Issue Time: 2025 May 03 1149 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2031
Valid From: 2025 May 01 1350 UTC
Now Valid Until: 2025 May 03 1800 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

10:32 UTC

Space Weather Message Code: ALTK05
Serial Number: 1765
Issue Time: 2025 May 03 1032 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 03 1030 UTC
Synoptic Period: 0900-1200 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

06:51 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3457
Issue Time: 2025 May 03 0651 UTC

CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Continuation of Serial Number: 3456
Begin Time: 2025 May 02 1330 UTC
Yesterday Maximum 2MeV Flux: 1451 pfu



Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

01:29 UTC

Space Weather Message Code: WARK06
Serial Number: 579
Issue Time: 2025 May 03 0129 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2025 May 03 0130 UTC
Valid To: 2025 May 03 0900 UTC
Warning Condition: Onset
NOAA Scale: G2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.

01:29 UTC

Space Weather Message Code: WARK05
Serial Number: 2031
Issue Time: 2025 May 03 0129 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2030
Valid From: 2025 May 01 1350 UTC
Now Valid Until: 2025 May 03 1200 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

01:29 UTC

Space Weather Message Code: WARK04
Serial Number: 4948
Issue Time: 2025 May 03 0129 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4947
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 03 1800 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

00:56 UTC

Space Weather Message Code: ALTK05
Serial Number: 1764
Issue Time: 2025 May 03 0056 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 03 0055 UTC
Synoptic Period: 0000-0300 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

Friday, 2 May 2025

23:25 UTC

Space Weather Message Code: ALTK05
Serial Number: 1763
Issue Time: 2025 May 02 2325 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 02 2320 UTC
Synoptic Period: 2100-2400 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

18:02 UTC

Space Weather Message Code: ALTK05
Serial Number: 1762
Issue Time: 2025 May 02 1802 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 02 1759 UTC
Synoptic Period: 1500-1800 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

17:46 UTC

Space Weather Message Code: WARK04
Serial Number: 4947
Issue Time: 2025 May 02 1746 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4946
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 03 1200 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

17:41 UTC

Space Weather Message Code: WARK05
Serial Number: 2030
Issue Time: 2025 May 02 1741 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2029
Valid From: 2025 May 01 1350 UTC
Now Valid Until: 2025 May 03 0600 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

14:40 UTC

Space Weather Message Code: ALTK05
Serial Number: 1761
Issue Time: 2025 May 02 1440 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 02 1435 UTC
Synoptic Period: 1200-1500 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

13:44 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3456
Issue Time: 2025 May 02 1344 UTC

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2025 May 02 1330 UTC
Station: GOES19




Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

08:31 UTC

Space Weather Message Code: WARK05
Serial Number: 2029
Issue Time: 2025 May 02 0831 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2028
Valid From: 2025 May 01 1350 UTC
Now Valid Until: 2025 May 02 1800 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

08:30 UTC

Space Weather Message Code: WARK04
Serial Number: 4946
Issue Time: 2025 May 02 0830 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4945
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 02 2100 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

05:07 UTC

Space Weather Message Code: ALTK05
Serial Number: 1760
Issue Time: 2025 May 02 0507 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 02 0459 UTC
Synoptic Period: 0300-0600 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

02:06 UTC

Space Weather Message Code: WARK06
Serial Number: 578
Issue Time: 2025 May 02 0206 UTC

WARNING: Geomagnetic K-Index of 6 expected
Valid From: 2025 May 02 0206 UTC
Valid To: 2025 May 02 0900 UTC
Warning Condition: Onset
NOAA Scale: G2 - Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio - HF (high frequency) radio propagation can fade at higher latitudes.
Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.

01:55 UTC

Space Weather Message Code: ALTK05
Serial Number: 1759
Issue Time: 2025 May 02 0155 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 02 0155 UTC
Synoptic Period: 0000-0300 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

Thursday, 1 May 2025

23:53 UTC

Space Weather Message Code: WARK04
Serial Number: 4945
Issue Time: 2025 May 01 2353 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4944
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 02 1500 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

23:48 UTC

Space Weather Message Code: WARK05
Serial Number: 2028
Issue Time: 2025 May 01 2348 UTC

EXTENDED WARNING: Geomagnetic K-index of 5 expected
Extension to Serial Number: 2027
Valid From: 2025 May 01 1350 UTC
Now Valid Until: 2025 May 02 0900 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

23:40 UTC

Space Weather Message Code: ALTK05
Serial Number: 1758
Issue Time: 2025 May 01 2340 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 01 2339 UTC
Synoptic Period: 2100-2400 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

20:23 UTC

Space Weather Message Code: ALTK05
Serial Number: 1757
Issue Time: 2025 May 01 2023 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2025 May 01 2022 UTC
Synoptic Period: 1800-2100 UTC

Active Warning: Yes
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

17:50 UTC

Space Weather Message Code: WATA20
Serial Number: 1037
Issue Time: 2025 May 01 1750 UTC

WATCH: Geomagnetic Storm Category G1 Predicted

Highest Storm Level Predicted by Day:
May 02: G1 (Minor) May 03: None (Below G1) May 04: None (Below G1)

THIS SUPERSEDES ANY/ALL PRIOR WATCHES IN EFFECT

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

13:52 UTC

Space Weather Message Code: WARK04
Serial Number: 4944
Issue Time: 2025 May 01 1352 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4943
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 02 0600 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

13:52 UTC

Space Weather Message Code: WARK05
Serial Number: 2027
Issue Time: 2025 May 01 1352 UTC

WARNING: Geomagnetic K-index of 5 expected
Valid From: 2025 May 01 1350 UTC
Valid To: 2025 May 01 2359 UTC
Warning Condition: Onset
NOAA Scale: G1 - Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Spacecraft - Minor impact on satellite operations possible.
Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

10:40 UTC

Space Weather Message Code: WARK04
Serial Number: 4943
Issue Time: 2025 May 01 1040 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4942
Valid From: 2025 May 01 0343 UTC
Now Valid Until: 2025 May 01 1800 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

05:38 UTC

Space Weather Message Code: ALTK04
Serial Number: 2554
Issue Time: 2025 May 01 0538 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 May 01 0532 UTC
Synoptic Period: 0300-0600 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

03:43 UTC

Space Weather Message Code: WARK04
Serial Number: 4942
Issue Time: 2025 May 01 0343 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 May 01 0343 UTC
Valid To: 2025 May 01 1200 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Wednesday, 30 April 2025

11:30 UTC

Space Weather Message Code: WARK04
Serial Number: 4941
Issue Time: 2025 Apr 30 1130 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4940
Valid From: 2025 Apr 30 0225 UTC
Now Valid Until: 2025 Apr 30 1500 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

03:00 UTC

Space Weather Message Code: ALTK04
Serial Number: 2553
Issue Time: 2025 Apr 30 0300 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 Apr 30 0259 UTC
Synoptic Period: 0000-0300 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

02:25 UTC

Space Weather Message Code: WARK04
Serial Number: 4940
Issue Time: 2025 Apr 30 0225 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 Apr 30 0225 UTC
Valid To: 2025 Apr 30 1200 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

Sunday, 27 April 2025

16:32 UTC

Space Weather Message Code: ALTEF3
Serial Number: 3455
Issue Time: 2025 Apr 27 1632 UTC

ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2025 Apr 27 1605 UTC
Station: GOES-19




Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.

Thursday, 24 April 2025

17:16 UTC

Space Weather Message Code: WARK04
Serial Number: 4939
Issue Time: 2025 Apr 24 1716 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4938
Valid From: 2025 Apr 24 0655 UTC
Now Valid Until: 2025 Apr 25 0900 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

11:36 UTC

Space Weather Message Code: WARK04
Serial Number: 4938
Issue Time: 2025 Apr 24 1136 UTC

EXTENDED WARNING: Geomagnetic K-index of 4 expected
Extension to Serial Number: 4937
Valid From: 2025 Apr 24 0655 UTC
Now Valid Until: 2025 Apr 24 1800 UTC
Warning Condition: Persistence

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

07:09 UTC

Space Weather Message Code: ALTK04
Serial Number: 2552
Issue Time: 2025 Apr 24 0709 UTC

ALERT: Geomagnetic K-index of 4
Threshold Reached: 2025 Apr 24 0703 UTC
Synoptic Period: 0600-0900 UTC

Active Warning: Yes

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.

06:56 UTC

Space Weather Message Code: WARK04
Serial Number: 4937
Issue Time: 2025 Apr 24 0656 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2025 Apr 24 0655 UTC
Valid To: 2025 Apr 24 1200 UTC
Warning Condition: Onset

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude.
Induced Currents - Weak power grid fluctuations can occur.
Aurora - Aurora may be visible at high latitudes such as Canada and Alaska.