Viewing archive of Thursday, 8 April 1999
Solar activity report
Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 1999 Apr 08 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 098 Issued at 2200Z on 08 APR 1999IA. Analysis of Solar Active Regions and Activity from 07-2100Z to 08-2100Z
SOLAR ACTIVITY WAS MODERATE. REGION 8508 (N22E13)
PRODUCED AN IMPULSIVE M1/SF AT 08/1613Z. THIS EVENT WAS PRECEDED BY
MANY PLAGE FLUCTUATIONS AND SEVERAL SMALL TO MID C-CLASS FLARES FROM
THIS REGION. DURING THE LAST 24 HOURS, REGION 8508 MAINTAINED ITS
MIXED POLARITIES AND GREW AT A MODERATE PACE. A SMALL REGION EMERGED
NEAR S27E53 AND WAS NUMBERED AS REGION 8512.
IB. Solar Activity Forecast
SOLAR ACTIVITY SHOULD BE LOW TO
MODERATE FOR THE NEXT THREE DAYS. REGION 8508 MAY BE ENTERING A
PHASE OF RE-GROWTH AND THE FREQUENCY OF M-CLASS EVENTS MAY INCREASE.
X-CLASS FLARES ARE NOT EXPECTED AT THIS TIME BUT CONTINUED GROWTH IN
REGION 8508 WOULD CHANGE THAT FORECAST.
IIA. Geophysical Activity Summary 07-2100Z to 08-2100Z
THE GEOMAGNETIC FIELD BEGAN THE PERIOD AT QUIET LEVELS. ACTIVE
CONDITIONS WERE OBSERVED DURING THE 08/1500-1800Z PERIOD. UNSETTLED
CONDITIONS OCCURRED AT THE END OF THE PERIOD. NO SHOCK WAS OBSERVED
IN THE NEARLY CONTINUOUS SOLAR WIND RECORD AND VELOCITY WAS
RELATIVELY LOW BETWEEN 350-400 KM/S. ENERGETIC ELECTRON FLUXES AT
GEOSYNCHRONOUS ORBIT REACHED HIGH LEVELS DURING THE PERIOD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD SHOULD BE
PREDOMINANTLY QUIET TO UNSETTLED FOR THE NEXT THREE DAYS. ISOLATED
ACTIVE INTERVALS ARE POSSIBLE ON 09 APR.
III. Event Probabilities 09 APR to 11 APR
| Class M | 50% | 50% | 50% |
| Class X | 10% | 10% | 10% |
| Proton | 10% | 10% | 10% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 08 APR 139 Predicted 09 APR-11 APR 140/139/135 90 Day Mean 08 APR 134
V. Geomagnetic A Indices
OBSERVED AFR/AP 07 APR 010/009 ESTIMATED AFR/AP 08 APR 010/012 PREDICTED AFR/AP 09 APR-11 APR 010/010-010/010-008/008
VI. Geomagnetic Activity Probabilities 09 APR to 11 APR
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 25% | 15% | 15% |
| Minor storm | 15% | 05% | 05% |
| Major-severe storm | 05% | 01% | 05% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 25% | 15% | 15% |
| Minor storm | 15% | 05% | 05% |
| Major-severe storm | 05% | 01% | 05% |
All times in UTC
Latest news
Wednesday, 14 May 2025
Another X-flare! Potent sunspot region 4087!
Tuesday, 13 May 2025
X1.1 solar flare from sunspot region 4086
Tuesday, 15 April 2025
CME arrival, G3 storm watch
Latest forum messages
AR4087 203Incoming & Unnumbered Active Regions 1902Line chart of indicators on the auror video, animated graph trace 44Filaments and prominences 168New around here. Carrington and Miyake 10
More topicsSupport SpaceWeatherLive.com!
A lot of people come to SpaceWeatherLive to follow the Sun's activity or if there is aurora to be seen, but with more traffic comes higher server costs. Consider a donation if you enjoy SpaceWeatherLive so we can keep the website online!
Space weather facts
| Last X-flare | 2025/05/14 | X2.7 |
| Last M-flare | 2025/05/19 | M3.1 |
| Last geomagnetic storm | 2025/05/17 | Kp6+ (G2) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| April 2025 | 140.6 +6.4 |
| May 2025 | 68.9 -71.7 |
| Last 30 days | 92.7 -23.7 |