Viewing archive of Thursday, 4 February 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 Feb 04 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 035 Issued at 2200Z on 04 FEB 1999IA. Analysis of Solar Active Regions and Activity from 03-2100Z to 04-2100Z SOLAR ACTIVITY WAS LOW. A LONG-DURATION C5 EVENT
OCCURRED FROM 0624 TO 0758Z. X-RAY IMAGE DATA INDICATED THAT THE
SOURCE OF THE ENHANCED X-RAYS WAS FROM BEHIND THE NORTHWEST LIMB.
REGION 8453 (S26E19) CONTINUED TO GROW SLOWLY TODAY AND IS THE ONLY
SUNSPOT REGION CURRENTLY ON THE DISK.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO VERY LOW.
IIA. Geophysical Activity Summary 03-2100Z to 04-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. QUIET CONDITIONS
PREVAILED FROM THE START OF THE PERIOD THROUGH ABOUT 1400Z. AFTER
1400Z UNSETTLED CONDITIONS BEGAN AND CONTINUED FOR THE REMAINDER OF
THE DAY. THE SOLAR WIND VELOCITY HAS MOVED UP TO VALUES 50 PERCENT
ABOVE THE 300 KM/S VALUES OF EARLY TODAY.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE FOR TOMORROW AND TREND TO QUIET
TO UNSETTLED BY THE THIRD DAY.
III. Event Probabilities 05 FEB to 07 FEB
| Class M | 05% | 05% | 05% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 04 FEB 107 Predicted 05 FEB-07 FEB 110/115/115 90 Day Mean 04 FEB 143
V. Geomagnetic A Indices
OBSERVED AFR/AP 03 FEB 004/005 ESTIMATED AFR/AP 04 FEB 009/012 PREDICTED AFR/AP 05 FEB-07 FEB 015/010-010/008-005/008
VI. Geomagnetic Activity Probabilities 05 FEB to 07 FEB
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 22% | 18% | 06% |
| Minor storm | 17% | 17% | 03% |
| Major-severe storm | 00% | 00% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 22% | 18% | 06% |
| Minor storm | 20% | 20% | 03% |
| Major-severe storm | 04% | 04% | 02% |
All times in UTC
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