Viewing archive of Sunday, 11 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 11 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 101 Issued at 2200Z on 11 APR 1999IA. Analysis of Solar Active Regions and Activity from 10-2100Z to 11-2100Z SOLAR ACTIVITY HAS BEEN LOW WITH MINOR FLARES UP TO
CLASS C INTENSITY OCCURRING IN REGION 8508 (N22W29). THE REGION
APPEARS TO BE SLOWLY DISSIPATING BUT REMAINS ACTIVE AND COMPLEX.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW.
IIA. Geophysical Activity Summary 10-2100Z to 11-2100Z
THE GEOMAGNETIC FIELD HAS BEEN UNSETTLED. THE SOURCE OF THE SMALL
ENHANCEMENT OF ACTIVITY APPEARED TO BE A MODERATE HIGH-SPEED STREAM
IN THE SOLAR WIND. CURRENT OBSERVATIONS INDICATE A SLOW DECAY
TOWARD MORE NOMINAL VALUES. ENERGETIC ELECTRONS AT GEOSYNCHRONOUS
ORBIT REMAIN MODERATELY ENHANCED.
IIB. Geophysical Activity Forecast
GEOMAGNETIC ACTIVITY IS
EXPECTED TO BE QUIET TO UNSETTLED.
III. Event Probabilities 12 APR to 14 APR
| Class M | 25% | 25% | 25% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 11 APR 131 Predicted 12 APR-14 APR 130/130/128 90 Day Mean 11 APR 135
V. Geomagnetic A Indices
OBSERVED AFR/AP 10 APR 009/011 ESTIMATED AFR/AP 11 APR 012/010 PREDICTED AFR/AP 12 APR-14 APR 010/010-010/008-009/007
VI. Geomagnetic Activity Probabilities 12 APR to 14 APR
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 13% | 14% | 15% |
| Minor storm | 07% | 05% | 06% |
| Major-severe storm | 03% | 03% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 15% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 05% | 05% | 05% |
All times in UTC
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