Viewing archive of Friday, 23 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 23 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 113 Issued at 2200Z on 23 APR 1999IA. Analysis of Solar Active Regions and Activity from 22-2100Z to 23-2100Z SOLAR ACTIVITY WAS VERY LOW. NO FURTHER DEVELOPMENT WAS
OBSERVED IN REGION 8518 (S14W10) WHICH HAS NOW STABILIZED AS AN
E-TYPE BETA GROUP. OCCASIONAL SURGING AND POINT BRIGHTENINGS WERE
ALSO NOTED IN THIS REGION THROUGHOUT THE PERIOD. NEW REGION 8522
(N16E63) WAS NUMBERED TODAY. REMAINING REGIONS WERE QUIET.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE VERY
LOW TO LOW. REGION 8518 APPEARS TO BE THE ONLY REGION CAPABLE OF
C-CLASS ACTIVITY.
IIA. Geophysical Activity Summary 22-2100Z to 23-2100Z
THE GEOMAGNETIC FIELD WAS QUIET
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO REMAIN QUIET
III. Event Probabilities 24 APR to 26 APR
| Class M | 05% | 05% | 05% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 23 APR 098 Predicted 24 APR-26 APR 100/100/100 90 Day Mean 23 APR 130
V. Geomagnetic A Indices
OBSERVED AFR/AP 22 APR 002/004 ESTIMATED AFR/AP 23 APR 006/007 PREDICTED AFR/AP 24 APR-26 APR 007/010-010/010-010/010
VI. Geomagnetic Activity Probabilities 24 APR to 26 APR
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 15% | 15% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 20% | 20% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
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