Viewing archive of Thursday, 13 April 2000
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 2000 Apr 13 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 104 Issued at 2200Z on 13 APR 2000IA. Analysis of Solar Active Regions and Activity from 12-2100Z to 13-2100Z
SOLAR ACTIVITY DECREASED TO LOW LEVELS. REGION 8948
(S15W49) SHOWED GRADUAL SIMPLIFICATION OF ITS MAGNETIC STRUCTURE,
BUT MAINTAINED A BETA-GAMMA CLASSIFICATION. IT PRODUCED A C-CLASS
SUBFLARE EARLY IN THE PERIOD. SLIGHT GROWTH WAS REPORTED IN REGION
8959 (S17E14). THE REMAINING REGIONS WERE STABLE INCLUDING NEWLY
NUMBERED REGIONS 8960 (N19W15), 8961 (S25E07), 8962 (N21E76), AND
8963 (N15E74).
IB. Solar Activity Forecast
ACTIVITY IS EXPECTED TO BE AT LOW TO
MODERATE LEVELS. THERE IS A FAIR CHANCE FOR AN ISOLATED M-CLASS
FLARE FROM REGION 8948.
IIA. Geophysical Activity Summary 12-2100Z to 13-2100Z
GEOMAGNETIC FIELD ACTIVITY RANGED FROM QUIET TO UNSETTLED LEVELS. THE
GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT REMAINED AT
MODERATE TO HIGH LEVELS.
IIB. Geophysical Activity Forecast
GEOMAGNETIC FIELD ACTIVITY IS
EXPECTED TO REMAIN AT QUIET TO UNSETTLED LEVELS DURING MOST OF THE
PERIOD. HOWEVER, BRIEF ACTIVE PERIODS ARE POSSIBLE ON 15 APRIL DUE
TO A SMALL, FAVORABLY POSITIONED CORONAL HOLE. THE GREATER THAN 2
MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS EXPECTED TO DECREASE TO
NORMAL TO MODERATE LEVELS EARLY IN THE PERIOD.
III. Event Probabilities 14 APR to 16 APR
| Class M | 40% | 40% | 40% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 13 APR 164 Predicted 14 APR-16 APR 165/165/160 90 Day Mean 13 APR 185
V. Geomagnetic A Indices
OBSERVED AFR/AP 12 APR 007/005 ESTIMATED AFR/AP 13 APR 005/008 PREDICTED AFR/AP 14 APR-16 APR 008/010-012/012-007/007
VI. Geomagnetic Activity Probabilities 14 APR to 16 APR
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 20% | 30% | 15% |
| Minor storm | 05% | 10% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 25% | 35% | 20% |
| Minor storm | 10% | 20% | 10% |
| Major-severe storm | 01% | 05% | 01% |
All times in UTC
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