Viewing archive of Friday, 9 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 09 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 099 Issued at 2200Z on 09 APR 1999IA. Analysis of Solar Active Regions and Activity from 08-2100Z to 09-2100Z SOLAR ACTIVITY RETURNED TO LOW LEVELS. REGION 8508
(N23W01) STABILIZED AND PRODUCED SEVERAL LOW LEVEL C-CLASS
SUBFLARES. MIXED POLARITIES REMAINED IN THIS REGION BUT OVERALL THE
REGION BECAME LESS COMPLEX AND MAGNETIC GRADIENTS LESSENED. OTHER
DISK REGIONS WERE STABLE OR DECLINING.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
FOR THE NEXT THREE DAYS. REGION 8508 IS CAPABLE OF PRODUCING AN
ISOLATED M-CLASS EVENT BUT THAT POSSIBILITY IS DECREASING DUE TO
REGION SIMPLIFICATION.
IIA. Geophysical Activity Summary 08-2100Z to 09-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. ENERGETIC ELECTRON
FLUXES AT GEOSYNCHRONOUS ORBIT DECREASED TO MODERATE LEVELS DURING
THE PERIOD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD SHOULD
REMAIN AT QUIET TO UNSETTLED LEVELS FOR THE NEXT THREE DAYS.
III. Event Probabilities 10 APR to 12 APR
| Class M | 25% | 25% | 25% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 09 APR 136 Predicted 10 APR-12 APR 132/128/124 90 Day Mean 09 APR 135
V. Geomagnetic A Indices
OBSERVED AFR/AP 08 APR 010/009 ESTIMATED AFR/AP 09 APR 008/010 PREDICTED AFR/AP 10 APR-12 APR 010/010-008/008-005/005
VI. Geomagnetic Activity Probabilities 10 APR to 12 APR
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 10% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 10% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 05% | 01% | 01% |
All times in UTC
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