Viewing archive of Monday, 27 September 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 Sep 27 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 270 Issued at 2200Z on 27 SEP 1999IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z SOLAR ACTIVITY WAS LOW DUE TO A SINGLE C-CLASS EVENT.
THIS WAS A C2/SF FROM REGION 8704 (S12W60) AT 27/0912UT. ACTIVITY
FOR THE REST OF THE PERIOD WAS VERY LOW.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO CONTINUE
TO BE VERY LOW TO LOW.
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
THE GEOMAGNETIC FIELD WAS UNSETTLED TO MINOR STORM LEVELS. THESE
CONDITIONS WERE THE RESULT OF A HIGH SPEED CORONAL HOLE STREAM.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE WITH POSSIBLE MINOR STORM
CONDITIONS, ESPECIALLY AT HIGH LATITUDES, FOR THE FIRST DAY OF THE
FORECAST PERIOD. THESE CONDITIONS WOULD BE THE RESULT OF THE HIGH
SPEED CORONAL HOLE STREAM MENTIONED ABOVE. CONDITIONS SHOULD
DECREASE TO UNSETTLED TO ACTIVE ON THE SECOND DAY AND QUIET TO
UNSETTLED ON THE THIRD DAY OF THE PERIOD.
III. Event Probabilities 28 SEP to 30 SEP
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 27 SEP 124 Predicted 28 SEP-30 SEP 120/115/115 90 Day Mean 27 SEP 159
V. Geomagnetic A Indices
OBSERVED AFR/AP 26 SEP 013/015 ESTIMATED AFR/AP 27 SEP 035/040 PREDICTED AFR/AP 28 SEP-30 SEP 025/040-015/018-010/010
VI. Geomagnetic Activity Probabilities 28 SEP to 30 SEP
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 25% | 20% | 15% |
| Minor storm | 15% | 10% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 35% | 25% | 15% |
| Minor storm | 20% | 15% | 10% |
| Major-severe storm | 01% | 01% | 01% |
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