Viewing archive of Wednesday, 1 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 01 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 244 Issued at 2200Z on 01 SEP 1999IA. Analysis of Solar Active Regions and Activity from 31-2100Z to 01-2100Z SOLAR ACTIVITY HAS BEEN LOW FOR THE PAST 24 HOURS. THE
LARGEST EVENT WAS A C6/SF FLARE FROM REGION 8674 (S24W72). NO NEW
REGIONS WERE NUMBERED, THE X-RAY BACKGROUND LEVEL WAS NEAR OR
EXCEEDED C1 FOR MOST OF THE PERIOD. SURGING WAS REPORTED ON THE
WEST LIMB NEAR S20 AS REGION 8673 (S19W94) ROUNDED THE LIMB. A
FILAMENT LOCATED NEAR S10W25 ON 8/31/1500 UT WAS GONE BY 9/01/1538
UT. FILAMENT GROWTH WAS NOTED NEAR S25W10.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE FOR THE NEXT THREE DAYS. ISOLATED M-CLASS EVENTS ARE
POSSIBLE FROM REGION 8674 AND REGION 8681. BOTH REGIONS ARE
MODERATELY MAGNETICALLY COMPLEX. DEVELOPMENT MAY BE OCCURRING IN
THE SOUTHWEST QUADRANT NEAR REGIONS 8686 (S24W09) AND 8679 (S36W17).
IIA. Geophysical Activity Summary 31-2100Z to 01-2100Z
THE GEOMAGNETIC FIELD HAS BEEN UNSETTLED TO ACTIVE FOR THE PAST 24
HOURS, WITH ONE PERIOD AT MINOR STORMS LEVELS (06-09 UT). THIS
ACTIVITY WAS CAUSED BY RELATIVELY STEADY, MODERATE VELOCITY (NEAR
550 KM/S) SOLAR WIND WITH A CONSISTENTLY SOUTHWARD MAGNETIC FIELD
(NEAR 5 NT). THE SECTOR POLARITY WAS POSITIVE (AWAY). ENERGETIC
ELECTRON FLUXES AT GEOSYNCHRONOUS ORBIT REACHED HIGH LEVELS DURING
THE PERIOD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO PERSIST AT UNSETTLED TO ACTIVE CONDITIONS, WITH ISOLATED
PERIODS AT STORM LEVELS. THE OVERALL LEVEL OF ACTIVITY IS EXPECTED
TO DECLINE TOWARD PREDOMINATELY UNSETTLED CONDITIONS BY THE END OF
THE FORECAST PERIOD. A SOLAR PROTON EVENT IS POSSIBLE BUT IS NOT
CONSIDERED LIKELY.
III. Event Probabilities 02 SEP to 04 SEP
| Class M | 50% | 40% | 30% |
| Class X | 10% | 10% | 05% |
| Proton | 10% | 10% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 01 SEP 163 Predicted 02 SEP-04 SEP 155/150/145 90 Day Mean 01 SEP 169
V. Geomagnetic A Indices
OBSERVED AFR/AP 31 AUG 012/018 ESTIMATED AFR/AP 01 SEP 020/018 PREDICTED AFR/AP 02 SEP-04 SEP 018/012-015/012-010/010
VI. Geomagnetic Activity Probabilities 02 SEP to 04 SEP
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 20% | 15% | 10% |
| Minor storm | 15% | 10% | 05% |
| Major-severe storm | 05% | 05% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 25% | 20% | 20% |
| Minor storm | 20% | 15% | 10% |
| Major-severe storm | 20% | 05% | 05% |
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