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 UTC
Prepared 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 1999

IA. 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 M50%40%30%
Class X10%10%05%
Proton10%10%05%
PCAFGREEN
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
Active20%15%10%
Minor storm15%10%05%
Major-severe storm05%05%01%
B. High Latitudes
Active25%20%20%
Minor storm20%15%10%
Major-severe storm20%05%05%

All times in UTC

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