Viewing archive of Wednesday, 8 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 08 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 251 Issued at 2200Z on 08 SEP 1999

IA. Analysis of Solar Active Regions and Activity from 07-2100Z to 08-2100Z

SOLAR ACTIVITY WAS MODERATE. REGION 8690 (N13E47) PRODUCED AN M1/1B AT 1217Z. THE REGION PRODUCED ADDITIONAL SUBFLARES, BUT IS RATHER SMALL (50 MILLIONTHS) AND IS SHOWING ONLY SLOW GROWTH. REGION 8692 (S27E60) HAS ROTATED INTO VIEW AS AN E-TYPE REGION AND IS CURRENTLY THE LARGEST GROUP ON THE DISK AT 230 MILLIONTHS. THE GROUP WAS QUIET AND STABLE DURING THE PAST 24 HOURS. NEW REGION 8694 (S14W14) EMERGED ON THE DISK TODAY. AN ERUPTIVE PROMINENCE WAS OBSERVED ON THE SOUTHWEST LIMB (S34W90) FROM 1126-1220Z.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW. THERE IS A SLIGHT CHANCE, HOWEVER, FOR AN ISOLATED M-CLASS EVENT FROM REGION 8690 OR 8692.
IIA. Geophysical Activity Summary 07-2100Z to 08-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE. INITIALLY ACTIVE CONDITIONS WERE SEEN IN RESPONSE TO A HIGH-SPEED SOLAR WIND STREAM ASSOCIATED WITH A CORONAL HOLE. CONDITIONS TURNED MARKEDLY QUIET AFTER 0300Z IN RESPONSE TO A NORTHWARD TURNING OF THE BZ COMPONENT OF THE INTERPLANETARY MAGNETIC FIELD. UNSETTLED CONDITIONS RETURNED AFTER 12Z AS BZ TURNED STEADILY SOUTH FOR JUST OVER AN HOUR. QUIET CONDITIONS PREVAILED FOR THE LAST THREE HOURS OF THE REPORTING PERIOD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE MOSTLY UNSETTLED FOR THE NEXT THREE DAYS, BUT THERE IS A FAIR CHANCE FOR SOME ACTIVE PERIODS, ESPECIALLY AT HIGH LATITUDES. THE ENHANCED ACTIVITY IS POSSIBLE DUE TO ADDITIONAL CORONAL HOLES THAT WILL BE ROTATING INTO FAVORABLE POSITIONS.
III. Event Probabilities 09 SEP to 11 SEP
Class M25%25%25%
Class X01%01%01%
Proton01%01%01%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       08 SEP 106
  Predicted   09 SEP-11 SEP  105/105/100
  90 Day Mean        08 SEP 166
V. Geomagnetic A Indices
OBSERVED AFR/AP 07 SEP  012/017
ESTIMATED AFR/AP 08 SEP  010/010
PREDICTED AFR/AP 09 SEP-11 SEP  012/012-012/020-010/015
VI. Geomagnetic Activity Probabilities 09 SEP to 11 SEP
A. Middle Latitudes
Active25%20%20%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active35%25%25%
Minor storm10%10%10%
Major-severe storm05%05%05%

All times in UTC

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