Viewing archive of Tuesday, 7 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 07 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 250 Issued at 2200Z on 07 SEP 1999

IA. Analysis of Solar Active Regions and Activity from 06-2100Z to 07-2100Z

SOLAR ACTIVITY WAS LOW. THERE WERE TWO C-CLASS FLARES WHICH WERE NOT OBSERVED OPTICALLY: A C1.7 AT 06/2112Z AND A C1.2 AT 07/1358Z. REGION 8690 (N13E60) HAS ROTATED MORE FULLY INTO VIEW AND IS AN 80 MILLIONTHS D-TYPE GROUP. A NEW REGION 8691 EMERGED NEAR S30W32 DURING THE PAST 24 HOURS. NEW REGIONS 8692 (S25E74) AND 8693 (N12E79) ROTATED INTO VIEW. BOTH OF THESE GROUPS SHOW SPOTS WITH PENUMBRA.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW.
IIA. Geophysical Activity Summary 06-2100Z to 07-2100Z
THE GEOMAGNETIC FIELD RANGED FROM QUIET TO ACTIVE LEVELS. ACE REAL-TIME SOLAR WIND MEASUREMENTS INDICATE THE ARRIVAL OF A HIGH-SPEED, LOW DENSITY SOLAR WIND STREAM AT ABOUT 07/0900Z. THE HIGH VELOCITY AND FREQUENTLY OSCILLATING BZ COMPONENT OF THE MAGNETIC FIELD RESULTED IN AN INCREASE IN ACTIVITY TO UNSETTLED TO ACTIVE LEVELS.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE MOSTLY UNSETTLED FOR THE NEXT THREE DAYS. THERE IS A FAIR CHANCE FOR SOME ACTIVE PERIODS DURING THE NEXT 24 HOURS, HOWEVER, IN RESPONSE TO THE HIGH SPEED SOLAR WIND STREAM.
III. Event Probabilities 08 SEP to 10 SEP
Class M05%05%05%
Class X01%01%01%
Proton01%01%01%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       07 SEP 112
  Predicted   08 SEP-10 SEP  115/115/115
  90 Day Mean        07 SEP 166
V. Geomagnetic A Indices
OBSERVED AFR/AP 06 SEP  004/006
ESTIMATED AFR/AP 07 SEP  015/013
PREDICTED AFR/AP 08 SEP-10 SEP  015/013-012/013-010/010
VI. Geomagnetic Activity Probabilities 08 SEP to 10 SEP
A. Middle Latitudes
Active50%25%15%
Minor storm15%10%10%
Major-severe storm05%05%05%
B. High Latitudes
Active50%35%20%
Minor storm20%15%10%
Major-severe storm10%05%05%

All times in UTC

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