Viewing archive of Monday, 11 October 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 Oct 11 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 284 Issued at 2200Z on 11 OCT 1999

IA. Analysis of Solar Active Regions and Activity from 10-2100Z to 11-2100Z

SOLAR ACTIVITY WAS LOW. TODAY'S ACTIVITY CONSISTED OF A FEW, LOW LEVEL C-CLASS EVENTS. OF THE 10 SPOTTED REGIONS ON THE DISK, NEW REGION 8731 (N10E62) WAS THE MOST ACTIVE WITH FREQUENT POINT BRIGHTENINGS AND PLAGE FLUCTUATIONS. REGION 8728 (N22E38) IS THE LARGEST GROUP ON THE DISK AT 560 MILLIONTHS AND SHOWS SOME MAGNETIC COMPLEXITY. THIS GROUP HAS INCREASED SIGNIFICANTLY OVER THE LAST 24 HOURS.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE MOSTLY LOW, BUT THERE IS A GOOD CHANCE FOR AN ISOLATED M-CLASS EVENT SOMETIME OVER THE NEXT THREE DAYS, ESPECIALLY GIVEN THE GROWTH AND COMPLEXITY OF REGION 8728. REGION 8731 IS EXPECTED TO PRODUCE OCCASIONAL C-CLASS FLARES OVER THE NEXT THREE DAYS.
IIA. Geophysical Activity Summary 10-2100Z to 11-2100Z
THE GEOMAGNETIC FIELD WAS AT QUIET TO ACTIVE LEVELS DURING THE PAST 24 HOURS. ACTIVE LEVELS DOMINATED FROM 0000-1500Z. SOLAR WIND MEASUREMENTS INDICATED THAT THE ACTIVITY WAS DUE TO A HIGH-SPEED, LOW-DENSITY CORONAL HOLE ASSOCIATED SOLAR WIND STREAM. THE GREATER THAN 2 MEV ELECTRONS ATTAINED HIGH FLUX VALUES DURING THE PAST 24 HOURS.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE UNSETTLED TO ACTIVE DURING THE NEXT 24 HOURS AS THE CURRENT DISTURBANCE SUBSIDES. A NEW ENHANCEMENT IN GEOMAGNETIC ACTIVITY IS EXPECTED ON THE 2ND AND 3RD DAYS AS A NEW SOLAR CORONAL HOLE WILL BE ROTATING INTO A GEOEFFECTIVE POSITION. MID-LATITUDES ARE FORECAST TO BE ACTIVE AND HIGH LATITUDES ARE EXPECTED TO BE AT MINOR STORM LEVELS.
III. Event Probabilities 12 OCT to 14 OCT
Class M35%35%35%
Class X05%05%05%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       11 OCT 167
  Predicted   12 OCT-14 OCT  170/175/180
  90 Day Mean        11 OCT 154
V. Geomagnetic A Indices
OBSERVED AFR/AP 10 OCT  018/028
ESTIMATED AFR/AP 11 OCT  020/022
PREDICTED AFR/AP 12 OCT-14 OCT  015/020-020/030-020/035
VI. Geomagnetic Activity Probabilities 12 OCT to 14 OCT
A. Middle Latitudes
Active30%40%40%
Minor storm15%20%20%
Major-severe storm10%10%10%
B. High Latitudes
Active35%40%40%
Minor storm15%25%25%
Major-severe storm05%15%15%

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