Viewing archive of Saturday, 21 August 2004

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 2004 Aug 21 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 234 Issued at 2200Z on 21 Aug 2004

IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z

Solar activity was very low. Occasional brightness fluctuations were noted, but no flare activity occurred. Region 661 (N07W33) contains minor magnetic complexity and white light area coverage of over 450 millionths, but has been stable for the past 48 hours. Region 663 (N11E52) has rotated fully into view as an elongated beta spot group with some minor magnetic mixing. Region 664 (S10E25) exhibited considerable growth this period and also displays some minor mixing. No new regions were numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be very low to low. Isolated C-class flares are possible.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was quiet to active with isolated minor storm periods. The disturbed periods are due to a slightly elevated solar wind speed (near 500 km/s) and predominantly southward IMF Bz.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet to active with isolated minor storm periods.
III. Event Probabilities 22 Aug to 24 Aug
Class M15%15%15%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       21 Aug 120
  Predicted   22 Aug-24 Aug  120/120/120
  90 Day Mean        21 Aug 109
V. Geomagnetic A Indices
  Observed Afr/Ap 20 Aug  009/014
  Estimated     Afr/Ap 21 Aug  020/020
  Predicted    Afr/Ap 22 Aug-24 Aug  015/015-012/015-012/015
VI. Geomagnetic Activity Probabilities 22 Aug to 24 Aug
A. Middle Latitudes
Minor storm10%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm15%10%10%
Major-severe storm05%01%01%

All times in UTC

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