Viewing archive of Wednesday, 31 July 2002

Solar activity report

Report of Solar-Geophysical Activity 2002 Jul 31 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 212 Issued at 2200Z on 31 Jul 2002

IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 31-2100Z

Solar activity was at moderate levels. Region 39 (S15W44) produced an M1/Sb flare at 31/0153 UTC with associated discrete frequency radio burst. This region continues its gradual decay but maintains a delta configuration in the leader spot. Region 50 (S08W32) has shown growth in area and spot count while maintaining its beta-gamma magnetic configuration. Region 44 (S21W49) appears to have been relatively stable in the last 24 hours. New Region 56 (N04E49) was numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be moderate. M-class activity is expected from Region 39, Region 44 or Region 50. An isolated X-class event is possible from Region 39.
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
The geomagnetic field was at quiet to unsettled levels. A weak shock was detected at the L1 position by the NASA/ACE spacecraft at approximately 31/1100 UTC. The Bz component of the IMF was northward resulting in little geomagnetic activity.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet to unsettled. Isolated active conditions are possible on days one and two of the forecast period.
III. Event Probabilities 01 Aug to 03 Aug
Class M75%75%75%
Class X20%20%20%
IV. Penticton 10.7 cm Flux
  Observed       31 Jul 209
  Predicted   01 Aug-03 Aug  205/200/200
  90 Day Mean        31 Jul 167
V. Geomagnetic A Indices
  Observed Afr/Ap 30 Jul  005/008
  Estimated     Afr/Ap 31 Jul  009/012
  Predicted    Afr/Ap 01 Aug-03 Aug  012/015-015/015-010/010
VI. Geomagnetic Activity Probabilities 01 Aug to 03 Aug
A. Middle Latitudes
Minor storm10%15%05%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm15%20%10%
Major-severe storm01%01%01%

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