Viewing archive of Thursday, 25 April 2002

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 2002 Apr 25 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 115 Issued at 2200Z on 25 Apr 2002

IA. Analysis of Solar Active Regions and Activity from 24-2100Z to 25-2100Z

Solar activity was moderate. Region 9912 (N11W65) produced an impulsive M1/1f flare at 24/2156 UTC associated with minor radio emission. This region continued to slowly decay. Region 9924 (S15W20), which emerged rapidly yesterday, began to gradually decay. Minor growth was observed in Region 9915 (N12E01). The remaining regions were unremarkable including newly numbered Region 9925 (S14W36).
IB. Solar Activity Forecast
Solar activity is expected to be low with an outside chance for an isolated low-level M-class flare.
IIA. Geophysical Activity Summary 24-2100Z to 25-2100Z
Geomagnetic field activity was at quiet levels during most of the period. The greater than 10 MeV proton event that began at 21/0225 UTC persisted, but just barely above event threshold (the maximum for this event was 2520 pfu at 21/2320 UTC).
IIB. Geophysical Activity Forecast
Geomagnetic field activity is expected to be at quiet to unsettled levels on 26 April. Unsettled to active levels are expected during 27 - 28 April due to recurrent coronal hole effects. The greater than 10 MeV proton event is expected to end early on 26 April.
III. Event Probabilities 26 Apr to 28 Apr
Class M30%30%30%
Class X01%01%01%
PCAFin progress
IV. Penticton 10.7 cm Flux
  Observed       25 Apr 167
  Predicted   26 Apr-28 Apr  170/170/175
  90 Day Mean        25 Apr 197
V. Geomagnetic A Indices
  Observed Afr/Ap 24 Apr  006/007
  Estimated     Afr/Ap 25 Apr  006/007
  Predicted    Afr/Ap 26 Apr-28 Apr  012/012-015/015-012/012
VI. Geomagnetic Activity Probabilities 26 Apr to 28 Apr
A. Middle Latitudes
Minor storm10%15%15%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm15%20%20%
Major-severe storm01%05%05%

All times in UTC

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