Viewing archive of Wednesday, 28 September 2011

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 2011 Sep 28 2205 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 271 Issued at 2200Z on 28 Sep 2011

IA. Analysis of Solar Active Regions and Activity from 27-2100Z to 28-2100Z

Solar activity was moderate. Region 1302 (N13W04) produced an M1/1n flare at 28/1328Z. Region 1302 also produced a C9/1n flare at 28/1232Z associated with a 390 sfu Tenflare. Occasional C-class flares were observed during the period. New Region 1307 (N14E75) was numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be low with a chance for an isolated M- and X-flare from Region 1302.
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
The geomagnetic field ranged from unsettled to minor storm levels, due to substorming. The greater than 10 MeV protons at geosynchronous orbit were enhanced during the period. Wind speeds reached 548 km/s at 27/2132Z and decreased to approximately 450 km/s at 28/1716Z.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet to unsettled, with isolated active levels at high latitudes, on day one (29 September). Predominantly quiet levels are expected on days two and three (30 September-01 October).
III. Event Probabilities 29 Sep to 01 Oct
Class M50%50%50%
Class X30%30%30%
IV. Penticton 10.7 cm Flux
  Observed       28 Sep 133
  Predicted   29 Sep-01 Oct  130/130/125
  90 Day Mean        28 Sep 109
V. Geomagnetic A Indices
  Observed Afr/Ap 27 Sep  022/030
  Estimated     Afr/Ap 28 Sep  014/022
  Predicted    Afr/Ap 29 Sep-01 Oct  008/012-005/005-008/008
VI. Geomagnetic Activity Probabilities 29 Sep to 01 Oct
A. Middle Latitudes
Minor storm01%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm05%01%01%
Major-severe storm01%01%01%

All times in UTC

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