Viewing archive of Thursday, 22 September 2011

Solar activity report

Report of Solar-Geophysical Activity 2011 Sep 22 2225 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

:::::::::: CORRECTED COPY :::::::::: SDF Number 265 Issued at 2200Z on 22 Sep 2011

IA. Analysis of Solar Active Regions and Activity from 21-2100Z to 22-2100Z

Activity was high. New Region 1302 (N11E74) produced a long-duration X1/2n flare at 22/1101Z. The X1 flare was associated with Types II and IV radio sweeps, a 970 sfu Tenflare, and a full halo CME. The CME, already in progress in SOHO LASCO images at 22/1330Z, had an estimated speed of around 1392 km/s. This CME is not expected to be geoeffective.
IB. Solar Activity Forecast
Solar activity is expected to be high, with a slight chance for another X-class flare from Region 1302.
IIA. Geophysical Activity Summary 21-2100Z to 22-2100Z
The geomagnetic field was quiet.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet on days one and two (23-24 September). Quiet to unsettled levels, with isolated active levels at high latitudes, are expected on day three (25 September), due to a weak coronal hole high-speed stream.
III. Event Probabilities 23 Sep to 25 Sep
Class M70%70%70%
Class X20%20%20%
IV. Penticton 10.7 cm Flux
  Observed       22 Sep 151
  Predicted   23 Sep-25 Sep  155/160/165
  90 Day Mean        22 Sep 105
V. Geomagnetic A Indices
  Observed Afr/Ap 21 Sep  002/005
  Estimated     Afr/Ap 22 Sep  003/004
  Predicted    Afr/Ap 23 Sep-25 Sep  005/005-005/005-007/008
VI. Geomagnetic Activity Probabilities 23 Sep to 25 Sep
A. Middle Latitudes
Minor storm01%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm01%01%01%
Major-severe storm01%01%01%

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