Viewing archive of Friday, 23 September 2011

Solar activity report

Report of Solar-Geophysical Activity 2011 Sep 23 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 266 Issued at 2200Z on 23 Sep 2011

IA. Analysis of Solar Active Regions and Activity from 22-2100Z to 23-2100Z

Solar activity was moderate. An M1/1n flare was observed at 23/0159Z from Region 1295 (N25W74) along with several C-class flares, including an long-duration flare at 23/0850Z. Region 1302 (N13E58) remains the most significant region on the disk as an Eki Beta-Gamma with an area of 780 millionths.
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 22-2100Z to 23-2100Z
The geomagnetic field was quiet. The 10 MeV protons at geosynchronous orbit are expected to exceed the 10 pfu threshold during the period.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet on day one (24 September). Quiet, with isolated unsettled levels, are expected on day two (25 September), due to a weak coronal hole high-speed stream. Quiet levels are expected on day three (26 September).
III. Event Probabilities 24 Sep to 26 Sep
Class M70%70%70%
Class X20%20%20%
IV. Penticton 10.7 cm Flux
  Observed       23 Sep 158
  Predicted   24 Sep-26 Sep  160/165/170
  90 Day Mean        23 Sep 106
V. Geomagnetic A Indices
  Observed Afr/Ap 22 Sep  002/003
  Estimated     Afr/Ap 23 Sep  002/004
  Predicted    Afr/Ap 24 Sep-26 Sep  005/005-007/008-005/005
VI. Geomagnetic Activity Probabilities 24 Sep to 26 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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