Viewing archive of Wednesday, 21 September 2011

Solar activity report

Report of Solar-Geophysical Activity 2011 Sep 21 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 264 Issued at 2200Z on 21 Sep 2011

IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z

Solar activity was moderate. An M1 flare was observed at 21/1223Z from Region 1301 (N20E41). Regions 1295 (N22W47) and 1301 showed increases in area and produced occasional C-class flares during the period. Three CMEs were observed towards the NE quadrant, none of which are expected to be geoeffective.
IB. Solar Activity Forecast
Solar activity is expected to be low with a chance for isolated M-class flares from Regions 1295 and 1301 during the period (22-24 September).
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was at quiet levels at mid-latitudes, with isolated unsettled to active levels at high-latitudes.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at predominantly quiet levels during the period (22-24 September).
III. Event Probabilities 22 Sep to 24 Sep
Class M45%45%45%
Class X10%10%10%
IV. Penticton 10.7 cm Flux
  Observed       21 Sep 144
  Predicted   22 Sep-24 Sep  144/144/140
  90 Day Mean        21 Sep 104
V. Geomagnetic A Indices
  Observed Afr/Ap 20 Sep  006/006
  Estimated     Afr/Ap 21 Sep  004/005
  Predicted    Afr/Ap 22 Sep-24 Sep  005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 22 Sep to 24 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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