Report of Solar-Geophysical Activity

Issued: 2011 Sep 22 2205 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity
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-25 Sep
Class M    70/70/70
Class X    20/20/20
Proton     10/10/10
PCAF       green
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-25 Sep
A.  Middle Latitudes
Active                05/05/10
Minor storm           01/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                10/10/15
Minor storm           01/01/01
Major-severe storm    01/01/01