Joint USAF/NOAA Report of Solar and Geophysical Activity 23 October 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Oct 23 2200 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 296 Issued at 2200Z on 23 Oct 2011
IA. Analysis of Solar Active Regions and Activity from 22/2100Z
to 23/2100Z: Solar activity was low. Region 1324 (N12W00) produced a
C2 X-ray flare at 23/1147Z as well as a few other optical subflares.
The region continues to slowly decay. New Region 1331 (N11W60)
emerged on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be low
with a slight chance for an isolated M-class flare. Regions 1324
(N12W00) and 1330 (N08E60) are the most likely source of flare
activity.
IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field was quiet. A greater than 10 MeV proton event
began at 23/1500Z. So far the observed peak flux was 13 pfu at
23/1535Z. The source of the event is believed to be yesterday’s
long-duration M1 flare at 22/1110Z in Region 1314 (N29, L=053).
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected be mostly quiet becoming quiet to unsettled with a chance
of active periods on 25 October. This activity is expected in
response to the arrival of a CME that occurred at 22/0058Z in
association with an eruptive filament. The greater than 10 MeV
proton event is expected to end by 24 October.
III. Event Probabilities 24 Oct-26 Oct
Class M 20/20/20
Class X 01/01/01
Proton 10/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 23 Oct 156
Predicted 24 Oct-26 Oct 150/145/140
90 Day Mean 23 Oct 122
V. Geomagnetic A Indices
Observed Afr/Ap 22 Oct 002/003
Estimated Afr/Ap 23 Oct 002/004
Predicted Afr/Ap 24 Oct-26 Oct 005/005-010/010-010/010
VI. Geomagnetic Activity Probabilities 24 Oct-26 Oct
A. Middle Latitudes
Active 05/30/30
Minor storm 01/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 10/40/40
Minor storm 05/10/10
Major-severe storm 01/01/01