Report of Solar-Geophysical Activity

Issued: 2011 Dec 22 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 356 Issued at 2200Z on 22 Dec 2011

IA.  Analysis of Solar Active Regions and Activity from  21/2100Z
to 22/2100Z:  Solar activity was low.  Region 1381 (S18W28) produced
a C5/Sf flare at 22/0208Z.  This flare was accompanied by Type II
(921 km/s) and Type IV radio emissions with a CME.  A faint CME was
observed in STEREO-A COR2 imagery at 22/0509Z.  Plane of sky
analysis suggested a speed of roughly 150 km/s for the ejecta.  
This event is not expected to be geoeffective.  Intermediate spots
diminished in Regions 1384 (N12E37) and 1376 (N18W72) while Regions
1382( S19W21) and 1383 (N03E25) both showed signs of growth.
IB.  Solar Activity Forecast:  Solar activity is expected to remain
low for the next three days (23-25 December), with a slight chance
for an M-class event.
IIA.  Geophysical Activity Summary 21/2100Z to 22/2100Z:
The geomagnetic field was quiet.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to remain at mostly quiet levels for the next three days
(23-25 December).
III.  Event Probabilities 23 Dec-25 Dec
Class M    15/10/10
Class X    01/01/01
Proton     01/01/01
PCAF       Green
IV.  Penticton 10.7 cm Flux
Observed           22 Dec 146
Predicted   23 Dec-25 Dec  145/140/140
90 Day Mean        22 Dec 145
V.  Geomagnetic A Indices
Observed Afr/Ap 21 Dec  005/004
Estimated Afr/Ap 22 Dec  005/002
Predicted Afr/Ap 23 Dec-25 Dec  005/005-005/005-005/005
VI.  Geomagnetic Activity Probabilities 23 Dec-25 Dec
A.  Middle Latitudes
Active                05/05/05
Minor storm           01/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor storm           10/10/10
Major-severe storm    05/05/05