Joint USAF/NOAA Report of Solar and Geophysical Activity 31 December 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Dec 31 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 365 Issued at 2200Z on 31 Dec 2011
IA. Analysis of Solar Active Regions and Activity from 30/2100Z
to 31/2100Z: Solar activity was moderate. There were two M-class
x-ray flares from Region 1389 (S23E31), the largest of which was a
M2/Sf at 31/1315Z accompanied by a 150 pfu tenflare. The second was
a M1/1F at 31/1626Z. This region was classified as an Ekc type
group with beta-gamma characteristics. Region 1386 was also active,
producing a C1/Sf flare at 31/1731Z. The remaining regions were
stable.
IB. Solar Activity Forecast: Solar activity is expected to remain
at predominantly low levels, with a chance for occasional M-class
activity from Region 1389.
IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z:
The geomagnetic field was quiet. Solar wind speed at the ACE
spacecraft was about 350 km/s and Bz was mostly neutral to slightly
negative.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to reach unsettled levels for the next three days (1-3
January) as a recurrent coronal hole high speed stream becomes
geoeffective. There is a slight chance for active conditions during
this period.
III. Event Probabilities 01 Jan-03 Jan
Class M 40/40/40
Class X 05/05/05
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 31 Dec 133
Predicted 01 Jan-03 Jan 135/135/135
90 Day Mean 31 Dec 144
V. Geomagnetic A Indices
Observed Afr/Ap 30 Dec 005/005
Estimated Afr/Ap 31 Dec 000/003
Predicted Afr/Ap 01 Jan-03 Jan 008/010-007/010-008/008
VI. Geomagnetic Activity Probabilities 01 Jan-03 Jan
A. Middle Latitudes
Active 10/10/10
Minor storm 05/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 15/15/15
Major-severe storm 15/15/15