Joint USAF/NOAA Report of Solar and Geophysical Activity 13 December 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Dec 13 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 347 Issued at 2200Z on 13 Dec 2011
IA. Analysis of Solar Active Regions and Activity from 12/2100Z
to 13/2100Z: Solar activity was low. There were three, low-level
C-class flares during the past 24 hours, all from Region 1367
(S18W89). Region 1367 showed signs of new flux emerging as it was
rotating around the west limb. Region 1374 (S18E01) continues to be
the largest group on the disk (140 millionths) and shows a very
small delta configuration in the leader spot region, but was quiet
and stable. Two erupting prominences which led to coronal mass
ejections were observed: the first just entered the LASCO/C2 field
of view at 12/1848Z, slightly west of the north pole and the second
entered LASCO/C2 field of view at 13/0200Z off the southwest limb.
Neither of these CME’s are expected to be geoeffective.
IB. Solar Activity Forecast: Solar activity is expected to be low.
IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z:
The geomagnetic field was mostly quiet. There was an interval of
unsettled levels from 0900-1500Z at high latitudes.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet for day one (14 December). Quiet levels with a
chance for some unsettled periods are expected for day two (15
December) due to a possible brief, glancing blow from an erupting
prominence/CME that was observed on 11 December. Quiet levels are
expected to prevail for the third day (16 December).
III. Event Probabilities 14 Dec-16 Dec
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 13 Dec 133
Predicted 14 Dec-16 Dec 133/132/130
90 Day Mean 13 Dec 146
V. Geomagnetic A Indices
Observed Afr/Ap 12 Dec 004/004
Estimated Afr/Ap 13 Dec 003/004
Predicted Afr/Ap 14 Dec-16 Dec 005/005-007/008-005/005
VI. Geomagnetic Activity Probabilities 14 Dec-16 Dec
A. Middle Latitudes
Active 05/10/05
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 10/15/10
Major-severe storm 05/10/05