Joint USAF/NOAA Report of Solar and Geophysical Activity 29 December 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Dec 29 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 363 Issued at 2200Z on 29 Dec 2011
IA. Analysis of Solar Active Regions and Activity from 28/2100Z
to 29/2100Z: Solar activity has been at moderate levels for the past
24 hours. Region 1389 (S23E58) produced the largest event of the
period, an M1/1F flare at 29/1350Z. Region 1398 continues to grow
and evolve as it rotates around the east limb.
IB. Solar Activity Forecast: Solar activity is expected to be at
low to moderate levels for the next three days (30 December – 01
January).
IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z:
The geomagnetic field has been at quiet to unsettled levels for
the past 24 hours. Solar wind speeds, as measured by the ACE
spacecraft, have shown an increase from 280 km/s to almost 450 km/s
in the past 24 hours. Signatures in the solar wind indicate the
possible arrivals of the forecasted CME’s, however the intensity was
lower than expected.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels for day one (30
December) as the effects of the CME’s wane. Predominantly
quiet levels are expected on day two (31 December). A return to
quiet to unsettled levels is expected on day three (01 January) as a
coronal hole high speed stream moves into a geoeffective position.
III. Event Probabilities 30 Dec-01 Jan
Class M 40/40/40
Class X 05/05/05
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 29 Dec 147
Predicted 30 Dec-01 Jan 145/145/145
90 Day Mean 29 Dec 144
V. Geomagnetic A Indices
Observed Afr/Ap 28 Dec 004/003
Estimated Afr/Ap 29 Dec 005/006
Predicted Afr/Ap 30 Dec-01 Jan 012/008-005/005-008/010
VI. Geomagnetic Activity Probabilities 30 Dec-01 Jan
A. Middle Latitudes
Active 15/05/10
Minor storm 05/01/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 20/10/15
Major-severe storm 20/05/15