Joint USAF/NOAA Report of Solar and Geophysical Activity 28 October 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Oct 28 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 301 Issued at 2200Z on 28 Oct 2011
IA. Analysis of Solar Active Regions and Activity from 27/2100Z
to 28/2100Z: Solar activity was low. Three C-flares occurred during
the past 24 hours, one from Region 1333 (N15W02) and two from Region
1324 (N13W63). Region 1324 showed emergence of new flux during the
past 24 hours. Region 1333’s growth has slowed considerably and the
region is currently a small D-type sunspot group with about 50
millionths in sunspot area. Region 1330 (N08W09) continues to be the
largest group on the disk with about 450 millionths area and a
beta-gamma magnetic classification, but did not produce any flares.
A CME was noted from the northeast limb entering the LASCO C3 field
of view around 1254Z on the 27th and was associated with a filament
eruption and post eruptive loop arcade in the northeast quadrant.
The CME appears to be moving too far north of the ecliptic to be
geoeffective. An additional CME was observed off the southwest limb
and entered the C3 field of view at 0218Z on the 28th. STEREO
coronagraph observations clearly showed that this was a backsided
event and therefore the event is not expected to be geoeffective.
IB. Solar Activity Forecast: Solar activity is expected to be low.
There is a slight chance for an isolated M-class event with Regions
1330, 1324, and 1333 the most likely sources.
IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z:
The geomagnetic field was quiet.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet for the first part of day one (29 October). An
increase to unsettled levels with a chance for active periods is
expected beginning late on the 29th and continuing through the first
and second days (30-31 October). The increase is expected due to a
high speed stream from coronal hole.
III. Event Probabilities 29 Oct-31 Oct
Class M 15/15/15
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 28 Oct 134
Predicted 29 Oct-31 Oct 135/135/130
90 Day Mean 28 Oct 124
V. Geomagnetic A Indices
Observed Afr/Ap 27 Oct 004/004
Estimated Afr/Ap 28 Oct 003/003
Predicted Afr/Ap 29 Oct-31 Oct 007/008-010/010-010/010
VI. Geomagnetic Activity Probabilities 29 Oct-31 Oct
A. Middle Latitudes
Active 10/25/25
Minor storm 05/15/15
Major-severe storm 01/05/05
B. High Latitudes
Active 15/35/35
Minor storm 05/25/25
Major-severe storm 01/15/15