Joint USAF/NOAA Report of Solar and Geophysical Activity 21 September 2012

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 Sep 21 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 265 Issued at 2200Z on 21 Sep 2012
IA. Analysis of Solar Active Regions and Activity from 20/2100Z
to 21/2100Z: Solar activity was very low. The largest x-ray event
was a B8/Sf at 21/1221Z produced by Region 1573 (N18W04). The
largest spot group on the solar disk, Region 1575 (N08E37), remains
near 250 millionths in area with a Beta magnetic configuration. Two
asymmetrical partial halo CMEs were observed in SOHO LASCO during
the period. Both events were determined to be backside sourced, and
are not expected to impact Earth.
IB. Solar Activity Forecast: Solar activity is expected to be very
low to low for the next 3 days (22-24 September).
IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z:
The geomagnetic field was quiet during the period, despite the
influence of a weak coronal hole (CH) high speed stream.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled for day 1 (22 September) as CH
effects wane. Conditions are expected to be mostly quiet for days
2-3 (23-24 September).
III. Event Probabilities 22 Sep-24 Sep
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 21 Sep 117
Predicted 22 Sep-24 Sep 118/120/120
90 Day Mean 21 Sep 122
V. Geomagnetic A Indices
Observed Afr/Ap 20 Sep 010/010
Estimated Afr/Ap 21 Sep 005/006
Predicted Afr/Ap 22 Sep-24 Sep 008/008-006/005-006/005
VI. Geomagnetic Activity Probabilities 22 Sep-24 Sep
A. Middle Latitudes
Active 10/01/01
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor storm 20/10/10
Major-severe storm 15/05/05