Joint USAF/NOAA Report of Solar and Geophysical Activity 23 September 2012

:Product: Report of Solar-Geophysical Activity
:Issued: 2012 Sep 23 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 267 Issued at 2200Z on 23 Sep 2012
IA. Analysis of Solar Active Regions and Activity from 22/2100Z
to 23/2100Z: Solar activity was at low levels. The largest event of
the period was a long duration C1 x-ray flare at 23/1556Z from an
area of enhanced emission located behind the east limb. Region 1577
(N08E30) indicated the most change during the period developing
numerous intermediate spots. The remaining regions were quiet and
stable. No Earth-directed CMEs were observed.
IB. Solar Activity Forecast: Solar activity is expected to be at
low levels with a slight chance for M-class activity all three days
of the forecast period (24 – 26 September) as active regions are
expected to rotate onto the visible disk.
IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field was at quiet levels. ACE satellite
measurements indicated a steady decline in wind speed from about 400
km/s to near 350 km/s while the Bz component of the interplanetary
magnetic field did not vary much beyond +/- 4 nT.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at predominately quiet levels all three days of the
forecast period (24 – 26 September).
III. Event Probabilities 24 Sep-26 Sep
Class M 10/15/15
Class X 01/01/01
Proton 01/01/01
PCAF green
IV. Penticton 10.7 cm Flux
Observed 23 Sep 134
Predicted 24 Sep-26 Sep 135/140/145
90 Day Mean 23 Sep 123
V. Geomagnetic A Indices
Observed Afr/Ap 22 Sep 003/006
Estimated Afr/Ap 23 Sep 002/003
Predicted Afr/Ap 24 Sep-26 Sep 004/005-005/005-004/005
VI. Geomagnetic Activity Probabilities 24 Sep-26 Sep
A. Middle Latitudes
Active 05/05/05
Minor storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 10/10/10
Minor storm 01/01/01
Major-severe storm 01/01/01