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

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Aug 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 240 Issued at 2200Z on 28 Aug 2011
IA. Analysis of Solar Active Regions and Activity from 27/2100Z
to 28/2100Z: Solar activity was very low. New Region 1281 (S21E64)
produced occasional optical subflares during the period, two of
which were associated with B-class x-ray flares. No significant
activity was noted in the remaining spot groups. A weak Type II
radio sweep occurred at 28/0420Z, likely associated with a filament
disappearance from beyond the west limb. There were no
Earth-directed CMEs observed during the period.
IB. Solar Activity Forecast: Solar activity is expected to be very
low during the period (29 – 31 August) with a chance for an isolated
C-class flare.
IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z:
The geomagnetic field was quiet.
IIB. Geophysical Activity Forecast: Geomagnetic field activity is
expected to be at quiet to unsettled levels on day 1 (29 August).
Quiet geomagnetic conditions are expected during days 2 – 3 (30 – 31
August).
III. Event Probabilities 29 Aug-31 Aug
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 28 Aug 101
Predicted 29 Aug-31 Aug 100/098/095
90 Day Mean 28 Aug 097
V. Geomagnetic A Indices
Observed Afr/Ap 27 Aug 003/005
Estimated Afr/Ap 28 Aug 005/008
Predicted Afr/Ap 29 Aug-31 Aug 008/008-005/005-005/005
VI. Geomagnetic Activity Probabilities 29 Aug-31 Aug
A. Middle Latitudes
Active 20/15/15
Minor storm 05/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 25/20/15
Minor storm 10/05/01
Major-severe storm 01/01/01