Joint USAF/NOAA Report of Solar and Geophysical Activity 20 August 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Aug 20 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 232 Issued at 2200Z on 20 Aug 2011
IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity was very low. There were occasional
B-class flares from Regions 1272 (S22E15) and 1271 (N16E10). Region
1271 decayed slightly to become a Dso type spot group with Beta
magnetic configuration. Region 1274 (N19E70) was numbered today; it
is currently small and magnetically simple.
IB. Solar Activity Forecast: Solar activity is expected to be very
low to low on Day 1 (21 Aug), becoming low with a slight chance for
moderate activity on Days 2 and 3 (22-23 Aug) with four active
regions expected to be on the disk at that time.
IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field was quiet and the solar wind at the ACE
spacecraft was unremarkable.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled on Day 1 (21 Aug) rising to
unsettled with a chance for active conditions on Day 2 (22 Aug).
The increase in activity is expected due to a co-rotating
interaction region followed by two negative polarity coronal hole
high speed streams. Day 3 (23 Aug) is expected to return to quiet
to unsettled conditions as effects from the first coronal hole begin
to wane.
III. Event Probabilities 21 Aug-23 Aug
Class M 05/20/20
Class X 01/01/01
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 20 Aug 101
Predicted 21 Aug-23 Aug 102/104/105
90 Day Mean 20 Aug 096
V. Geomagnetic A Indices
Observed Afr/Ap 19 Aug 001/002
Estimated Afr/Ap 20 Aug 003/003
Predicted Afr/Ap 21 Aug-23 Aug 007/008-010/012-007/008
VI. Geomagnetic Activity Probabilities 21 Aug-23 Aug
A. Middle Latitudes
Active 15/25/15
Minor storm 05/10/05
Major-severe storm 01/05/01
B. High Latitudes
Active 30/40/30
Minor storm 15/20/15
Major-severe storm 05/10/05