Joint USAF/NOAA Report of Solar and Geophysical Activity 19 August 2011

:Product: Report of Solar-Geophysical Activity
:Issued: 2011 Aug 19 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 231 Issued at 2200Z on 19 Aug 2011
IA. Analysis of Solar Active Regions and Activity from 18/2100Z
to 19/2100Z: Solar activity was very low. Region 1271 (N16E25) did
not produce any significant activity during the past 24 hours,
although it did retain a large Esi type spot group with beta-gamma
magnetic characteristics. The other two regions were small and
simple.
IB. Solar Activity Forecast: Solar activity is expected to be low
on Day 1 (20 Aug), becoming low with a chance for moderate activity
on Days 2 and 3 (21-22 Aug) when old Region 1261 (N15, L=347)
returns.
IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z:
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 at quiet levels on Day 1 (20 Aug) and rise to
unsettled levels with a chance for active conditions on Day 2 (21
Aug). The rise in activity is expected with the arrival of a
coronal hole high speed stream. By Day 3 (22 Aug), a return to
mostly quiet conditions is expected as weak coronal hole effects
wane.
III. Event Probabilities 20 Aug-22 Aug
Class M 05/45/45
Class X 01/05/10
Proton 01/01/01
PCAF Green
IV. Penticton 10.7 cm Flux
Observed 19 Aug 098
Predicted 20 Aug-22 Aug 100/100/100
90 Day Mean 19 Aug 096
V. Geomagnetic A Indices
Observed Afr/Ap 18 Aug 001/003
Estimated Afr/Ap 19 Aug 003/003
Predicted Afr/Ap 20 Aug-22 Aug 005/005-010/012-005/005
VI. Geomagnetic Activity Probabilities 20 Aug-22 Aug
A. Middle Latitudes
Active 15/25/10
Minor storm 05/10/05
Major-severe storm 01/05/05
B. High Latitudes
Active 10/50/20
Minor storm 05/15/05
Major-severe storm 01/10/05