:Product: 0818RSGA.txt
:Issued: 2011 Aug 18 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 230 Issued at 2200Z on 18 Aug 2011
IA.  Analysis of Solar Active Regions and Activity from  17/2100Z
to 18/2100Z:  Solar activity was low.  Both Regions 1271 (N15E38) and
1272 (S22E41) produced C1/Sf flares during the past 24 hours. 
Region 1271 became more consolidated during the period, but remained
a large Ehc type spot group with beta magnetic characteristics.
IB.  Solar Activity Forecast:  Solar activity is expected to be low
with a chance for moderate activity.  The continued persistence of
Region 1271, as well as the return of old Region 1261 on Day 2 (20
Aug), make moderate activity more probable.  During the last
rotation, old Region 1261 produced five M-class events including an
M9 and CME on 04 August.
IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field was quiet and the ambient solar wind
unremarkable. The greater than 2 MeV electron flux at geosynchronous
orbit reached high levels during the period.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be predominantly quiet for the first two days of the
forecast period (19-20 Aug).  A recurrent coronal hole high speed
stream is expected to become geoeffective on Day 3 (21 Aug) leading
to unsettled conditions with a chance for active periods at high
latitudes.
III.  Event Probabilities 19 Aug-21 Aug
Class M    45/45/45
Class X    10/10/10
Proton     01/01/01
PCAF       Green
IV.  Penticton 10.7 cm Flux
Observed           18 Aug 098
Predicted   19 Aug-21 Aug  098/100/100
90 Day Mean        18 Aug 096
V.  Geomagnetic A Indices
Observed Afr/Ap 17 Aug  006/006
Estimated Afr/Ap 18 Aug  005/005
Predicted Afr/Ap 19 Aug-21 Aug  005/005-005/005-010/012
VI.  Geomagnetic Activity Probabilities 19 Aug-21 Aug
A.  Middle Latitudes
Active                05/10/20
Minor storm           01/05/05
Major-severe storm    01/05/05
B.  High Latitudes
Active                05/10/50
Minor storm           05/05/15
Major-severe storm    01/01/10