:Product: 0526RSGA.txt
:Issued: 2011 May 26 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 146 Issued at 2200Z on 26 May 2011
IA.  Analysis of Solar Active Regions and Activity from  25/2100Z
to 26/2100Z:  Solar activity was low.  A fast emerging flux region
was numbered today as Region 1223 (S15E14).  This region produced
two C-class events as it evolved.  The first was a C1 at 25/2103Z
then followed by a second C1 at 25/2158Z.  It is configured as a Cso
group with a beta magnetic classification.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low to low with a chance for a C-class event.
IIA.  Geophysical Activity Summary 25/2100Z to 26/2100Z:
The geomagnetic field was mainly quiet with an active period reported
at 25/1800Z at mid-latitudes.  Observations from the ACE spacecraft
indicated a possible co-rotating interaction region (CIR) at around
25/1330Z.  Solar wind speed increased from around 340 to 390 km/s
and density jumped to 6 p/cc.  Interplanetary magnetic field changes
included an increase in Bt to +7 nT, while Bz dipped to -6 nT.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be mostly unsettled with isolated active periods, and
isolated minor storms possible at high-latitudes, for the next three
days (27-29 May).  Activity is expected due to a recurrent coronal
hole high speed stream.  In addition, a disappearing filament
observed at 25/0801Z may possibly disturb the field on day two (28
May).
III.  Event Probabilities 27 May-29 May
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           26 May 083
Predicted   27 May-29 May  085/085/085
90 Day Mean        26 May 108
V.  Geomagnetic A Indices
Observed Afr/Ap 25 May  002/004
Estimated Afr/Ap 26 May  005/007
Predicted Afr/Ap 27 May-29 May  010/010-015/015-010/012
VI.  Geomagnetic Activity Probabilities 27 May-29 May
A.  Middle Latitudes
Active                20/25/20
Minor storm           05/10/05
Major-severe storm    01/05/01
B.  High Latitudes
Active                30/35/30
Minor storm           10/15/10
Major-severe storm    05/05/05