:Product: 20020511RSGA.txt
:Issued: 2002 May 11 2200 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Environment Center and the U.S. Air Force.
#
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 131 Issued at 2200Z on 11 May 2002
IA.  Analysis of Solar Active Regions and Activity from  10/2100Z
to 11/2100Z:  Solar activity was at moderate levels.  Region 9937
(S09W38) produced an M1/Sf flare at 11/1132 UTC with an associated
Type II radio sweep of 415 km/s and minor discrete radio bursts.
Increased magnetic complexity is apparent in this region with the
hint of a delta forming in the dominant spot, seen in the trailing
portion of spot cluster.  Region 9934 (S17W59) was fairly active
today, producing multiple C-class flares.  The largest was a C3/Sf
flare occurring at 11/1738 UTC.  This region remains the most
complex region on the disk.  New Region 9950 (S06E44) produced a
C2/Sf flare at 11/1650 UTC.  Region 9949 (S16W06) is also a newly
numbered region.
IB.  Solar Activity Forecast:  Solar activity is expected to be low
to moderate.  Regions 9934 and 9937 are both complex enough to
produced M-class flare activity.
IIA.  Geophysical Activity Summary 10/2100Z to 11/2100Z:
The geomagnetic field was at quiet to major storm levels.  Data from
the Advanced Composition Explorer (ACE) showed an increase in the
solar wind speed from roughly 350 to 450 km/s beginning at
approximately 11/0915 UTC.  The north-south component of the
interplanetary magnetic field remained strongly negative for several
hours thereafter.  A sudden impulse of 41 nT was observed at the
Boulder Magnetometer at 11/1028 UTC.  Major storm conditions were
observed at high latitudes from 11/1100 through 11/1800 UTC.
Uncertain as to the source(s) of the activity, although multiple
CME's were seen in SOHO/LASCO imagery on the eighth and ninth.
Source regions for CME's believed to have been from both the east
and west limbs.
IIB.  Geophysical Activity Forecast:  The geomagnetic field activity
is expected to be at predominantly quiet to unsettled levels.
Isolated minor storm conditions may occur on day three of the
forecast due to the M1/Sf flare that occurred at 11/1132 UTC.
III.  Event Probabilities 12 May-14 May
Class M    60/60/50
Class X    15/15/05
Proton     10/10/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           11 May 188
Predicted   12 May-14 May  190/195/190
90 Day Mean        11 May 187
V.  Geomagnetic A Indices
Observed Afr/Ap 10 May  019/017
Estimated Afr/Ap 11 May  035/040
Predicted Afr/Ap 12 May-14 May  012/015-008/010-012/012
VI.  Geomagnetic Activity Probabilities 12 May-14 May
A.  Middle Latitudes
Active                25/20/25
Minor storm           05/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                30/20/30
Minor storm           10/05/10
Major-severe storm    05/01/05