:Product: 20020425RSGA.txt
:Issued: 2002 Apr 25 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 115 Issued at 2200Z on 25 Apr 2002
IA.  Analysis of Solar Active Regions and Activity from  24/2100Z
to 25/2100Z:  Solar activity was moderate. Region 9912 (N11W65)
produced an impulsive M1/1f flare at 24/2156 UTC associated with
minor radio emission. This region continued to slowly decay. Region
9924 (S15W20), which emerged rapidly yesterday, began to gradually
decay. Minor growth was observed in Region 9915 (N12E01). The
remaining regions were unremarkable including newly numbered Region
9925 (S14W36).
IB.  Solar Activity Forecast:  Solar activity is expected to be low
with an outside chance for an isolated low-level M-class flare.
IIA.  Geophysical Activity Summary 24/2100Z to 25/2100Z:
Geomagnetic field activity was at quiet levels during most of the
period. The greater than 10 MeV proton event that began at 21/0225
UTC persisted, but just barely above event threshold (the maximum
for this event was 2520 pfu at 21/2320 UTC).
IIB.  Geophysical Activity Forecast:  Geomagnetic field activity is
expected to be at quiet to unsettled levels on 26 April. Unsettled
to active levels are expected during 27 - 28 April due to recurrent
coronal hole effects. The greater than 10 MeV proton event is
expected to end early on 26 April.
III.  Event Probabilities 26 Apr-28 Apr
Class M    30/30/30
Class X    01/01/01
Proton     01/01/01
PCAF       in progress
IV.  Penticton 10.7 cm Flux
Observed           25 Apr 167
Predicted   26 Apr-28 Apr  170/170/175
90 Day Mean        25 Apr 197
V.  Geomagnetic A Indices
Observed Afr/Ap 24 Apr  006/007
Estimated Afr/Ap 25 Apr  006/007
Predicted Afr/Ap 26 Apr-28 Apr  012/012-015/015-012/012
VI.  Geomagnetic Activity Probabilities 26 Apr-28 Apr
A.  Middle Latitudes
Active                25/35/35
Minor storm           10/15/15
Major-severe storm    01/01/01
B.  High Latitudes
Active                30/40/40
Minor storm           15/20/20
Major-severe storm    01/05/05