:Product: 20020424RSGA.txt
:Issued: 2002 Apr 24 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 114 Issued at 2200Z on 24 Apr 2002
IA.  Analysis of Solar Active Regions and Activity from  23/2100Z
to 24/2100Z:  Solar activity remained at low levels with occasional
C-class flares. The largest flare was a C4/1n at 24/1605 UTC from
Region 9912 (N09W51). Region 9912 showed gradual decay, mostly in
its trailer spots. Region 9913 (S16W44) produced occasional
subflares, a few of which reached C-class. It showed minor growth as
well as a minor mix of polarities. Region 9914 (N04E04) showed
gradual growth, but remained simply-structured. New Region 9924
(S17W07) emerged rapidly and produced isolated subflares. It was a
relatively small D- type spot group with minor polarity mixing
throughout. New Region 9923 (S03W31) was also numbered.
IB.  Solar Activity Forecast:  Solar activity is expected to be at
low to moderate levels. Isolated low-level M-class flares are
possible during the period.
IIA.  Geophysical Activity Summary 23/2100Z to 24/2100Z:
Geomagnetic field activity was at quiet to unsettled levels. The
greater than 10 MeV proton event that began at 21/0225 UTC
continued. The greater than 10 MeV proton flux was around 24.0 PFU
and gradually decreasing as the period ended.
IIB.  Geophysical Activity Forecast:  Geomagnetic field activity is
expected to be at quiet to unsettled levels during 25 - 26 April
increasing to unsettled to active levels on 27 April due to
recurrent coronal hole effects. The greater than 10 MeV proton event
is expected to end early in the period.
III.  Event Probabilities 25 Apr-27 Apr
Class M    40/40/40
Class X    05/05/05
Proton     50/05/05
PCAF       in progress
IV.  Penticton 10.7 cm Flux
Observed           24 Apr 177
Predicted   25 Apr-27 Apr  180/180/185
90 Day Mean        24 Apr 198
V.  Geomagnetic A Indices
Observed Afr/Ap 23 Apr  021/022
Estimated Afr/Ap 24 Apr  008/010
Predicted Afr/Ap 25 Apr-27 Apr  008/010-012/012-015/015
VI.  Geomagnetic Activity Probabilities 25 Apr-27 Apr
A.  Middle Latitudes
Active                20/25/35
Minor storm           10/10/15
Major-severe storm    01/01/01
B.  High Latitudes
Active                20/30/40
Minor storm           10/15/20
Major-severe storm    01/01/05