:Product: 20020824RSGA.txt
:Issued: 2002 Aug 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 236 Issued at 2200Z on 24 Aug 2002
IA.  Analysis of Solar Active Regions and Activity from  23/2100Z
to 24/2100Z:  Solar activity was high. An X3/1f flare occurred at
24/0112 UTC in Region 69. This region has rotated out of view beyond
the west solar limb near SW08. The flare was accompanied by Type
II/IV radio sweeps and discrete radio bursts that included 1200 sfu
output at 2695 MHz. Region 87 (S07E47) also produced an M1/1n flare
at 24/0548 UTC. Other regions of note include 83 (S18W27) and 85
(S09E03). Both produced flares today but without significant x-ray
output. New Region 89 (S16E62) rotated into view.
IB.  Solar Activity Forecast:  Solar activity is expected to be
moderate. M-class activity is possible in Regions 83, 85, and 87.
IIA.  Geophysical Activity Summary 23/2100Z to 24/2100Z:
The geomagnetic field was quiet to unsettled. A greater than 100 MeV
proton event began at 24/0130 UTC, reached a 29 pfu peak at 24/0210
UTC, and dropped below the 1 pfu event threshold at 24/1825 UTC. A
greater than 10 MeV proton event began at 24/0140 UTC, reached a 317
pfu peak at 24/0835 UTC, and remains in progress. The current proton
flux is about 200 pfu. These proton events are associated with the
X3 flare discussed in Part IA.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to become unsettled to active over the next day or two in
response to flare/CME activity of the past few days. The greater
than 10 MeV proton event is expected to continue in progress for the
next 24-48 hours.
III.  Event Probabilities 25 Aug-27 Aug
Class M    75/75/75
Class X    10/05/05
Proton     99/95/90
PCAF       in progress
IV.  Penticton 10.7 cm Flux
Observed           24 Aug 196
Predicted   25 Aug-27 Aug  190/185/180
90 Day Mean        24 Aug 170
V.  Geomagnetic A Indices
Observed Afr/Ap 23 Aug  006/011
Estimated Afr/Ap 24 Aug  012/015
Predicted Afr/Ap 25 Aug-27 Aug  015/020-015/020-015/020
VI.  Geomagnetic Activity Probabilities 25 Aug-27 Aug
A.  Middle Latitudes
Active                30/25/25
Minor storm           15/10/10
Major-severe storm    05/05/05
B.  High Latitudes
Active                50/40/40
Minor storm           20/15/15
Major-severe storm    05/05/05