:Product: 20020927RSGA.txt
:Issued: 2002 Sep 27 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 270 Issued at 2200Z on 27 Sep 2002
IA.  Analysis of Solar Active Regions and Activity from  26/2100Z
to 27/2100Z:  Solar activity was moderate during the past 24 hours.
Region 134 (N11E38) showed a marked increase in flare productivity
during the past 24 hours, including two M-class events. The first
was an M1/Sf at 1312 UTC and the second was an M1/Sf at 1942 UTC.
Coronagraph data show a relatively narrow CME off the northeast limb
in association with the first M-class event. Insufficient data were
available at forecast issue time to make any CME association with
the second M-class event. Analysis of the Region 134 shows the
development of a small delta configuration along an east-west
inversion line, and observations indicate the build up of magnetic
shear in this part of the region. The only other flare-producing
region on the disk was Region 132 (N19W65), which managed to produce
a couple C-class subflares, but appeared to be in a state of
decline. New Region 135 (S26E06) emerged on the disk today as a
simple D-type sunspot group.
IB.  Solar Activity Forecast:  Solar activity is expected to be low
to moderate. There is a fair chance for additional M-class events
from Region 134, and there is a slight chance that Region 132 may
produce an isolated M-class event as well.
IIA.  Geophysical Activity Summary 26/2100Z to 27/2100Z:
The geomagnetic field has been quiet to unsettled during the past 24
hours.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be quiet to unsettled for the next 24-36 hours. An
increase to unsettled to slightly active is expected late on the
second day and should last through the third day in response to a
favorably positioned coronal hole.
III.  Event Probabilities 28 Sep-30 Sep
Class M    50/50/50
Class X    05/05/05
Proton     05/05/05
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           27 Sep 152
Predicted   28 Sep-30 Sep  150/145/140
90 Day Mean        27 Sep 179
V.  Geomagnetic A Indices
Observed Afr/Ap 26 Sep  003/008
Estimated Afr/Ap 27 Sep  005/008
Predicted Afr/Ap 28 Sep-30 Sep  005/008-010/012-015/015
VI.  Geomagnetic Activity Probabilities 28 Sep-30 Sep
A.  Middle Latitudes
Active                15/35/35
Minor storm           10/15/20
Major-severe storm    05/05/10
B.  High Latitudes
Active                20/30/40
Minor storm           15/20/25
Major-severe storm    05/15/20