:Product: 20020320RSGA.txt
:Issued: 2002 Mar 20 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 079 Issued at 2200Z on 20 Mar 2002
IA.  Analysis of Solar Active Regions and Activity from  19/2100Z
to 20/2100Z:  Solar activity was low. A long-duration C4 flare began
at 1544 UTC and lasted until 1919 UTC. The corresponding source on
the disk was not entirely certain but it seemed most likely to be
correlated to activity observed in Region 9866 (S08W73). Additional
C-class subflares occurred during the day, with many of these coming
from Region 9875. Region 9875 showed steady growth during the past
24 hours. Three new region were assigned today: 9876 (S16E65), 9877
(N18W29), and 9878 (N08E75).
IB.  Solar Activity Forecast:  Solar activity is expected to be low
to moderate during the next three days.
IIA.  Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field was quiet until 1329 UTC when a sudden impulse
(SI) occurred. Since then the geomagnetic field has ranged from
quiet to active levels. The SI was caused by an interplanetary shock
which was seen at the ACE spacecraft at 1307 UTC. The disturbance is
most likely the result of the halo CME was observed in LASCO C2 at
18/0254 UTC. The shock also pushed the greater than 10 MeV proton
fluxes up to about 19 PFU at 1525 UTC. The proton event fluxes
dropped below event level at 1820 UTC.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be mostly unsettled for the next three days. There is a
chance for some isolated active levels on the second day as a
possible response to yesterday's partial halo CME.
III.  Event Probabilities 21 Mar-23 Mar
Class M    50/50/50
Class X    05/05/05
Proton     10/10/05
PCAF       yellow
IV.  Penticton 10.7 cm Flux
Observed           20 Mar 188
Predicted   21 Mar-23 Mar  175/170/165
90 Day Mean        20 Mar 213
V.  Geomagnetic A Indices
Observed Afr/Ap 19 Mar  015/017
Estimated Afr/Ap 20 Mar  010/010
Predicted Afr/Ap 21 Mar-23 Mar  010/010-015/015-010/008
VI.  Geomagnetic Activity Probabilities 21 Mar-23 Mar
A.  Middle Latitudes
Active                25/35/25
Minor storm           20/25/20
Major-severe storm    10/15/10
B.  High Latitudes
Active                25/35/25
Minor storm           20/25/20
Major-severe storm    10/15/10