:Product: 20040720RSGA.txt
:Issued: 2004 Jul 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 202 Issued at 2200Z on 20 Jul 2004
IA.  Analysis of Solar Active Regions and Activity from  19/2100Z
to 20/2100Z:  Solar activity increased to high levels today.  Region
652 (N10E32) produced an M8/3b major flare at 20/1232Z with an
associated Tenflare of 3000 sfu's.  A Type II radio sweep with an
estimated shock velocity of 485 km/s and a Type IV also accompanied
the flare.  The C6/Sf flare that occurred at 20/1126Z in conjunction
with the flare mentioned above produced what appears as a full halo
CME signature on LASCO C3 imagery.  The delta structure seen as the
dominate intermediate spot remains intact and the magnetic
classification continues to exhibit beta-gamma-delta properties. 
Region 652 continues to show growth in spot area which now exceeds
1600 millionths in white light.  Region 649 (S10W27) continues to
show decay and was limited to C-class flare activity today.  Delta
structures are evident in the leading polarity spot cluster while
yesterday's trailing polarity delta spot is no longer discernible. 
A significant and continued loss of spot area was again seen over
the past 24 hours.  No new regions were numbered today.
IB.  Solar Activity Forecast:  Solar activity is expected to be at
moderate to high levels.  Region 652 is capable of producing further
major flare activity.
IIA.  Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field was at quiet to unsettled levels.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at predominantly unsettled levels on 21 and 22 July. 
A shock passage from the combination of the C6 and M8 x-ray flares
today is expected to pass the ACE spacecraft early on 23 July.
III.  Event Probabilities 21 Jul-23 Jul
Class M    75/75/75
Class X    30/30/30
Proton     15/20/25
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           20 Jul 175
Predicted   21 Jul-23 Jul  180/175/170
90 Day Mean        20 Jul 098
V.  Geomagnetic A Indices
Observed Afr/Ap 19 Jul  011/009
Estimated Afr/Ap 20 Jul  008/008
Predicted Afr/Ap 21 Jul-23 Jul  008/008-010/012-025/025
VI.  Geomagnetic Activity Probabilities 21 Jul-23 Jul
A.  Middle Latitudes
Active                15/15/40
Minor storm           05/10/25
Major-severe storm    01/05/15
B.  High Latitudes
Active                15/20/45
Minor storm           05/15/25
Major-severe storm    01/05/15