:Product: 20040817RSGA.txt
:Issued: 2004 Aug 17 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 230 Issued at 2200Z on 17 Aug 2004
IA.  Analysis of Solar Active Regions and Activity from  16/2100Z
to 17/2100Z:  Solar activity has been moderate.  Region 656 (S14W77)
produced several major flares over the period.  The largest flare
was an M2.4 flare at 17/1937 UTC.  Region 656 decayed slightly as it
approached the west limb.  A large filament erupted in the southeast
quadrant of the solar disk at 0500 UTC, observed on SOHO/EIT
imagery.  Shortly thereafter a CME was observed emerging from the
southeast limb at 0630 UTC on LASCO imagery.  The CME was not
directed towards Earth.  No new regions were numbered today.
IB.  Solar Activity Forecast:  Solar activity is expected to be
moderate to high.  Region 656 may still produce major flare activity
before it crosses the west limb in the next day.
IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z:
Geomagnetic activity has been quiet to unsettled.  The greater than 2
MeV electron flux at geosynchronous orbit reached high levels today.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be quiet to unsettled all three days.  Isolated active
conditions are possible on day three (20 Aug) from the minor effects
of a small coronal hole that will reach geoeffective position.
III.  Event Probabilities 18 Aug-20 Aug
Class M    75/50/25
Class X    20/10/01
Proton     10/05/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           17 Aug 135
Predicted   18 Aug-20 Aug  125/115/115
90 Day Mean        17 Aug 109
V.  Geomagnetic A Indices
Observed Afr/Ap 16 Aug  005/008
Estimated Afr/Ap 17 Aug  008/009
Predicted Afr/Ap 18 Aug-20 Aug  008/008-005/008-008/015
VI.  Geomagnetic Activity Probabilities 18 Aug-20 Aug
A.  Middle Latitudes
Active                20/20/30
Minor storm           05/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                30/30/35
Minor storm           05/05/05
Major-severe storm    01/01/01