:Product: 20040425RSGA.txt
:Issued: 2004 Apr 25 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 116 Issued at 2200Z on 25 Apr 2004
IA.  Analysis of Solar Active Regions and Activity from  24/2100Z
to 25/2100Z:  Solar activity was moderate. Region 599 (N16E28)
produced an M2/1N flare today at 0537 UTC, as well as a number of
smaller, C-class events. The group continued to grow today, and
shows some magnetic complexity, particularly just behind the large
leader spot where smaller spots of opposite polarity are in close
proximity. Most of the flare brightenings occurred along an
east-west inversion line in the mid-to-trailing portion of the
region. Region 536 (S08W36) is still the largest group on the disk,
but was quiet and appears to be slowly decaying.
IB.  Solar Activity Forecast:  Solar activity is expected to be
mostly low, but there is a fair chance for an additional, isolated
M-class event during the next three days from Region 599.
IIA.  Geophysical Activity Summary 24/2100Z to 25/2100Z:
The geomagnetic field was mostly unsettled. There was an isolated
active period at high latitudes from 0600-0900 UTC. Solar wind data
show continuation of a weak, high-speed stream, with velocities
ranging mostly between 500-550 km/s.
IIB.  Geophysical Activity Forecast:  The geomagnetic field should
persist at the current, mostly unsettled levels for the next 24-36
hours (26 April to partway through 27 April). A decrease is expected
to begin partway through the 2nd day (27 April) and quiet to
unsettled levels should prevail on the third day (28 April).
III.  Event Probabilities 26 Apr-28 Apr
Class M    35/35/35
Class X    05/05/05
Proton     05/05/05
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           25 Apr 107
Predicted   26 Apr-28 Apr  110/110/110
90 Day Mean        25 Apr 107
V.  Geomagnetic A Indices
Observed Afr/Ap 24 Apr  007/011
Estimated Afr/Ap 25 Apr  010/010
Predicted Afr/Ap 26 Apr-28 Apr  012/012-010/010-005/008
VI.  Geomagnetic Activity Probabilities 26 Apr-28 Apr
A.  Middle Latitudes
Active                25/20/15
Minor storm           20/15/10
Major-severe storm    10/05/05
B.  High Latitudes
Active                35/30/25
Minor storm           25/20/15
Major-severe storm    15/10/05