:Product: 0427RSGA.txt
:Issued: 2007 Apr 27 2203 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 117 Issued at 2200Z on 27 Apr 2007
IA.  Analysis of Solar Active Regions and Activity from  26/2100Z
to 27/2100Z:  Solar activity was very low during the past 24 hours.
Region 953 (S10E49) produced several B-class events during the past
24 hours. As the region has rotated more fully into view, it now
appears that the group consists mostly of a large penumbral area
which contains opposite magnetic polarities, making the group a
beta-delta magnetic classification.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low to low for the next three days (28-30 April), with a slight
chance for an isolated M-class event from Region 953.
IIA.  Geophysical Activity Summary 26/2100Z to 27/2100Z:
The geomagnetic field was quiet to active during the past 24 hours.
An initially quiet to unsettled field became unsettled to active
with the onset of a high speed solar wind stream around 1500Z. Solar
wind velocity increased to about 600 km/s and the interplanetary
magnetic field showed fluctuations from about -9 nT to +7 nT.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be mostly active with a chance for isolated minor storm
periods for the next 24 hours (28 April) as the high speed stream is
expected to continue. Unsettled levels with a chance for active
periods is expected for the second day (29 April) and conditions
should decline to mostly unsettled by the third day (30 April).
III.  Event Probabilities 28 Apr-30 Apr
Class M    15/15/15
Class X    01/01/01
Proton     01/01/01
PCAF       Green
IV.  Penticton 10.7 cm Flux
Observed           27 Apr 083
Predicted   28 Apr-30 Apr  085/085/085
90 Day Mean        27 Apr 074
V.  Geomagnetic A Indices
Observed Afr/Ap 26 Apr  004/006
Estimated Afr/Ap 27 Apr  008/012
Predicted Afr/Ap 28 Apr-30 Apr  020/030-015/015-010/010
VI.  Geomagnetic Activity Probabilities 28 Apr-30 Apr
A.  Middle Latitudes
Active                45/30/15
Minor storm           25/15/05
Major-severe storm    10/05/01
B.  High Latitudes
Active                45/30/20
Minor storm           30/20/15
Major-severe storm    15/10/05