:Product: 0423RSGA.txt
:Issued: 2008 Apr 23 2203 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Weather Prediction Center and the U.S. Air Force.
#
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 114 Issued at 2200Z on 23 Apr 2008
IA.  Analysis of Solar Active Regions and Activity from  22/2100Z
to 23/2100Z:  Solar activity was very low. No flares occurred during
the past 24 hours. Region 992 (N13W17) has been quiet and stable and
is a small, simple C-type sunspot group.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low.
IIA.  Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field was initially unsettled but after 0300Z
increased to predominantly active levels. In addition there were two
minor storm periods; the first from 0600-0900Z and the second from
1500-1800Z. ACE real-time solar wind data show a slow increase in
solar wind speeds at the beginning of the period followed by a
marked increase in speed and temperature around 0400Z. The magnetic
field observations at ACE also indicate a gradual increase as well
as an extended period of mostly southward Bz from 0200Z to about
1700Z. The signatures are consistent with a co-rotating interaction
region followed by a high speed solar wind stream. Solar wind speed
remains elevated with values around 640 km/s at forecast issue time.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be unsettled to active with a chance for isolated minor
storm periods for the first day (24 April) as the high speed stream
persists. Activity is expected to decline to predominantly unsettled
for the second day (25 April) and to predominantly quiet for the
third data (26 April).
III.  Event Probabilities 24 Apr-26 Apr
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       Green
IV.  Penticton 10.7 cm Flux
Observed           23 Apr 071
Predicted   24 Apr-26 Apr  070/070/070
90 Day Mean        23 Apr 072
V.  Geomagnetic A Indices
Observed Afr/Ap 22 Apr  004/005
Estimated Afr/Ap 23 Apr  020/020
Predicted Afr/Ap 24 Apr-26 Apr  015/015-010/012-005/005
VI.  Geomagnetic Activity Probabilities 24 Apr-26 Apr
A.  Middle Latitudes
Active                45/35/10
Minor storm           20/10/05
Major-severe storm    10/05/01
B.  High Latitudes
Active                35/30/10
Minor storm           30/20/05
Major-severe storm    20/10/01