:Product: 0426RSGA.txt
:Issued: 2008 Apr 26 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 117 Issued at 2200Z on 26 Apr 2008
IA.  Analysis of Solar Active Regions and Activity from  25/2100Z
to 26/2100Z:  Solar  activity was very low. The solar disk is void of
spots. Nonetheless there was a B3/Sf flare at 1408Z from an
unnumbered area of spotless plage near N08E09. The flare was
associated with a wave that was visible in EUV imagery on STEREO and
SOHO, type II and type IV radio sweeps, as well as a slow, faint,
full halo CME visible in coronagraph imagery. The estimated plane of
sky speed for the CME was around 430-480 km/s.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low.
IIA.  Geophysical Activity Summary 25/2100Z to 26/2100Z:
The geomagnetic field was quiet to unsettled during the past 24
hours. Solar wind speed remains somewhat elevated (around 460-500 
km/s) and density very low (around 1 p/cc), consistent with the
decaying phase of a high speed stream. The greater than 2 MeV
electron flux at geosynchronous orbit was high during the past 24
hours.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be predominantly quiet for the next two days (27-28
April). A small increase is expected late on the third day (29
April) in response to today's CME event: activity is expected to be
unsettled with a chance for isolated active periods after the
disturbance arrives.
III.  Event Probabilities 27 Apr-29 Apr
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       Green
IV.  Penticton 10.7 cm Flux
Observed           26 Apr 069
Predicted   27 Apr-29 Apr  070/070/070
90 Day Mean        26 Apr 071
V.  Geomagnetic A Indices
Observed Afr/Ap 25 Apr  007/008
Estimated Afr/Ap 26 Apr  007/008
Predicted Afr/Ap 27 Apr-29 Apr  005/005-005/005-007/008
VI.  Geomagnetic Activity Probabilities 27 Apr-29 Apr
A.  Middle Latitudes
Active                10/10/20
Minor storm           05/05/10
Major-severe storm    01/01/01
B.  High Latitudes
Active                10/10/25
Minor storm           05/05/10
Major-severe storm    01/01/05