:Product: 20030426RSGA.txt
:Issued: 2003 Apr 26 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 26 Apr 2003
IA.  Analysis of Solar Active Regions and Activity from  25/2100Z
to 26/2100Z:  Solar activity increased to high levels.  An abundance
of activity was observed today, most of which occurred in Region 338
(N18W71).  Region 338 produced a very impulsive M7.0 x-ray flare at
26/0807Z. This region also produced an M2.1/1f flare at 26/0058Z and
an M2.1/Sn flare at 26/0306Z along with multiple C-class events.
The delta magnetic complex remains intact and penumbral coverage
appears to be oscillating with this regions flare production.
Region 344 (N16E13) has yet to produce any flare activity although
the white-light penumbral coverage and the magnetic complexity of
this region have shown rapid growth during the past 24 hours.
Yesterday, this region was a simple beta complex which has since
developed into a beta-gamma-delta magnetic structure.  Region 337
(S14W26) was quiescent through most of the period.  Regions 347
(S20E36), 348 (S36E58), and 349 (S14E60) were newly numbered today.
IB.  Solar Activity Forecast:  Activity is expected to be at moderate
levels.  Region 338 remains capable of producing an isolated major
flare.
IIA.  Geophysical Activity Summary 25/2100Z to 26/2100Z:
The geomagnetic field was at quiet to active levels.  Influences from
yesterdays favorably positioned coronal hole have waned as the solar
wind speed has dropped to approximately 400 km/s.  The greater than
2 MeV electron fluxes reached high levels today.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at unsettled to active levels.  Minor storm
conditions are possible with the onset of a favorably positioned
coronal hole on days one and two.  Elevated field levels are
possible through the interval due to weak transient passages
resulting from the flare activity of the past several days.
III.  Event Probabilities 27 Apr-29 Apr
Class M    70/70/50
Class X    15/15/05
Proton     05/05/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           26 Apr 144
Predicted   27 Apr-29 Apr  150/145/140
90 Day Mean        26 Apr 126
V.  Geomagnetic A Indices
Observed Afr/Ap 25 Apr  019/032
Estimated Afr/Ap 26 Apr  010/015
Predicted Afr/Ap 27 Apr-29 Apr  020/025-015/020-012/015
VI.  Geomagnetic Activity Probabilities 27 Apr-29 Apr
A.  Middle Latitudes
Active                35/30/25
Minor storm           20/15/15
Major-severe storm    10/05/05
B.  High Latitudes
Active                40/35/30
Minor storm           30/20/10
Major-severe storm    15/10/05