:Product: 20030527RSGA.txt
:Issued: 2003 May 27 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 147 Issued at 2200Z on 27 May 2003
IA.  Analysis of Solar Active Regions and Activity from  26/2100Z
to 27/2100Z:  Solar activity was at moderate levels.  Region 365
(S07W19) produced two M-class events the largest of which was a long
duration M1.6/1f at 0626Z.  Region 365 has shown rapid growth since
yesterday nearly doubling in area coverage.  Mixing polarities are
evident in the leader spots forming a beta-gamma-delta
configuration.  Analysis of LASCO imagery indicates a slow halo CME
associated with the M1 flare from 26/1637Z and a faster halo CME
associated with the M1.6 flare mentioned above.  Estimated plane of
sky speed for the fast CME was 700 km/s.  Three new regions were
numbered today:  Region 371 (S13W10), Region 372 (S14W03), and
Region 373 (N08E81).
IB.  Solar Activity Forecast:  Solar activity is expected to be at
low to moderate levels.  Region 365 is expected to produce C-class
flare and isolated M-class events.
IIA.  Geophysical Activity Summary 26/2100Z to 27/2100Z:
The geomagnetic field was at unsettled to active levels.  Elevated
solar wind speed near 500 km/s resulted in a disturbed geomagnetic
field.  The greater than 2 MeV electron flux at geosynchronous orbit
reached high levels.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at unsettled to minor storm levels.  A coronal hole
high speed flow is expected on day one of the period.  Weak CME
shock effects are possible on day two and day three of the period.
III.  Event Probabilities 28 May-30 May
Class M    20/25/25
Class X    05/05/05
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           27 May 129
Predicted   28 May-30 May  135/140/140
90 Day Mean        27 May 125
V.  Geomagnetic A Indices
Observed Afr/Ap 26 May  013/018
Estimated Afr/Ap 27 May  020/022
Predicted Afr/Ap 28 May-30 May  020/025-015/015-015/015
VI.  Geomagnetic Activity Probabilities 28 May-30 May
A.  Middle Latitudes
Active                40/35/30
Minor storm           20/15/10
Major-severe storm    10/05/05
B.  High Latitudes
Active                45/35/35
Minor storm           25/20/20
Major-severe storm    10/05/05