:Product: 20030518RSGA.txt
:Issued: 2003 May 18 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 138 Issued at 2200Z on 18 May 2003
IA.  Analysis of Solar Active Regions and Activity from  17/2100Z
to 18/2100Z:  Solar activity was low. Region 357 (S16W20) produced
the only C-class flare of the period - a C1 flare at 18/1057Z. This
region has shown little change over the past 24 hours, maintaining a
simple beta configuration. Region 362 (S11E37) appeared to develop
some complexity early in the period, but has since stabilized. New
Region 363 (S08W04) was numbered today.
IB.  Solar Activity Forecast:  Solar activity is expected to continue
at low levels. Regions 357 and 362 have potential for low C-class
activity. Activity is expected to increase later in the week with
the return of a zone of active longitudes that contained old Regions
345 (S17, L=167), 348 (S35, L=149), and 349 (S14, L=153).
IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field was quiet to unsettled. Slightly enhanced solar
wind conditions occurred late in the period and produced the
unsettled conditions. The greater than 2 MeV electrons at
geosynchronous orbit reached very high levels today.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to range from quiet to active. Increased solar wind speed,
associated with a favorably positioned coronal hole will cause
occasional disturbed periods through day two.
III.  Event Probabilities 19 May-21 May
Class M    10/10/10
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           18 May 109
Predicted   19 May-21 May  115/120/130
90 Day Mean        18 May 124
V.  Geomagnetic A Indices
Observed Afr/Ap 17 May  006/009
Estimated Afr/Ap 18 May  007/009
Predicted Afr/Ap 19 May-21 May  015/015-012/012-010/010
VI.  Geomagnetic Activity Probabilities 19 May-21 May
A.  Middle Latitudes
Active                30/25/20
Minor storm           10/10/05
Major-severe storm    05/05/05
B.  High Latitudes
Active                40/35/30
Minor storm           20/15/15
Major-severe storm    10/05/05