:Product: 20030818RSGA.txt
:Issued: 2003 Aug 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 230 Issued at 2200Z on 18 Aug 2003
IA.  Analysis of Solar Active Regions and Activity from  17/2100Z
to 18/2100Z:  Activity was at low levels.  Region 431 (S10W52)
produced a C2/Sf flare at 18/0906Z as it continues to decay. Region
436 (N08E57) rotated further onto the visible disk revealing 160
millionths in area coverage and a beta magnetic configuration.
IB.  Solar Activity Forecast:  Activity is expected to be a low
levels.  There is a slight chance of an isolated M-class event from
Region 431 or Region 436.
IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field was at active to severe storm levels.  Around
18/0100Z the Bz component of the interplanetary magnetic field
turned southward to -15 nT with a peak near -25 nT.  This shift in
Bz resulted in sustained minor to severe storm levels until
18/1500Z.  Solar wind data are consistent with an interplanetary
transient.  Re-analysis of solar data for the past few days indicate
activity in Region 431 (near center disk) late on 14 August as a
possible source of this storm.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to range from quiet to minor storm levels.  Geomagnetic
storming is expected diminish on day one with isolated minor storm
levels possible.  Quiet to unsettled conditions are expected on day
two and day three of the period.
III.  Event Probabilities 19 Aug-21 Aug
Class M    30/25/25
Class X    05/05/05
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           18 Aug 116
Predicted   19 Aug-21 Aug  115/115/110
90 Day Mean        18 Aug 127
V.  Geomagnetic A Indices
Observed Afr/Ap 17 Aug  010/015
Estimated Afr/Ap 18 Aug  062/082
Predicted Afr/Ap 19 Aug-21 Aug  020/025-015/015-015/015
VI.  Geomagnetic Activity Probabilities 19 Aug-21 Aug
A.  Middle Latitudes
Active                40/20/20
Minor storm           25/05/05
Major-severe storm    10/01/01
B.  High Latitudes
Active                50/25/25
Minor storm           30/10/10
Major-severe storm    15/01/01