:Product: 20030418RSGA.txt
:Issued: 2003 Apr 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 108 Issued at 2200Z on 18 Apr 2003
IA.  Analysis of Solar Active Regions and Activity from  17/2100Z
to 18/2100Z:  Solar activity has been at moderate levels.  There were
several minor C-class events during the last 24 hours with a single
M1.1 from Region 337 (S12E74) at 1958 UTC.  A 13 degree disappearing
solar filament was observed early in the period near Region 335
(S25E21).  There was a small coronal mass ejection associated with
that filament, but it was not earth-directed.
IB.  Solar Activity Forecast:  Solar activity is expected to be at
low to moderate levels for the entire period.  Region 337 (S12E74)
is just coming on to the visible disk, and appears in solar x-ray
imagery to be a potentially active region.
IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field was at unsettled to active levels with an
isolated quiet period from 0300 UTC to 0600 UTC.  The coronal hole
induced high speed solar wind stream continues.  The greater than 2
MeV electron fluxes at geo-synchronous orbit reached high levels
today.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at mostly unsettled levels as the current disturbance
continues to transition out of geoeffective range.  Continued
unsettled levels are expected through day two, with a further
decrease to mostly quiet levels on day three.
III.  Event Probabilities 19 Apr-21 Apr
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           18 Apr 108
Predicted   19 Apr-21 Apr  110/110/115
90 Day Mean        18 Apr 127
V.  Geomagnetic A Indices
Observed Afr/Ap 17 Apr  020/030
Estimated Afr/Ap 18 Apr  018/019
Predicted Afr/Ap 19 Apr-21 Apr  012/015-010/012-007/010
VI.  Geomagnetic Activity Probabilities 19 Apr-21 Apr
A.  Middle Latitudes
Active                35/30/30
Minor storm           25/15/15
Major-severe storm    05/05/05
B.  High Latitudes
Active                35/30/30
Minor storm           30/25/20
Major-severe storm    20/10/10