:Product: 20030417RSGA.txt
:Issued: 2003 Apr 17 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 107 Issued at 2200Z on 17 Apr 2003
IA.  Analysis of Solar Active Regions and Activity from  16/2100Z
to 17/2100Z:  Solar activity has been very low. There was a single
minor B-class event during the past 24 hours. A new Region 336
(N12E75) was numbered today.  All spotted regions on the disk
continue to be small, quiet, and stable.  There has been a slow
increase in background levels due to the arrival of the new region.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low to low. The background levels are likely to continue to increase
slightly with the addition of regions which are now visible in GOES
Solar x-ray imagery behind East limb at N20 and S25.
IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field was mostly unsettled to active during the past
24 hours with a minor storm period from 0300-0900 UTC in the mid
latitudes, and a minor storm period at high latitudes from both
0300-1200 UTC and 1500-1800 UTC. The coronal-hole induced high speed
solar wind flow continues. The greater than 2 MeV electron fluxes
reached high levels today.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be mostly active but decreasing to unsettled within the
next 24 hours as the current disturbance transitions out of
geoeffective range. Continued unsettled levels are expected for days
two and three.
III.  Event Probabilities 18 Apr-20 Apr
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           17 Apr 101
Predicted   18 Apr-20 Apr  100/100/105
90 Day Mean        17 Apr 127
V.  Geomagnetic A Indices
Observed Afr/Ap 16 Apr  013/031
Estimated Afr/Ap 17 Apr  029/033
Predicted Afr/Ap 18 Apr-20 Apr  015/020-012/015-010/012
VI.  Geomagnetic Activity Probabilities 18 Apr-20 Apr
A.  Middle Latitudes
Active                40/35/30
Minor storm           30/25/15
Major-severe storm    05/05/05
B.  High Latitudes
Active                30/30/30
Minor storm           30/25/20
Major-severe storm    20/10/10