:Product: 20021228RSGA.txt
:Issued: 2002 Dec 28 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 362 Issued at 2200Z on 28 Dec 2002
IA.  Analysis of Solar Active Regions and Activity from  27/2100Z
to 28/2100Z:  Solar activity was very low. The now spotless Region
235 (N13W08) produced a subfaint flare early in the period, but has
been quiet since. Occasional intensity enhancements accompanied a
small increase in the size and complexity of Region 236 (N16W41).
New Regions 237 (S26E00) and 238 (N09E15) were numbered today. The
remaining regions are small, showing no significant changes this
period. There are several large, but mostly quiescent filaments on
the visible disk. Occasional motion was noted in the large filament
centered near N22W12. A long duration, but low intensity X-ray
enhancement was observed beginning at around 28/1700Z. This was
likely associated with a strong CME that appears to have originated
behind the NW limb.
IB.  Solar Activity Forecast:  Solar activity is expected to be low
to very low. There's a chance for low C-class activity from Regions
234 (N19E19) and 236.
IIA.  Geophysical Activity Summary 27/2100Z to 28/2100Z:
The geomagnetic field was mostly unsettled to active at all
latitudes. A high speed stream, associated with a large equatorial
coronal hole, began late on 26 Dec and continues to buffet the
magnetic field. The peak solar wind in this high speed stream
exceeded 750 km/s, but has declined slowly to near 650 km/s by the
end of the period. The greater than 2 MeV electron fluxes at
geosynchronous orbit reached high levels.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at quiet to active levels. The high speed coronal hole
stream currently impacting the geomagnetic field will gradually
subside through day one. Ejecta from the CME off the NW limb late in
the period today does not appear Earthbound. Expect mostly unsettled
levels through days two and three of the period.
III.  Event Probabilities 29 Dec-31 Dec
Class M    10/10/10
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           28 Dec 117
Predicted   29 Dec-31 Dec  115/115/120
90 Day Mean        28 Dec 166
V.  Geomagnetic A Indices
Observed Afr/Ap 27 Dec  022/037
Estimated Afr/Ap 28 Dec  020/020
Predicted Afr/Ap 29 Dec-31 Dec  015/015-008/010-008/010
VI.  Geomagnetic Activity Probabilities 29 Dec-31 Dec
A.  Middle Latitudes
Active                50/30/20
Minor storm           20/10/05
Major-severe storm    05/01/01
B.  High Latitudes
Active                60/40/30
Minor storm           30/15/05
Major-severe storm    10/01/01