:Product: 1221RSGA.txt
:Issued: 2006 Dec 21 2204 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 355 Issued at 2200Z on 21 Dec 2006
IA.  Analysis of Solar Active Regions and Activity from  20/2100Z
to 21/2100Z:  Solar activity continues at very low levels. There are
currently no sunspots on the visible disk.
IB.  Solar Activity Forecast:  Solar activity is expected to continue
at very low levels. Old Region 926 (S09, L=138) is due to return to
the visible disk tomorrow, and may slightly increase activity
levels.
IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z:
The geomagnetic field was at quiet to active levels, with isolated
minor storm periods at high latitudes. A high speed coronal hole
stream is responsible for the disturbed periods. Solar wind speed is
in slow decline and ended the period near 600 km/s. The greater than
2 MeV electrons at geosynchronous orbit were at high levels again
today.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be quiet to active on 22 and 23 December, with isolated
minor storm periods at higher latitudes. Quiet to unsettled levels
with isolated active periods are expected on 24 December.
III.  Event Probabilities 22 Dec-24 Dec
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           21 Dec 072
Predicted   22 Dec-24 Dec  075/080/080
90 Day Mean        21 Dec 081
V.  Geomagnetic A Indices
Observed Afr/Ap 20 Dec  016/024
Estimated Afr/Ap 21 Dec  015/018
Predicted Afr/Ap 22 Dec-24 Dec  012/015-010/015-008/010
VI.  Geomagnetic Activity Probabilities 22 Dec-24 Dec
A.  Middle Latitudes
Active                30/25/20
Minor storm           15/10/05
Major-severe storm    05/01/01
B.  High Latitudes
Active                40/35/25
Minor storm           20/15/05
Major-severe storm    05/05/01