:Product: 20041217RSGA.txt
:Issued: 2004 Dec 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 352 Issued at 2200Z on 17 Dec 2004
IA.  Analysis of Solar Active Regions and Activity from  16/2100Z
to 17/2100Z:  Solar activity was very low.  Region 710 (S07W72) has
shown a slight increase in area and spot number, but remains quiet. 
New regions 712 (S10E50) and 713 (S10E70) were numbered today.
IB.  Solar Activity Forecast:  Solar activity is expected to be very
low to low.  There is a chance for a C-class flare from the new
regions near the southeast limb.
IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field was at quiet to active levels with a period of
minor storming between 17/0300Z and 17/0600Z.  The active to minor
storm levels were due to the continued influence of a geoeffective
coronal hole high speed stream.  There was an increase in the solar
wind speed at ACE from approximately 550 km/s to 650 km/s during the
reporting period.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be quiet to active with minor storm periods possible at
high latitudes on 18 December.  Expect quiet to unsettled with
isolated active conditions on 19 December as the high speed coronal
hole stream subsides.  Expect quiet to unsettled levels on 20
December.
III.  Event Probabilities 18 Dec-20 Dec
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       Green
IV.  Penticton 10.7 cm Flux
Observed           17 Dec 090
Predicted   18 Dec-20 Dec  090/090/095
90 Day Mean        17 Dec 104
V.  Geomagnetic A Indices
Observed Afr/Ap 16 Dec  008/010
Estimated Afr/Ap 17 Dec  014/020
Predicted Afr/Ap 18 Dec-20 Dec  008/015-006/008-004/005
VI.  Geomagnetic Activity Probabilities 18 Dec-20 Dec
A.  Middle Latitudes
Active                20/15/10
Minor storm           10/10/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                25/20/15
Minor storm           15/10/10
Major-severe storm    05/05/01