:Product: 1218RSGA.txt
:Issued: 2007 Dec 18 2203 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Weather Prediction Center and the U.S. Air Force.
#
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 352 Issued at 2200Z on 18 Dec 2007
IA.  Analysis of Solar Active Regions and Activity from  17/2100Z
to 18/2100Z:  Solar activity was at low levels.  Region 978 (S08W91)
has produced several C-class events, the largest being a C2 at
18/1320Z.
IB.  Solar Activity Forecast:  Solar activity is expected to be at
very low to low levels.  Activity levels should decrease with the
rotation of Region 978 beyond the west limb.
IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z:
The geomagnetic field was at predominately unsettled to active
levels.  This elevated activity is due to a coronal hole high speed
stream that has rotated into a geoeffective position.  Measurements
at the ACE spacecraft indicated a steady increase in solar wind
speed.  At the time of forecast issue the wind speed was
approximately 700 km/s.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at mostly unsettled to active levels for 19 to 21
December due to the continued influence of the high speed stream.
III.  Event Probabilities 19 Dec-21 Dec
Class M    05/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       Green
IV.  Penticton 10.7 cm Flux
Observed           18 Dec 077
Predicted   19 Dec-21 Dec  070/070/070
90 Day Mean        18 Dec 071
V.  Geomagnetic A Indices
Observed Afr/Ap 17 Dec  012/017
Estimated Afr/Ap 18 Dec  015/020
Predicted Afr/Ap 19 Dec-21 Dec  015/015-015/015-012/012
VI.  Geomagnetic Activity Probabilities 19 Dec-21 Dec
A.  Middle Latitudes
Active                50/50/40
Minor storm           20/20/15
Major-severe storm    05/05/05
B.  High Latitudes
Active                50/50/40
Minor storm           25/25/20
Major-severe storm    10/10/05