:Product: 20031220RSGA.txt
:Issued: 2003 Dec 20 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 354 Issued at 2200Z on 20 Dec 2003
IA.  Analysis of Solar Active Regions and Activity from  19/2100Z
to 20/2100Z:  Solar activity has been low.  Region 525 (N09E17)
produced several C-class flares, including a C2.6/Sf at 20/0016Z.
New Region 529 (SN47) at N09W18 was numbered today.
IB.  Solar Activity Forecast:  Solar activity is expected to be low
to moderate.  Regions 525 and 528 (N09E49) are expected to produce
C-class flares, and are capable of producing isolated M-class
flares.
IIA.  Geophysical Activity Summary 19/2100Z to 20/2100Z:
The geomagnetic field has been at quiet to major storm levels.
Increased solar wind speed was observed by the ACE spacecraft at
20/0000Z.  Wind speed increased from just over 300 km/s to 500 km/s
as of this writing, due most likely to a coronal hole moving into
geoeffective position.  The greater than 2 MeV electron flux at
geosynchronous orbit began the period at high levels, but has been
cycling above and below the high threshold level since the arrival
of increased solar wind speed.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be quiet to active, with isolated minor storm conditions
on 21-22 December due to persistent effects from the geoeffective
coronal hole.
III.  Event Probabilities 21 Dec-23 Dec
Class M    25/25/25
Class X    05/05/05
Proton     01/01/01
PCAF       Green
IV.  Penticton 10.7 cm Flux
Observed           20 Dec 130
Predicted   21 Dec-23 Dec  130/135/140
90 Day Mean        20 Dec 135
V.  Geomagnetic A Indices
Observed Afr/Ap 19 Dec  001/007
Estimated Afr/Ap 20 Dec  012/018
Predicted Afr/Ap 21 Dec-23 Dec  015/020-010/015-010/010
VI.  Geomagnetic Activity Probabilities 21 Dec-23 Dec
A.  Middle Latitudes
Active                35/30/30
Minor storm           20/15/10
Major-severe storm    05/05/01
B.  High Latitudes
Active                45/40/40
Minor storm           25/25/20
Major-severe storm    10/10/05