NOAA SEC Report of Solar-Geophysical Activity 27 Dec 2001

:Product: Report of Solar-Geophysical Activity
:Issued: 2001 Dec 27 2210 UT
# 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 361 Issued at 2200Z on 27 Dec 2001
IA.  Analysis of Solar Active Regions and Activity from  26/2100Z
to 27/2100Z:  Solar activity has been high, due to the occurrence of
five M-class flares.  Region 9748 (S11W64) produced two M-class
events, the largest being an M2/2n at 27/1648 UTC.  Lesser M-class
activity included one uncorrelated event, and flares from Region
9742 (N12W81), and from the spotless plage of Region 9752 (S13W85)
near the west limb.  Two new regions were numbered:  9762 (N03E07)
and 9763 (N06E76).
IB.  Solar Activity Forecast:  Solar activity is expected to be
moderate to high for the next three days.
IIA.  Geophysical Activity Summary 26/2100Z to 27/2100Z:
The geomagnetic field was at quiet to unsettled levels.  The 10 MeV
proton event, which began on 26 December, remains in progress with
current flux levels at about 25 pfu.
IIB.  Geophysical Activity Forecast:  Geomagnetic field activity is
expected to increase within the next 24 hours, due to a possible
flanking shock passage from the CME activity of 26 December.  Minor
storm conditions, with isolated major storm periods at higher
latitudes are possible during the first day of the forecast period. 
Storm activity is expected to be of relatively brief duration, with
predominantly quiet to unsettled conditions expected for days two
and three of the forecast period.  The solar proton event in
progress is expected to wane over the next 24-36 hours.
III.  Event Probabilities 28 Dec-30 Dec
Class M    80/80/80
Class X    10/10/10
Proton     75/25/10
PCAF       yellow
IV.  Penticton 10.7 cm Flux
Observed           27 Dec 275
Predicted   28 Dec-30 Dec  265/260/255
90 Day Mean        27 Dec 217
V.  Geomagnetic A Indices
Observed Afr/Ap 26 Dec  010/007
Estimated Afr/Ap 27 Dec  009/007
Predicted Afr/Ap 28 Dec-30 Dec  030/030-018/015-008/010
VI.  Geomagnetic Activity Probabilities 28 Dec-30 Dec
A.  Middle Latitudes
Active                30/20/15
Minor storm           20/05/05
Major-severe storm    05/01/01
B.  High Latitudes
Active                35/25/15
Minor storm           25/10/05
Major-severe storm    10/01/01