NOAA SEC Report of Solar-Geophysical Activity 15 Dec 2001

:Product: Report of Solar-Geophysical Activity
:Issued: 2001 Dec 15 2200 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 349 Issued at 2200Z on 15 Dec 2001
IA.  Analysis of Solar Active Regions and Activity from  14/2100Z
to 15/2100Z:  Solar activity decreased to low levels. There were two
large, magnetically complex sunspot groups on the visible disk:
Region 9727 (S22W88) and Region 9733 (N14W23). Region 9727 produced
isolated subflares while crossing the west limb. It retained at
least a moderate degree of magnetic complexity as it rotated out of
view with mixed polarities in its trailer spots. Region 9733
remained the most active region on the disk as it produced
occasional subflares, some of which reached C-class. This region has
showed a gradual decrease in area since 13 December. However,
opposite-polarity magnetic flux has gradually emerged within its
northernmost spots during the last two days where a possible delta
magnetic configuration may reside. The remaining active regions
showed minor changes during the period. New Region 9742 (N09E73)
rotated into view during the period.
IB.  Solar Activity Forecast:  Solar activity is expected to be at
moderate to high levels. Isolated low-level M-class flares are
expected. There will also be a chance for a major flare from Region
9733. Region 9727 could also produce a major flare during the first
day of the period as it completes its west limb passage.
IIA.  Geophysical Activity Summary 14/2100Z to 15/2100Z:
Geomagnetic field activity was at quiet to unsettled levels.
IIB.  Geophysical Activity Forecast:  Unsettled to minor storm
conditions may occur on 16 - 17 December due to a possible CME
passage (associated with the X6/3b flare of 13 December). Activity
is expected to decrease to quiet to unsettled levels during the
latter half of the forecast period. There will be a chance for a
proton flare from Region 9733.
III.  Event Probabilities 16 Dec-18 Dec
Class M    80/75/75
Class X    20/15/15
Proton     20/15/15
PCAF       yellow
IV.  Penticton 10.7 cm Flux
Observed           15 Dec 218
Predicted   16 Dec-18 Dec  205/195/190
90 Day Mean        15 Dec 218
V.  Geomagnetic A Indices
Observed Afr/Ap 14 Dec  004/004
Estimated Afr/Ap 15 Dec  013/012
Predicted Afr/Ap 16 Dec-18 Dec  015/020-015/015-010/010
VI.  Geomagnetic Activity Probabilities 16 Dec-18 Dec
A.  Middle Latitudes
Active                35/30/25
Minor storm           15/10/05
Major-severe storm    05/01/01
B.  High Latitudes
Active                40/35/30
Minor storm           20/15/05
Major-severe storm    10/05/01