NOAA SEC Report of Solar-Geophysical Activity 17 Dec 2000

:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Dec 17 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 352 Issued at 2200Z on 17 Dec 2000
IA.  Analysis of Solar Active Regions and Activity from  16/2100Z
to 17/2100Z:  Solar activity has been low. Nearly all of today's
numerous C-class flares came from newly emerged Region 9276
(S12W72). The largest of these flares was a C5/Sf at 1840Z. The
region emerged from an area of little more than plage to a 130
millionths D-type sunspot group during the past 24 hours. Two
additional regions were assigned today: Region 9277 (N16W63) emerged
as a small H-type group, and Region 9278 (N09E67) rotated into view
as a simple H-type group.
IB.  Solar Activity Forecast:  Solar activity is expected to be
predominantly low for the next 72 hours, but there is a slight
chance for an isolated M-class event.
IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field was mostly quiet to unsettled, with one active
period from 1500-1800Z. The slight increase from yesterday's quiet
levels is most likely related to about 20 hours of sustained, weakly
negative values of the Z-component of the interplanetary magnetic
field.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be mostly quiet to unsettled during the next three days.
III.  Event Probabilities 18 Dec-20 Dec
Class M    30/30/30
Class X    01/01/01
Proton     01/01/01
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           17 Dec 197
Predicted   18 Dec-20 Dec  195/195/195
90 Day Mean        17 Dec 176
V.  Geomagnetic A Indices
Observed Afr/Ap 16 Dec  004/004
Estimated Afr/Ap 17 Dec  011/010
Predicted Afr/Ap 18 Dec-20 Dec  010/010-005/010-005/010
VI.  Geomagnetic Activity Probabilities 18 Dec-20 Dec
A.  Middle Latitudes
Active                25/20/20
Minor storm           10/10/10
Major-severe storm    05/01/01
B.  High Latitudes
Active                25/20/20
Minor storm           10/10/10
Major-severe storm    05/01/01