NOAA SEC Report of Solar-Geophysical Activity 31 Dec 2001
:Product: Report of Solar-Geophysical Activity
:Issued: 2001 Dec 31 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 365 Issued at 2200Z on 31 Dec 2001
IA. Analysis of Solar Active Regions and Activity from 30/2100Z
to 31/2100Z: Solar activity was at low levels. Region 9754 (S08W42)
produced the largest flare of the period, an impulsive C6/1f flare
at 31/1845 UTC. Region 9767 (S23E60) was the only other source of
optically correlated flare activity during the period, producing
small C-class flares. This region appears to have fully rotated
onto the visible disk doubling reported arial spot coverage from
yesterday's analysis. Other regions on the disk were mostly placid
throughout the period.
IB. Solar Activity Forecast: Solar activity is expected to be at
moderate levels. Regions 9767, 9754, and 9751 (S08W42) all have the
potential to produce M-class flares.
IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z:
The geomagnetic field was at quiet to unsettled levels. The greater
than 10 MeV proton event that began on 30/0245 UTC remains in
progress and reached a maximum of 108 pfu at 31/1620 UTC.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels. A slight chance of
active conditions exist on day one with the potential for a weak
shock passage from the west limb CME of 29 December. The greater
than 10 MeV event is expected to end late on day one of the forecast
period.
III. Event Probabilities 01 Jan-03 Jan
Class M 75/75/75
Class X 15/15/15
Proton 99/50/10
PCAF in progress
IV. Penticton 10.7 cm Flux
Observed 31 Dec 246
Predicted 01 Jan-03 Jan 245/240/240
90 Day Mean 31 Dec 219
V. Geomagnetic A Indices
Observed Afr/Ap 30 Dec 015/017
Estimated Afr/Ap 31 Dec 008/012
Predicted Afr/Ap 01 Jan-03 Jan 015/015-010/010-008/008
VI. Geomagnetic Activity Probabilities 01 Jan-03 Jan
A. Middle Latitudes
Active 25/20/15
Minor storm 10/05/05
Major-severe storm 05/01/01
B. High Latitudes
Active 30/25/20
Minor storm 15/10/05
Major-severe storm 10/05/01