:Product: 20001128RSGA.txt
:Issued: 2000 Nov 28 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 333 Issued at 2200Z on 28 Nov 2000
IA.  Analysis of Solar Active Regions and Activity from  27/2100Z
to 28/2100Z:  Solar activity was low. Low-level C-class activity
continued. The largest flare was a C4/Sn at 27/2352 UTC in Region
9242 (N19E11). This is still a small sunspot group but is developing
and has produced a number of subflares. Region 9236 (N19W64) remains
the largest sunspot group on the visible disk but since yesterday
has only produced minor flares without significant X-ray output.
This active region is slowly decaying in all parameters. New Regions
9245 (N04E65) and 9246 (S12E47) were numbered.
IB.  Solar Activity Forecast:  Solar activity is expected to be low
to moderate. C-class activity is possible in Regions 9236, 9242,
9244, and 9246. Region 9236 may produce another major flare before
it completely decays or departs the visible disk.
IIA.  Geophysical Activity Summary 27/2100Z to 28/2100Z:
The geomagnetic field ranged from quiet to major storm levels. A
shock, presumably from CME's occurring on November 25 or 26, was
observed at the NASA ACE spacecraft at 28/0459 UTC. The greater than
10 MeV proton event continues in progress. The present particle flux
is about 20 pfu and is slowly declining.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at active to storm levels becoming quiet to unsettled
as the present disturbance subsides. The most recent CME (see Part
IIA) is the last one expected from the flare/CME activity of the
last several days. The greater that 10 MeV proton event is expected
to end within the next 24 hours.
III.  Event Probabilities 29 Nov-01 Dec
Class M    60/40/30
Class X    15/05/01
Proton     15/05/01
PCAF       yellow
IV.  Penticton 10.7 cm Flux
Observed           28 Nov 196
Predicted   29 Nov-01 Dec  195/190/180
90 Day Mean        28 Nov 176
V.  Geomagnetic A Indices
Observed Afr/Ap 27 Nov  027/038
Estimated Afr/Ap 28 Nov  030/035
Predicted Afr/Ap 29 Nov-01 Dec  015/025-010/020-010/015
VI.  Geomagnetic Activity Probabilities 29 Nov-01 Dec
A.  Middle Latitudes
Active                20/10/10
Minor storm           10/05/05
Major-severe storm    05/01/01
B.  High Latitudes
Active                30/25/20
Minor storm           20/15/10
Major-severe storm    10/05/01