NOAA/USAF Report of Solar-Geophysical Activity 27 Nov 2000
:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Nov 27 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 332 Issued at 2200Z on 27 Nov 2000
IA. Analysis of Solar Active Regions and Activity from 26/2100Z
to 27/2100Z: Solar activity was low. Only a few low-level C-class
flares occurred. Region 9236 (N19W51) has started to decline in most
parameters since yesterday's major flare. New Region 9244 (N15W30)
is emerging rapidly to the east of 9236 and has already generated a
C-class subflare. New Region 9243 (S12E30) was also numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be
moderate to high. Region 9236 retains enough magnetic complexity for
another major flare. If Region 9244 continues to emerge at its
present rate it could start producing low-level M-class activity.
IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z:
The geomagnetic field ranged from unsettled to major storm levels.
This activity has been in response to the flare/CME activity on
24-25 November. The greater than 10 MeV proton event remains in
progress but is declining. The peak flux was 942 pfu at 26/2030 UTC.
The greater than 100 MeV proton event ended at 26/2040 UTC.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at active to major storm levels. CME's that occurred
on 26-27 November are expected to extend the present disturbance.
Barring any new CME's, the level of geomagnetic activity is expected
to diminish to unsettled to active levels by the third day of the
forecast period. The greater than 10 MeV proton event is expected to
continue its decay, ending within the next 48 hours.
III. Event Probabilities 28 Nov-30 Nov
Class M 70/60/50
Class X 30/20/10
PCAF in progress
IV. Penticton 10.7 cm Flux
Observed 27 Nov 192
Predicted 28 Nov-30 Nov 185/180/175
90 Day Mean 27 Nov 175
V. Geomagnetic A Indices
Observed Afr/Ap 26 Nov 019/022
Estimated Afr/Ap 27 Nov 040/040
Predicted Afr/Ap 28 Nov-30 Nov 030/040-030/025-020/020
VI. Geomagnetic Activity Probabilities 28 Nov-30 Nov
A. Middle Latitudes
Minor storm 20/20/10
Major-severe storm 30/25/10
B. High Latitudes
Minor storm 40/30/10
Major-severe storm 25/15/05