NOAA SEC Report of Solar-Geophysical Activity 23 Oct 2001
:Product: Report of Solar-Geophysical Activity
:Issued: 2001 Oct 23 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 296 Issued at 2200Z on 23 Oct 2001
IA. Analysis of Solar Active Regions and Activity from 22/2100Z
to 23/2100Z: Solar activity was at high levels. The largest flare
for the period was from Region 9672 (N18E00), which produced an
M6/1b flare at 23/0223 UTC and an M1/Sn flare at 23/0023 UTC. The
magnetic beta-gamma-delta configuration appears to have grown
stronger since the latest M-class flare occurrence from this region.
Multiple C-class flares were observed during the period. Region
9676 (N14E30) produced a C7/1f at 23/0803 UTC and Region 9678
(N07E48) produced several minor C-class flares early in period.
Three new regions were numbered today, Region 9678, Region 9679
(S10E58), and Region 9680 (N22E61).
IB. Solar Activity Forecast: Solar activity is expected to remain
at moderate to high levels. Region 9672 continues to show a strong
delta magnetic configuration.
IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field was at quiet to active levels with an isolated
period (23/0300 to 0600 UTC) of minor storm conditions at USAF
planetary. The greater than 10 MeV proton flux event at
geosynchronous orbit exceeded threshold at 22/1910 UTC, and reached
a maximum of 24 pfu at 22/2130 UTC. The event ended at 23/0115 UTC.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to major storm levels. The M6/2n and the
X1/2b flares from Region 9672 (that occurred during the last
forecast period) have both produced CME activity on LASCO/EIT
imagery. Analysis indicates that both shock arrivals may occur
between the early and middle period of day one resulting in storm
conditions to occur on day one and two of the forecast period.
III. Event Probabilities 24 Oct-26 Oct
Class M 80/80/70
Class X 40/40/25
IV. Penticton 10.7 cm Flux
Observed 23 Oct 226
Predicted 24 Oct-26 Oct 225/220/220
90 Day Mean 23 Oct 193
V. Geomagnetic A Indices
Observed Afr/Ap 22 Oct 033/066
Estimated Afr/Ap 23 Oct 015/017
Predicted Afr/Ap 24 Oct-26 Oct 030/040-025/040-012/012
VI. Geomagnetic Activity Probabilities 24 Oct-26 Oct
A. Middle Latitudes
Minor storm 40/30/10
Major-severe storm 15/10/01
B. High Latitudes
Minor storm 50/40/15
Major-severe storm 20/05/01