Status Report

NOAA SEC Report of Solar-Geophysical Activity 26 Oct 2001

By SpaceRef Editor
October 26, 2001
Filed under , ,
:Product: Report of Solar-Geophysical Activity
:Issued: 2001 Oct 26 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 299 Issued at 2200Z on 26 Oct 2001
IA.  Analysis of Solar Active Regions and Activity from  25/2100Z
to 26/2100Z:  Solar activity was at moderate levels.  Region 9678
(N11E07) was active producing six C-class flares and one M2/Sn flare
at 26/1435 UTC.  Radio sweeps at numerous discrete frequencies were
reported with the M2/Sn flare.  This region continued rapid growth
in area coverage to 680 millionths, spot count to 48, and remains a
magnetically complex beta-gamma-delta configuration.  Region 9672
(S18W41) was also active producing four C-class and one minor
M-class flares.  As Region 9682 (N11E59) rotates onto the disc it
has developed into a major region with good potential for activity. 
New Region 9683 (N28E30) was numbered today.
IB.  Solar Activity Forecast:  Solar Activity is expected to be at
low to moderate levels.  There is a chance of an isolated major
flare from Regions 9672, 9678, or 9682.  Region 9672 still maintains
a complex magnetic configuration and it has not diminished in size
or complexity.  Continued rapid growth and complexity of Region 9678
makes this region a potential source for a major flare.
IIA.  Geophysical Activity Summary 25/2100Z to 26/2100Z:
The geomagnetic field was at quiet levels.  A coronal hole/high speed
stream has begun to rotate into a geoeffective position.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be at quiet to major storm levels.  The shock arrival
from the X1/2b CME on 25/1502 UTC is expected to arrive late on day
one or early on day two of the period.  Shock arrival is expected to
produce unsettled to minor storm level activity for day one and two
of the period.  Major storm levels are possible particularly at the
higher latitudes.  Coronal hole/high speed stream may keep activity
at unsettled levels on day three.
III.  Event Probabilities 27 Oct-29 Oct
Class M    75/75/75
Class X    35/35/30
Proton     20/20/15
PCAF       yellow
IV.  Penticton 10.7 cm Flux
Observed           26 Oct 237
Predicted   27 Oct-29 Oct  230/225/220
90 Day Mean        26 Oct 197
V.  Geomagnetic A Indices
Observed Afr/Ap 25 Oct  005/007
Estimated Afr/Ap 26 Oct  006/005
Predicted Afr/Ap 27 Oct-29 Oct  020/020-030/030-015/015
VI.  Geomagnetic Activity Probabilities 27 Oct-29 Oct
A.  Middle Latitudes
Active                50/50/50
Minor storm           25/30/20
Major-severe storm    15/15/05
B.  High Latitudes
Active                45/45/30
Minor storm           35/35/20
Major-severe storm    20/20/10

SpaceRef staff editor.