Status Report

NOAA SEC Report of Solar-Geophysical Activity 24 Oct 2001

By SpaceRef Editor
October 24, 2001
Filed under , ,
:Product: Report of Solar-Geophysical Activity
:Issued: 2001 Oct 24 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 297 Issued at 2200Z on 24 Oct 2001
IA.  Analysis of Solar Active Regions and Activity from  23/2100Z
to 24/2100Z:  Solar activity was at low levels.  The largest flare
was a C6/Sf from Region 9678 (N07E34) at 24/1841 UTC.  This region
has increased in area (140 millionths), spot count (22) and magnetic
complexity (beta-gamma).  Region 9672 (S19W13) has increased in
arial coverage to 490 millionth, increased spot count to 26 and
maintains a beta-gamma-delta magnetic configuration.  This region
has produced minor C-class flares and has the potential for a major
flare.  Region 9669 (N14W51) also produced minor C-class flares.
IB.  Solar Activity Forecast:  Solar activity is expected to be at
low to moderate levels with a chance of an isolated high level
condition.  Region 9672 continues to have a good chance of producing
a major flare.  Region 9678 also has the potential for a major
IIA.  Geophysical Activity Summary 23/2100Z to 24/2100Z:
Geomagnetic activity was at quiet levels.  The shock arrival from the
two CMEs (M6/2N on 22/1502 UTC and X1/2B on 22/1759 UTC)) appears to
have lower shock velocity than expected.  No shock signature was
observed from the NASA ACE/EPAM, MAG, SWEPAM instruments as of the
time of this forecast issue.  Greater than 10 MeV protons were
elevated but continued slow decay.
IIB.  Geophysical Activity Forecast:  Geomagnetic activity is
expected to be at quiet to minor storm levels.  Further analysis of
the expected CME shock combined with the lack of shock signature by
ground and space based instruments indicates that the shock arrival
is expected on day one or even early on day two of the period. 
Shock arrival is expected to result in active to minor storm levels.
Geomagnetic activity is expected to return to quiet to unsettled
conditions by day three.  Greater than 10 MeV protons are expected
to remain elevated but continue to decay throughout the period
barring a major flare event.
III.  Event Probabilities 25 Oct-27 Oct
Class M    80/75/75
Class X    35/25/25
Proton     25/15/15
PCAF       yellow
IV.  Penticton 10.7 cm Flux
Observed           24 Oct 239
Predicted   25 Oct-27 Oct  225/220/215
90 Day Mean        24 Oct 194
V.  Geomagnetic A Indices
Observed Afr/Ap 23 Oct  010/015
Estimated Afr/Ap 24 Oct  008/010
Predicted Afr/Ap 25 Oct-27 Oct  030/040-015/020-010/015
VI.  Geomagnetic Activity Probabilities 25 Oct-27 Oct
A.  Middle Latitudes
Active                50/30/20
Minor storm           30/10/05
Major-severe storm    15/05/01
B.  High Latitudes
Active                50/30/25
Minor storm           35/20/15
Major-severe storm    15/05/05

SpaceRef staff editor.