:Product: 20000923RSGA.txt
:Issued: 2000 Sep 23 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 267 ISSUED AT 2200Z ON 23 SEP 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  22/2100Z
TO 23/2100Z:  SOLAR ACTIVITY HAS BEEN LOW.  THE LARGEST EVENT OF THE
DAY WAS AN OPTICALLY UNCORRELATED C8 FLARE AT 22/2350 UTC.  EIT
IMAGERY SUGGESTS THIS EVENT WAS DUE TO ACTIVITY BEHIND THE NW LIMB.
ELSEWHERE, REGION 9169 (N11E04) REMAINS IMPRESSIVE IN SIZE AND
MAGNETIC COMPLEXITY, BUT ACTIVITY WAS LIMITED TO SEVERAL LESSER
C-CLASS SUBFAINT FLARES THROUGHOUT THE DAY, AND A DISAPPEARING
11-DEGREE SOLAR FILAMENT, THOUGH WITHOUT EVIDENCE OF ANY CME
ACTIVITY OF SIGNIFICANCE.  REGIONS 9166 (S11W44) AND 9167 (N14W11)
WERE ALSO SOURCES OF C-CLASS ACTIVITY.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE.  REGION 9169 REMAINS A LIKELY SOURCE OF ISOLATED MAJOR
FLARE ACTIVITY, AND REGION 9166 A POSSIBLE SOURCE OF MODERATE
ACTIVITY.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY 22/2100Z TO 23/2100Z:
THE GEOMAGNETIC FIELD WAS AT QUIET TO UNSETTLED LEVELS THROUGHOUT THE
DAY.  GREATER-THAN-2 MEV ELECTRONS AT GEOSYNCHRONOUS ORBIT WERE AT
MODERATE LEVELS DURING LOCAL DAYTIME HOURS.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO REMAIN AT QUIET TO UNSETTLED LEVELS THROUGH DAY ONE,
WITH AN INCREASED CHANCE OF ACTIVE LEVELS AND ISOLATED MINOR
STORMING ON DAYS TWO AND THREE, DUE TO THE EXPECTED INFLUENCE OF A
FAVORABLY POSITIONED CORONAL HOLE.  MODERATE ENHANCEMENTS OF
GREATER-THAN-2 MEV ELECTRONS AT GEOSYNCHRONOUS ORBIT ARE EXPECTED
TO RECUR DURING LOCAL DAYTIME HOURS THROUGHOUT THE PERIOD.
III.  EVENT PROBABILITIES 24 SEP-26 SEP
CLASS M    70/70/70
CLASS X    25/25/25
PROTON     05/10/10
PCAF       YELLOW
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           23 SEP 225
PREDICTED   24 SEP-26 SEP  225/225/220
90 DAY MEAN        23 SEP 180
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 22 SEP  006/007
ESTIMATED AFR/AP 23 SEP  007/008
PREDICTED AFR/AP 24 SEP-26 SEP  010/010-018/020-015/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 24 SEP-26 SEP
A.  MIDDLE LATITUDES
ACTIVE                20/25/25
MINOR STORM           10/15/15
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                25/30/30
MINOR STORM           10/15/15
MAJOR-SEVERE STORM    01/01/01
VII.  COMMENTS
EFFECTIVE 2 OCT 2000, SEC WILL ISSUE ITS TEXT PRODUCTS IN MIXED
CASE VS. ALL UPPER CASE.  THIS CHANGE WILL BE VISIBLE ON ALL SEC
PRODUCT DELIVERY SYSTEMS EXCEPT FOR TELETYPE CIRCUITS.  ONLY THE
CASE OF THE TEXT IN EACH PRODUCT WILL CHANGE, NOT THE FORMAT OR
SPACING WITHIN THE PRODUCT.  FOR DETAILS SEE OUR WEBSITE AT
SEC.NOAA.GOV/MIXEDCASE.HTML