NOAA/USAF Report of Solar-Geophysical Activity 25 September 2000

:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Sep 25 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 269 ISSUED AT 2200Z ON 25 SEP 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  24/2100Z
TO 25/2100Z:  SOLAR ACTIVITY WAS MODERATE. REGION 9166 (S12W70)
PRODUCED AN M3/1N FLARE AT 25/0053Z AND SEVERAL MINOR C-CLASS FLARES
THROUGHOUT THE PERIOD. THIS REGION HAS UNDERWENT SLOW DECAY OVER THE
PAST FEW DAYS, BUT MAINTAINS MODERATE COMPLEXITY. REGION 9169
(N11W22) PRODUCED AN M1 FLARE AT 25/0215Z WITH MODERATE CENTIMETRIC
BURSTS INCLUDING A 450SFU TENFLARE. A CME WAS ALSO OBSERVED. SOME
DECAY WAS NOTED IN THIS LARGE AND MODERATELY COMPLEX REGION WHICH
NOW MEASURES 1400 MILLIONTHS OF WHITE LIGHT AREA.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO CONTINUE
AT LOW TO MODERATE LEVELS. REGIONS 9166 AND 9169 WILL CONTINUE TO
PRODUCE C-CLASS FLARES WITH AN ISOLATED M-CLASS FLARE LIKELY.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY 24/2100Z TO 25/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE. PROLONGED PERIODS OF
SOUTHWARD BZ AND ENHANCED SOLAR WIND SPEED PRODUCED OCCASIONAL
ACTIVE PERIODS. THE GREATER THAN 2 MEV ELECTRONS AT GEOSYNCHRONOUS
ORBIT WERE AT MOSTLY MODERATE TO HIGH LEVELS.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE PREDOMINANTLY QUIET TO UNSETTLED WITH OCCASIONAL
ACTIVE PERIODS ON DAY ONE. ACTIVE TO MINOR STORM CONDITIONS ARE
POSSIBLE ON DAY TWO FROM AN EXPECTED CME PASSAGE FROM TODAY'S M1
FLARE IN REGION 9169 AT 02/0215Z. A RETURN TO QUIET TO UNSETTLED
CONDITIONS IS EXPECTED BY DAY THREE.
III.  EVENT PROBABILITIES 26 SEP-28 SEP
CLASS M    60/50/50
CLASS X    20/20/20
PROTON     10/10/10
PCAF       YELLOW
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           25 SEP 226
PREDICTED   26 SEP-28 SEP  220/210/200
90 DAY MEAN        25 SEP 180
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 24 SEP  009/010
ESTIMATED AFR/AP 25 SEP  017/018
PREDICTED AFR/AP 26 SEP-28 SEP  015/015-020/020-012/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 26 SEP-28 SEP
A.  MIDDLE LATITUDES
ACTIVE                30/40/30
MINOR STORM           20/30/20
MAJOR-SEVERE STORM    05/10/05
B.  HIGH LATITUDES
ACTIVE                40/50/40
MINOR STORM           30/40/30
MAJOR-SEVERE STORM    05/10/05