:Product: 19990829RSGA.txt
:Issued: 1999 Aug 29 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 241 ISSUED AT 2200Z ON 29 AUG 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  28/2100Z
TO 29/2100Z:  SOLAR ACTIVITY BECAME LOW. THE LARGEST EVENT OF THE
PERIOD WAS A C9/1N FROM REGION 8681 (N22W03) AT 29/1731Z. THIS
REGION CONTINUED TO EMERGE RAPIDLY AND EXHIBITED AN ABNORMAL
MAGNETIC CONFIGURATION OF A NEGATIVE ISLAND SURROUNDED BY POSITIVE
POLARITY. REGION 8674 (S23W40) STABILIZED. THE LARGEST EVENT IT
PRODUCED WAS A C4/SF AT 29/1229Z. THIS REGION MAINTAINED THE
MAGNETIC COMPLEXITY IT HAS EXHIBITED DURING THE LAST SEVERAL DAYS
BUT IT SHOWED NO REGION DYNAMICS SUCH AS GROWTH AND SPOT PROPER
MOTION. THE X1 FLARE AT 28/1805Z PRODUCED A LARGE CORONAL MASS
EJECTION THAT MOVED SOUTHWARD OUT OF THE ECLIPTIC.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD BE PREDOMINANTLY
MODERATE. REGION 8674 RETAINS THE CAPABILITY OF PRODUCING M-CLASS
AND POSSIBLY ADDITIONAL X-CLASS EVENTS. HOWEVER, THE FREQUENCY OF
EVENTS SHOULD LESSEN AS THIS REGION BEGINS A SLOW PERIOD OF DECAY.
REGION 8681 SHOULD PRODUCE FREQUENT C-CLASS EVENTS AND NOW POSSESSES
THE POTENTIAL FOR SMALL M-CLASS FLARES.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 28/2100Z TO 29/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. SOLAR WIND VELOCITY
DECLINED DURING THE PERIOD TO JUST OVER 500 KM/S. ENERGETIC ELECTRON
FLUXES AT GEOSYNCHRONOUS WERE HIGH.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD BE
GENERALLY QUIET TO UNSETTLED FOR THE NEXT THREE DAYS. NONE OF MANY
RECENT CORONAL MASS EJECTIONS ARE EXPECTED TO IMPACT THE EARTH
HEAD-ON BUT IT IS POSSIBLE THE FLANKS OF SOME OF THE CMES COULD
REACH THE EARTH. THEREFORE, ISOLATED ACTIVE, TO POSSIBLY MINOR
STORM, PERIODS ARE POSSIBLE FOR THE ENTIRE PERIOD. ENERGETIC
ELECTRON FLUXES SHOULD REMAIN AT HIGH LEVELS FOR 1-2 MORE DAYS. THE
POSSIBLY EXISTS FOR A SOLAR PROTON EVENT DURING THE PERIOD. REGION
8674 IS THE PROBABLE SOURCE.
III.  EVENT PROBABILITIES 30 AUG-01 SEP
CLASS M    75/75/75
CLASS X    40/40/40
PROTON     30/30/30
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           29 AUG 218
PREDICTED   30 AUG-01 SEP  220/217/197
90 DAY MEAN        29 AUG 168
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 28 AUG  011/014
ESTIMATED AFR/AP 29 AUG  008/010
PREDICTED AFR/AP 30 AUG-01 SEP  010/012-012/015-012/012
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 30 AUG-01 SEP
A.  MIDDLE LATITUDES
ACTIVE                15/30/30
MINOR STORM           05/15/15
MAJOR-SEVERE STORM    05/05/05
B.  HIGH LATITUDES
ACTIVE                15/30/30
MINOR STORM           05/15/15
MAJOR-SEVERE STORM    05/05/05