:Product: 19990830RSGA.txt
:Issued: 1999 Aug 30 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 242 ISSUED AT 2200Z ON 30 AUG 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  29/2100Z
TO 30/2100Z:  SOLAR ACTIVITY BECAME MODERATE. REGION 8681 (N21W16)
PRODUCED AN M3/2B AT 30/1805Z. THIS EVENT WAS ACCOMPANIED BY A
MODERATE INTENSITY TYPE II. THE GROWTH RATE SLOWED IN THIS REGION
BUT IT MAINTAINED ITS ANOMALOUS MAGNETIC CONFIGURATION. REGION 8674
(S24W50) PRODUCED A C9/1N AT 30/1448Z. THIS REGION EXHIBITED
MODERATE DECAY IN SUNSPOT NUMBER AND AREAL COVERAGE. NOTIFICATION
WAS RECEIVED OF A PARTIAL HALO CME EVENT WITH THE X1 FLARE AT
28/1805Z FROM REGION 8674. HOWEVER, THE VAST MAJORITY OF THE
MATERIAL WAS SEEN TO MOVE OUT OF THE ECLIPTIC AND THE EVENT IS
DIFFICULT TO INTERPRET. IT IS UNKNOWN AT THIS TIME IF THERE WAS A
HALO CME WITH THE M3 FLARE ABOVE FROM REGION 8681.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO REMAIN
PREDOMINANTLY MODERATE WITH M-CLASS EVENTS POSSIBLE FROM REGIONS
8674 AND 8681. X-CLASS EVENTS REMAIN POSSIBLE FROM REGION 8674 BUT
THAT POSSIBILITY DECREASES AS THE REGION DECAYS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 29/2100Z TO 30/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED WITH THE EXCEPTION OF
THE 30/0800-1200Z INTERVAL. DURING THAT TIME ACTIVE TO MINOR STORM
CONDITIONS WERE OBSERVED. THIS DISTURBANCE DOES NOT APPEAR TO BE
RELATED TO THE IMPACT OF A CORONAL MASS EJECTION. RATHER, BZ TURNED
SOUTHWARD PRIOR TO THAT TIME WHILE OTHER SOLAR WIND PARAMETERS
REMAINED UNREMARKABLE. ENERGETIC ELECTRON FLUXES AT GEOSYNCHRONOUS
ORBIT REMAINED AT HIGH LEVELS.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD
RANGE FROM UNSETTLED TO ACTIVE LEVELS ON 31 AUG. ISOLATED MINOR
STORMING IS POSSIBLE. THIS DISTURBANCE IS EXPECTED IN RESPONSE TO
THE PARTIAL HALO CME/X1 FLARE MENTIONED ABOVE. HAD THE CME BEEN
AIMED DIRECTLY AT THE EARTH, A MUCH LARGER STORM WOULD BE EXPECTED.
UNSETTLED TO SLIGHTLY ACTIVE CONDITIONS ARE FORECAST FOR 01-02 SEP.
THE FORECAST FOR 02 SEP WILL BECOME ELEVATED IF NOTIFICATION IS
RECEIVED THAT THE M3/2B EVENT TODAY PRODUCED A HALO OR PARTIAL HALO
CME. THERE IS A POSSIBILITY OF AN ENERGETIC SOLAR PROTON EVENT
DURING THE PERIOD.
III.  EVENT PROBABILITIES 31 AUG-02 SEP
CLASS M    80/80/80
CLASS X    30/30/30
PROTON     25/25/25
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           30 AUG 198
PREDICTED   31 AUG-02 SEP  194/185/165
90 DAY MEAN        30 AUG 169
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 29 AUG  006/010
ESTIMATED AFR/AP 30 AUG  013/015
PREDICTED AFR/AP 31 AUG-02 SEP  015/015-012/012-010/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 31 AUG-02 SEP
A.  MIDDLE LATITUDES
ACTIVE                30/30/30
MINOR STORM           15/15/15
MAJOR-SEVERE STORM    05/05/05
B.  HIGH LATITUDES
ACTIVE                30/30/30
MINOR STORM           15/15/15
MAJOR-SEVERE STORM    05/05/05