:Product: 19990901RSGA.txt
:Issued: 1999 Sep 01 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 244 ISSUED AT 2200Z ON 01 SEP 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  31/2100Z
TO 01/2100Z:  SOLAR ACTIVITY HAS BEEN LOW FOR THE PAST 24 HOURS.  THE
LARGEST EVENT WAS A C6/SF FLARE FROM REGION 8674 (S24W72).  NO NEW
REGIONS WERE NUMBERED,  THE X-RAY BACKGROUND LEVEL WAS NEAR OR
EXCEEDED C1 FOR MOST OF THE PERIOD.  SURGING WAS REPORTED ON THE
WEST LIMB NEAR S20 AS REGION 8673 (S19W94) ROUNDED THE LIMB.  A
FILAMENT LOCATED NEAR S10W25 ON 8/31/1500 UT WAS GONE BY 9/01/1538
UT. FILAMENT GROWTH WAS NOTED NEAR S25W10.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE FOR THE NEXT THREE DAYS. ISOLATED M-CLASS EVENTS ARE
POSSIBLE FROM REGION 8674 AND REGION 8681.  BOTH REGIONS ARE
MODERATELY MAGNETICALLY COMPLEX.  DEVELOPMENT MAY BE OCCURRING IN
THE SOUTHWEST QUADRANT NEAR REGIONS 8686 (S24W09) AND 8679 (S36W17).
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 31/2100Z TO 01/2100Z:
THE GEOMAGNETIC FIELD HAS BEEN UNSETTLED TO ACTIVE FOR THE PAST 24
HOURS, WITH ONE PERIOD AT MINOR STORMS LEVELS (06-09 UT). THIS
ACTIVITY WAS CAUSED BY RELATIVELY STEADY, MODERATE VELOCITY (NEAR
550 KM/S) SOLAR WIND WITH A CONSISTENTLY SOUTHWARD MAGNETIC FIELD
(NEAR 5 NT). THE SECTOR POLARITY WAS POSITIVE (AWAY).  ENERGETIC
ELECTRON FLUXES AT GEOSYNCHRONOUS ORBIT REACHED HIGH LEVELS DURING
THE PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO PERSIST AT UNSETTLED TO ACTIVE CONDITIONS, WITH ISOLATED
PERIODS AT STORM LEVELS.  THE OVERALL LEVEL OF ACTIVITY IS EXPECTED
TO DECLINE TOWARD PREDOMINATELY UNSETTLED CONDITIONS BY THE END OF
THE FORECAST PERIOD.  A SOLAR PROTON EVENT IS POSSIBLE BUT IS NOT
CONSIDERED LIKELY.
III.  EVENT PROBABILITIES 02 SEP-04 SEP
CLASS M    50/40/30
CLASS X    10/10/05
PROTON     10/10/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           01 SEP 163
PREDICTED   02 SEP-04 SEP  155/150/145
90 DAY MEAN        01 SEP 169
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 31 AUG  012/018
ESTIMATED AFR/AP 01 SEP  020/018
PREDICTED AFR/AP 02 SEP-04 SEP  018/012-015/012-010/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 02 SEP-04 SEP
A.  MIDDLE LATITUDES
ACTIVE                20/15/10
MINOR STORM           15/10/05
MAJOR-SEVERE STORM    05/05/01
B.  HIGH LATITUDES
ACTIVE                25/20/20
MINOR STORM           20/15/10
MAJOR-SEVERE STORM    20/05/05