:Product: 19990820RSGA.txt
:Issued: 1999 Aug 20 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 232 ISSUED AT 2200Z ON 20 AUG 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  19/2100Z
TO 20/2100Z:  SOLAR ACTIVITY WAS MODERATE. NEWLY NUMBERED REGION 8674
(S24E66) WAS BY FAR THE MOST ACTIVE REGION THIS PERIOD. THIS REGION
PRODUCED A LONG DURATION M1 X-RAY EVENT WITH MULTIPLE OPTICAL
SUBFLARES FROM 20/1236UT TO 20/1706UT. REGION 8674 ALSO PRODUCED AN
M1/SF ACCOMPANIED BY AN 180 SFU 10 CM BURST AND A WEAK TYPE II SWEEP
(400 KM/S) AT 20/1829UT AND A C7/SF AT 20/1927UT. AN 8 DEGREE
PROMINENCE ERUPTED ON THE NORTH-WEST LIMB (N47W74) AT 20/1530UT.
OTHER ACTIVE REGIONS WERE 8668 (N22W11), 8672 (N16W31), AND 8673
(S26E75) ALL OF WHICH PRODUCED OPTICAL SUBFLARES.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 19/2100Z TO 20/2100Z:
THE GEOMAGNETIC FIELD WAS AT UNSETTLED TO MINOR STORM LEVELS. THE
SOLAR WIND VELOCITY DROPPED FROM 750 KM/S AT THE BEGINNING OF THE
PERIOD TO 550 KM/S AT THE END OF THE PERIOD. THE GREATER THAN 2 MEV
ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS AT HIGH LEVELS FOR MOST OF
THE PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE THE NEXT 24 HOURS. AS THE SOLAR
WIND VELOCITY DROPS THE CURRENT DISTURBANCE SHOULD SLOWLY WEAKEN AND
UNSETTLED CONDITIONS CAN BE EXPECTED FOR THE REST OF THE FORECAST
PERIOD.
III.  EVENT PROBABILITIES 21 AUG-23 AUG
CLASS M    60/60/60
CLASS X    05/05/05
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           20 AUG 152
PREDICTED   21 AUG-23 AUG  155/160/165
90 DAY MEAN        20 AUG 163
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 19 AUG  019/022
ESTIMATED AFR/AP 20 AUG  020/030
PREDICTED AFR/AP 21 AUG-23 AUG  018/025-015/020-010/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 21 AUG-23 AUG
A.  MIDDLE LATITUDES
ACTIVE                01/01/01
MINOR STORM           01/01/01
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                01/01/01
MINOR STORM           01/01/01
MAJOR-SEVERE STORM    01/01/01