:Product: 19990819RSGA.txt
:Issued: 1999 Aug 19 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 231 ISSUED AT 2200Z ON 19 AUG 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  18/2100Z
TO 19/2100Z:  SOLAR ACTIVITY WAS MODERATE. REGION 8672 (N15W17)
PRODUCED AN M1/1N AT 1205Z, BUT LITTLE ELSE. REGION 8668 (N22E01)
STILL DOMINATES THE DISK, BUT WAS STABLE. NEWLY ASSIGNED REGION 8673
(S17E81) ROTATED INTO VIEW. THIS IS THE APPARENT RETURN OF OLD
REGION 8647, THE SITE OF M AND X CLASS ACTIVITY LAST ROTATION.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. MORE ISOLATED M-CLASS EVENTS MAY OCCUR FROM REGIONS
8668 AND 8673.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 18/2100Z TO 19/2100Z:
THE GEOMAGNETIC FIELD WAS AT UNSETTLED TO MINOR STORM LEVELS DURING
THE DAY. THE SOLAR WIND IS STILL GUSTING TO SPEEDS NEAR 800 KM/S,
DRIVING THIS ELEVATED MAGNETIC ACTIVITY. THE GREATER THAN 2 MEV
ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT PERSISTED AT HIGH LEVELS
THROUGHOUT THE PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE THE NEXT 24 HOURS. THE CURRENT
DISTURBANCE SHOULD SLOWLY WEAKEN AND YIELD TO UNSETTLED CONDITIONS
BY THE END OF THE INTERVAL.
III.  EVENT PROBABILITIES 20 AUG-22 AUG
CLASS M    25/25/25
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           19 AUG 135
PREDICTED   20 AUG-22 AUG  140/145/150
90 DAY MEAN        19 AUG 163
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 18 AUG  028/026
ESTIMATED AFR/AP 19 AUG  020/020
PREDICTED AFR/AP 20 AUG-22 AUG  015/020-015/015-010/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 20 AUG-22 AUG
A.  MIDDLE LATITUDES
ACTIVE                40/30/20
MINOR STORM           15/10/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                50/40/30
MINOR STORM           20/15/10
MAJOR-SEVERE STORM    05/01/01