:Product: 19980822RSGA.txt
:Issued: 1998 Aug 22 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 234 ISSUED AT 2200Z ON 22 AUG 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  21/2100Z
TO 22/2100Z:  SOLAR ACTIVITY BECAME HIGH. REGION 8307 (N31E35)
PRODUCED AN IMPULSIVE M9/2B AT 22/0009Z WITH A TYPE IV RADIO SWEEP
EVENT AND MODERATE RADIO BURSTS IN THE GHZ RANGE. THIS REGION
EXHIBITED SOME GROWTH, ESPECIALLY IN THE NORTHERN PORTION OF THE
REGION WHERE A DELTA CONFIGURATION IS FORMING. REGION 8307 PRODUCED
SEVERAL OTHER SMALL C-CLASS EVENTS DURING THE PERIOD.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD BE MODERATE TO
HIGH DURING THE NEXT THREE DAYS. REGION 8307 MAINTAINS THE
CAPABILITY OF PRODUCING MID-LEVEL M-CLASS EVENTS AND OCCASIONAL
X-CLASS EVENTS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 21/2100Z TO 22/2100Z:
THE GEOMAGNETIC FIELD WAS PREDOMINANTLY QUIET EARLY IN THE PERIOD. A
DISTURBANCE OCCURRED BETWEEN 22/0600Z TO APPROXIMATELY 22/1300Z.
ACTIVE TO MAJOR STORM CONDITIONS WERE OBSERVED DURING THAT TIME.
SOME HIGH LATITUDE SENSORS RECORDED PERIODS OF SEVERE STORMING. THE
FIELD WAS UNSETTLED TO SLIGHTLY ACTIVE FOR THE REMAINDER OF THE
PERIOD. SOLAR WIND DATA DURING THE DISTURBANCE SHOWED A LOW SPEED,
MODERATELY HIGH DENSITY FLOW IN THE VICINITY OF THE EARTH. THESE
SOLAR WIND CONDITIONS ARE NOT CHARACTERISTIC OF CORONAL HOLE RELATED
STREAMS. HOWEVER, AT THE END OF THE PERIOD, SOLAR WIND VELOCITY WAS
INCREASING AND DENSITY DECREASING. THE GREATER THAN 10 MEV PROTON
FLUXES HAVE BEEN SLIGHTLY ELEVATED ABOVE BACKGROUND BUT BELOW EVENT
THRESHOLD SINCE EARLY ON 20 AUG.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE PREDOMINANTLY UNSETTLED TO ACTIVE FOR THE NEXT THREE
DAYS. PERIODS OF MINOR STORMING ARE POSSIBLE EACH DAY BUT ESPECIALLY
ON 25 AUG WHEN A SMALL DISTURBANCE RELATED TO THE M9 EVENT MENTIONED
ABOVE IS EXPECTED TO REACH THE EARTH. AN ENERGETIC SOLAR PROTON
EVENT IS POSSIBLE DURING THE PERIOD SHOULD REGION 8307 PRODUCE
ANOTHER LARGE EVENT.
III.  EVENT PROBABILITIES 23 AUG-25 AUG
CLASS M    80/80/80
CLASS X    30/30/30
PROTON     20/25/30
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           22 AUG 133
PREDICTED   23 AUG-25 AUG  136/139/142
90 DAY MEAN        22 AUG 116
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 21 AUG  003/006
ESTIMATED AFR/AP 22 AUG  017/020
PREDICTED AFR/AP 23 AUG-25 AUG  015/020-015/020-020/020
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 23 AUG-25 AUG
A.  MIDDLE LATITUDES
ACTIVE                30/30/30
MINOR STORM           15/15/20
MAJOR-SEVERE STORM    05/05/10
B.  HIGH LATITUDES
ACTIVE                30/30/30
MINOR STORM           15/15/20
MAJOR-SEVERE STORM    05/05/10