:Product: 19980820RSGA.txt
:Issued: 1998 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 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  19/2100Z
TO 20/2100Z:  SOLAR ACTIVITY HAS BEEN HIGH WITH A SINGLE X3.9 FLARE
AT 19/2145 FROM REGION 8307 (N32E60).  THERE WAS AN ASSOCIATED TYPE
II AND IV SWEEP INDICATING A SHOCK WITH A SPEED OF 1400 KM/S +/-200
KM/S.  REGION 8310 (N23E66) AND 8311 (N19E01) WERE NUMBERED TODAY.
REGION 8307 HAS MOVED FAR ENOUGH ONTO THE DISK THAT A RELIABLE
CLASSIFICATION HAS BEEN PERFORMED.  IT IS CLASSIFIED AS A EKO BETA
DELTA WITH 8 SPOTS AND AN AREA OF 440 MILLIONTHS.  THE MAGNETIC
CLASSIFICATION STILL NEEDS TO BE REFINED AS THE SPOT MOVES CLOSER TO
CENTER DISK.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE TO HIGH THROUGHOUT THE PERIOD.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 19/2100Z TO 20/2100Z:
THE GEOMAGNETIC FIELD HAS BEEN UNSETTLED TO ACTIVE.  DATA FROM THE
ACE SPACECRAFT INDICATE THAT A SMALL, SLOW SHOCK PASSED BY EARTH
OVER THE LAST 20 HOURS.  ENHANCED DENSITY, SLOW BULK SPEED, AND
SEMI-SMOOTH TRANSITION OF BZ FROM NEGATIVE TO POSITIVE CONTRIBUTED
TO THIS CONCLUSION.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO ACTIVE WITH PERIODS OF MINOR STORM AT HIGHER
LATITUDES.
III.  EVENT PROBABILITIES 21 AUG-23 AUG
CLASS M    75/75/75
CLASS X    40/40/40
PROTON     15/15/15
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           20 AUG 139
PREDICTED   21 AUG-23 AUG  142/146/150
90 DAY MEAN        20 AUG 115
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 19 AUG  006/009
ESTIMATED AFR/AP 20 AUG  015/015
PREDICTED AFR/AP 21 AUG-23 AUG  025/020-020/018-015/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 21 AUG-23 AUG
A.  MIDDLE LATITUDES
ACTIVE                20/20/15
MINOR STORM           10/10/05
MAJOR-SEVERE STORM    05/05/05
B.  HIGH LATITUDES
ACTIVE                30/25/20
MINOR STORM           15/10/10
MAJOR-SEVERE STORM    05/05/05