:Product: 19980819RSGA.txt
:Issued: 1998 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 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  18/2100Z
TO 19/2100Z:  SOLAR ACTIVITY HAS BEEN HIGH. AN X4.9 OCCURRED AT
18/2210 AND WAS ASSOCIATED WITH REGION 8307 (N32E72).  AN M2.3 AT
19/1222 AND M3.0 AT 19/1404 WERE ALSO ASSOCIATED WITH THIS REGION.
THIS REGION IS EXPECTED TO CONTINUE TO PRODUCE X- AND M-CLASS
FLARES.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO MODERATE
TO HIGH THROUGHOUT THE PERIOD AS REGION 8307 MOVES TOWARDS THE
CENTER OF THE DISK.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 18/2100Z TO 19/2100Z:
THE GEOMAGNETIC FIELD HAS BEEN QUIET.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE WITH PERIODS OF MINOR STORM AT
HIGHER LATITUDES.  CORONAL HOLES ARE MOVING INTO A GEOEFFECTIVE
LOCATIONS FOR THE REMAINDER OF THE PERIOD.  AS REGION 8307 (N32E72)
ROTATES TO THE CENTER OF THE DISK, ERUPTIONS OF CMES ARE GOING TO BE
MORE GEOEFFECTIVE AS WELL.  TYPE II (IMPORTANCE 3) AND IV
(IMPORTANCE 2) BURSTS WERE ASSOCIATED WITH THE X4.9 AND M3.0 X-RAY
FLARES.  ESTIMATED SHOCK SPEED FROM X4.9 EVENT IS 1900 KM/S, AND
1000 KM/S +/- 200 KM/S FOR THE M3.0 FLARE.
III.  EVENT PROBABILITIES 20 AUG-22 AUG
CLASS M    75/75/75
CLASS X    30/30/30
PROTON     10/15/15
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           19 AUG 135
PREDICTED   20 AUG-22 AUG  138/140/144
90 DAY MEAN        19 AUG 114
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 18 AUG  003/006
ESTIMATED AFR/AP 19 AUG  010/010
PREDICTED AFR/AP 20 AUG-22 AUG  015/015-025/020-015/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 20 AUG-22 AUG
A.  MIDDLE LATITUDES
ACTIVE                10/20/20
MINOR STORM           05/10/10
MAJOR-SEVERE STORM    01/05/05
B.  HIGH LATITUDES
ACTIVE                15/25/25
MINOR STORM           05/10/15
MAJOR-SEVERE STORM    01/05/05