:Product: 19990623RSGA.txt
:Issued: 1999 Jun 23 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 174 ISSUED AT 2200Z ON 23 JUN 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  22/2100Z
TO 23/2100Z:  SOLAR ACTIVITY WAS MODERATE.  THE LARGEST EVENT WAS AN
M1/2N FLARE AT 23/0709Z FROM REGION 8598 (N23E43).  THIS FLARE WAS
ACCOMPANIED BY A TYPE IV RADIO SWEEP AS WELL AS MULTI-FREQUENCY
RADIO BURSTS.  AT 23/0047Z A C7/1F FLARE OCCURRED, ORIGINATING FROM
UNSPOTTED REGION 8583 (S11W90).  THROUGHOUT THE PERIOD BACKGROUND
X-RAY FLUX LEVELS HOVERED AT OR NEAR C LEVELS WITH FREQUENT SMALL
C-CLASS EVENTS. REGION 8598, WHICH LIES WITHIN A LARGE CLUSTER OF
REGIONS IN THE NORTHEAST QUADRANT OF THE DISK, IS THE LARGEST AND
MOST MAGNETICALLY COMPLICATED SPOT GROUP ON THE DISK.  REGIONS 8601
(S15W36), 8602 (N19E75), 8603 (S16E75) WERE NUMBERED TODAY.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE.  GROWTH AND MAGNETIC INTERACTION WITHIN THE LARGE
NORTHEAST CLUSTER OF REGIONS INCREASES THE CHANCES OF M-CLASS FLARES
OVER THE NEXT SEVERAL DAYS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 22/2100Z TO 23/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET THROUGHOUT THE PERIOD.  RECENT
ANALYSIS OF SOHO IMAGERY INDICATED THE PRESENCE OF A HALO CME
ASSOCIATED WITH THE M1/1N FLARE ON 22/1829Z AND THE POSSIBILITY OF
ANOTHER GEOEFFECTIVE CME WITH TODAY'S M1 FLARE.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET ON THE FIRST DAY OF THE FORECAST PERIOD.  BY
THE SECOND AND THIRD DAYS THE EFFECT OF THE OBSERVED CMES ARE
FORECAST TO INCREASE THE FIELD TO UNSETTLED TO ACTIVE CONDITIONS
WITH A CHANCE FOR MINOR STORMING.
III.  EVENT PROBABILITIES 24 JUN-26 JUN
CLASS M    60/60/60
CLASS X    05/05/05
PROTON     20/20/20
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           23 JUN 168
PREDICTED   24 JUN-26 JUN  175/180/180
90 DAY MEAN        23 JUN 138
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 22 JUN  003/004
ESTIMATED AFR/AP 23 JUN  005/005
PREDICTED AFR/AP 24 JUN-26 JUN  005/005-015/015-015/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 24 JUN-26 JUN
A.  MIDDLE LATITUDES
ACTIVE                10/35/35
MINOR STORM           05/15/15
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                15/40/40
MINOR STORM           05/20/20
MAJOR-SEVERE STORM    01/01/01