:Product: 19981222RSGA.txt
:Issued: 1998 Dec 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 356 ISSUED AT 2200Z ON 22 DEC 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  21/2100Z
TO 22/2100Z:  SOLAR ACTIVITY WAS LOW. REGION 8416 (N19E46) PRODUCED A
C1/SF AT 22/1833Z. THIS REGION EXHIBITED SLOW DECAY DURING THE
PERIOD. REGION 8415 (N20E12) PRODUCED SMALL SUBFLARES AND CONTINUED
TO SLOWLY DECAY AND SIMPLIFY. THE FILAMENT IN REGION 8414 (N26W23)
GREW SUBSTANTIALLY DURING THE PERIOD AND AT TIMES SHOWED STRONG
MOTION. RECENT X-RAY IMAGERY SHOWS A LARGE ENHANCED AREA OVER THE
NORTHEAST LIMB WHERE SEVERAL REGIONS ARE DUE TO RETURN.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD BE PREDOMINANTLY
LOW DURING THE NEXT THREE DAYS. REGION 8415 RETAINS THE CAPABILITY
OF PRODUCING AN ISOLATED M-CLASS EVENT. THE REGIONS RETURNING TO THE
EAST LIMB COULD INCREASE THE FREQUENCY OF C-CLASS EVENTS. BETTER
ASSESSMENT OF THEIR FLARE POTENTIAL MUST AWAIT THEIR APPEARANCE ONTO
THE VISIBLE DISK. THE FILAMENT IN REGION 8414 IS EXPECTED TO ERUPT
SOMETIME PRIOR TO WEST LIMB TRANSIT. IF IT DOES, A LONG DURATION
X-RAY EVENT AND LARGE CORONAL MASS EJECTION WOULD LIKELY OCCUR.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 21/2100Z TO 22/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET. THE DISTURBANCE FROM THE HALO
CORONAL MASS EJECTION ON 18 DEC FAILED TO MATERIALIZE.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD BE
QUIET TO SLIGHTLY UNSETTLED FOR THE NEXT THREE DAYS.
III.  EVENT PROBABILITIES 23 DEC-25 DEC
CLASS M    30/30/30
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           22 DEC 129
PREDICTED   23 DEC-25 DEC  132/135/137
90 DAY MEAN        22 DEC 133
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 21 DEC  003/003
ESTIMATED AFR/AP 22 DEC  005/011
PREDICTED AFR/AP 23 DEC-25 DEC  008/012-008/009-008/009
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 23 DEC-25 DEC
A.  MIDDLE LATITUDES
ACTIVE                15/10/05
MINOR STORM           05/05/01
MAJOR-SEVERE STORM    05/01/01
B.  HIGH LATITUDES
ACTIVE                20/10/05
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    05/01/01