:Product: 19981231RSGA.txt
:Issued: 1998 Dec 31 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 365 ISSUED AT 2200Z ON 31 DEC 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  30/2100Z
TO 31/2100Z:  SOLAR ACTIVITY DECREASED TO LOW LEVELS. REGION 8421
(N27W27) CONTINUED TO PRODUCE FREQUENT C-CLASS FLARES. ALTHOUGH IT
SHOWED NO SIGNIFICANT CHANGES, IT REMAINED A LARGE GROUP WITH A
COMPACT SPOT DISTRIBUTION AND STRONG MAGNETIC GRADIENTS. REGION 8419
(N28W79) CONTINUED TO SLOWLY DECAY AS IT APPROACHED THE WEST LIMB.
THE REMAINING REGIONS WERE SMALL AND STABLE. NEW REGION 8427
(N16W62) WAS NUMBERED.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. REGION 8421 MAY PRODUCE ISOLATED M-CLASS FLARES DURING
THE PERIOD. THERE IS ALSO A CHANCE FOR A MAJOR FLARE FROM THIS
REGION.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 30/2100Z TO 31/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET AT ALL LATITUDES.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT QUIET TO UNSETTLED LEVELS.
III.  EVENT PROBABILITIES 01 JAN-03 JAN
CLASS M    65/65/65
CLASS X    20/20/20
PROTON     15/15/15
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           31 DEC 175
PREDICTED   01 JAN-03 JAN  170/165/165
90 DAY MEAN        31 DEC 136
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 30 DEC  005/006
ESTIMATED AFR/AP 31 DEC  003/010
PREDICTED AFR/AP 01 JAN-03 JAN  007/010-005/010-005/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 01 JAN-03 JAN
A.  MIDDLE LATITUDES
ACTIVE                15/10/10
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                20/15/15
MINOR STORM           10/05/05
MAJOR-SEVERE STORM    01/01/01