:Product: 19981226RSGA.txt
:Issued: 1998 Dec 26 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 360 ISSUED AT 2200Z ON 26 DEC 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  25/2100Z
TO 26/2100Z:  SOLAR ACTIVITY WAS LOW. SEVERAL C-CLASS EVENTS OCCURRED
DURING THE PERIOD. REGION 8419 (N27W14) PRODUCED TWO, REGION 8421
(N26E40) PRODUCED THREE, REGION 8422 (S23E51) WAS RESPONSIBLE FOR
ONE, AND ONE WERE OPTICALLY UNCORRELATED. THE LARGEST REGION ON THE
DISK IS REGION 8421 WHICH IS A DAI BETA GROUP WITH AN AREA OF 270
MILLIONTHS.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE THROUGH THE PERIOD. SEVERAL REGIONS HAVE THE POTENTIAL
OF PRODUCING ISOLATED M-CLASS EVENTS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 25/2100Z TO 26/2100Z:
THE GEOMAGNETIC FIELD WAS AT QUIET TO MINOR STORM CONDITIONS. THESE
CONDITIONS MAY HAVE BEEN THE RESULT OF THE LONG DURATION M2 WITH AN
ASSOCIATED TYPE II AND TYPE IV RADIO SWEEP THAT OCCURRED JUST BEHIND
THE NORTH EAST LIMB ON 23 DECEMBER AT 0659Z.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED THROUGH THE FORECAST PERIOD.
III.  EVENT PROBABILITIES 27 DEC-29 DEC
CLASS M    30/30/30
CLASS X    05/05/05
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           26 DEC 145
PREDICTED   27 DEC-29 DEC  150/154/154
90 DAY MEAN        26 DEC 133
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 25 DEC  009/011
ESTIMATED AFR/AP 26 DEC  020/015
PREDICTED AFR/AP 27 DEC-29 DEC  005/012-005/009-005/012
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 27 DEC-29 DEC
A.  MIDDLE LATITUDES
ACTIVE                10/10/10
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                15/15/15
MINOR STORM           10/10/10
MAJOR-SEVERE STORM    05/05/05