:Product: 19981228RSGA.txt
:Issued: 1998 Dec 28 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 362 ISSUED AT 2200Z ON 28 DEC 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  27/2100Z
TO 28/2100Z:  SOLAR ACTIVITY WAS MODERATE. REGION 8419 (N26W40)
PRODUCED AN M3/1B FLARE AT 0548UT. THIS GROUP HAS CONTINUED TO GROW
RAPIDLY, NEARLY DOUBLING IN SIZE OVER THE LAST 24 HOURS. THE SPOTS
ARE RATHER COMPACT AND SHOW THE PRESENCE OF A MAGNETIC DELTA
CONFIGURATION. THE GROUP ALSO PRODUCED NUMEROUS C-CLASS FLARES
DURING THE REPORTING PERIOD. REGION 8421 (N26E13) PRODUCED AN M1/SF
AT 0521Z. THIS REGION CONTINUES TO BE LARGE AND MAGNETICALLY
COMPLEX, ALTHOUGH REGION 8421'S GROWTH RATE IS MUCH SLOWER THAN THAT
OF REGION 8419.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE DUE TO THE LIKELIHOOD OF AN M-CLASS FLARE FROM EITHER
REGION 8419 OR 8421. THERE IS A SLIGHT CHANCE FOR A MAJOR FLARE
EVENT FROM THESE REGIONS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 27/2100Z TO 28/2100Z:
THE GEOMAGNETIC FIELD WAS MOSTLY QUIET FOR THE PAST 24 HOURS.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TOMORROW AND QUIET TO UNSETTLED FOR THE
SECOND AND THIRD DAYS.
III.  EVENT PROBABILITIES 29 DEC-31 DEC
CLASS M    70/70/70
CLASS X    15/15/15
PROTON     15/15/15
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           28 DEC 184
PREDICTED   29 DEC-31 DEC  185/180/175
90 DAY MEAN        28 DEC 134
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 27 DEC  001/003
ESTIMATED AFR/AP 28 DEC  003/009
PREDICTED AFR/AP 29 DEC-31 DEC  010/011-005/009-005/009
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 29 DEC-31 DEC
A.  MIDDLE LATITUDES
ACTIVE                15/10/10
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                15/10/10
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01