:Product: 19991222RSGA.txt
:Issued: 1999 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 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  21/2100Z
TO 22/2100Z:  SOLAR ACTIVITY WAS HIGH. REGION 8806 (N19E12) PRODUCED
AN IMPULSIVE M5/1B FLARE AT 1904Z. THIS REGION WAS QUITE ACTIVE
DURING THE PERIOD AND SHOWS A COMPLEX INVERSION LINE WITH SOME
EVIDENCE FOR SHEARED MAGNETIC FIELDS. THE MAGNETIC DELTA
CONFIGURATION PERSISTED THROUGH MOST OF THE DAY BUT MAY BE BREAKING
UP AS OF FORECAST FILE TIME. AN ADDITIONAL M-CLASS EVENT OCCURRED
TODAY AT 0216Z. THIS EVENT WAS COMPLICATED IN THAT IT STARTED WITH
AN ERUPTING FILAMENT, FOLLOWED BY EVENT LEVEL FLARES IN 8807
(N10E16) AND 8806. REGION 8798 (S13W47) SHOWED SOME DECAY TODAY AND
EXHIBITED FREQUENT PLAGE FLUCTUATIONS, BUT DID NOT PRODUCE
SIGNIFICANT FLARE ACTIVITY.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE. REGIONS 8798 AND 8806 ARE BOTH GOOD CANDIDATES FOR
PRODUCING ADDITIONAL M-FLARES. THERE IS A FAIR CHANCE FOR AN
ISOLATED MAJOR FLARE EVENT FROM REGION 8806 OVER THE NEXT THREE
DAYS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 21/2100Z TO 22/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE MOSTLY QUIET FOR THE NEXT THREE DAYS.
III.  EVENT PROBABILITIES 23 DEC-25 DEC
CLASS M    75/75/75
CLASS X    20/20/20
PROTON     10/10/10
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           22 DEC 202
PREDICTED   23 DEC-25 DEC  200/200/195
90 DAY MEAN        22 DEC 173
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 21 DEC  001/002
ESTIMATED AFR/AP 22 DEC  001/003
PREDICTED AFR/AP 23 DEC-25 DEC  005/007-005/007-005/007
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 23 DEC-25 DEC
A.  MIDDLE LATITUDES
ACTIVE                15/15/15
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                15/15/15
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01