:Product: 19991226RSGA.txt
:Issued: 1999 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 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  25/2100Z
TO 26/2100Z:  SOLAR ACTIVITY CONTINUED AT LOW LEVELS. REGION 8806
(N21W41) REMAINED LARGE AND MAGNETICALLY COMPLEX WITH MINOR GROWTH
REPORTED IN THE TRAILER PORTION OF THE REGION. IT PRODUCED ISOLATED,
LOW-LEVEL C-CLASS SUBFLARES DURING THE PERIOD. REGION 8810 (N36E54)
ALSO PRODUCED ISOLATED SUBFLARES, BUT SHOWED NO SIGNIFICANT CHANGES.
IT REMAINED A MODERATE-SIZED E-TYPE REGION WITH A SIMPLE BIPOLAR
STRUCTURE. NO NEW REGIONS WERE ASSIGNED DURING THE PERIOD.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. THERE CONTINUES TO BE A FAIR CHANCE FOR AN ISOLATED
M-CLASS FLARE FROM REGION 8806, AND A SLIGHT CHANCE FOR A MAJOR
FLARE OR PROTON-PRODUCING FLARE.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 25/2100Z TO 26/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT MOSTLY QUIET LEVELS THROUGH THE PERIOD.
III.  EVENT PROBABILITIES 27 DEC-29 DEC
CLASS M    50/50/50
CLASS X    10/10/10
PROTON     10/10/10
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           26 DEC 177
PREDICTED   27 DEC-29 DEC  175/170/170
90 DAY MEAN        26 DEC 175
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 25 DEC  010/010
ESTIMATED AFR/AP 26 DEC  003/005
PREDICTED AFR/AP 27 DEC-29 DEC  007/010-007/007-007/007
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    01/01/01