:Product: 19991217RSGA.txt
:Issued: 1999 Dec 17 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 351 ISSUED AT 2200Z ON 17 DEC 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  16/2100Z
TO 17/2100Z:  SOLAR ACTIVITY WAS LOW. REGION 8798 (S13E21) PRODUCED
SEVERAL C-CLASS X-RAY EVENTS DURING THE PERIOD. THE LASCO SPACECRAFT
OBSERVED A CME CORRESPONDING WITH A C4/1F AT 17/0935Z FROM REGION
8798. THIS REGION REMAINS THE LARGEST REGION ON THE SOLAR DISK WITH
AN AREA OF 550 MILLIONTHS AND CONTAINS A DKC BETA-GAMMA-DELTA SPOT
GROUP. REGION 8803 (S13E10) PRODUCED A LONG DURATION C1/SF AT
17/1750Z. TWO NEW REGIONS WERE NUMBERED TODAY AS REGION 8805
(N18W27) AND REGION 8806 (N18E71).
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.
REGION 8798 CONTINUES TO HAVE THE POTENTIAL TO PRODUCE AN ISOLATED
M-CLASS EVENT THROUGH THE PERIOD.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 16/2100Z TO 17/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED THROUGH THE FORECAST PERIOD.
III.  EVENT PROBABILITIES 18 DEC-20 DEC
CLASS M    40/40/40
CLASS X    10/10/10
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           17 DEC 201
PREDICTED   18 DEC-20 DEC  210/195/190
90 DAY MEAN        17 DEC 169
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 16 DEC  006/005
ESTIMATED AFR/AP 17 DEC  008/008
PREDICTED AFR/AP 18 DEC-20 DEC  008/008-008/010-010/012
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 18 DEC-20 DEC
A.  MIDDLE LATITUDES
ACTIVE                10/10/10
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                10/15/15
MINOR STORM           05/10/10
MAJOR-SEVERE STORM    01/05/05