:Product: 19981217RSGA.txt
:Issued: 1998 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 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  16/2100Z
TO 17/2100Z:  SOLAR ACTIVITY WAS MODERATE WITH SEVERAL C-CLASS X-RAY
EVENTS AND ONE ISOLATED M-CLASS X-RAY FLARE DURING THE PERIOD.
REGION 8409 (S28W52) PRODUCED A M3/1N EVENT AT 17/0745Z WITH AN
ASSOCIATED TYPE II SWEEP.  THE TYPE II SPEED WAS ESTIMATED AT 500
KM/S.  A 230 SFU TENFLARE WAS ALSO DETECTED DURING THE M3 EVENT.  AT
17/1418Z, REGION 8409 PRODUCED A C7/SN EVENT.  AN ASSOCIATED TYPE II
SWEEP WITH AN ESTIMATED SPEED OF 600 KM/S WAS OBSERVED.  REGION 8415
(N19E70) WAS NUMBERED AND IS CURRENTLY A BXO BETA SPOT GROUP WITH
SEVEN SPOTS.  AT 17/1753Z, REGION 8415 PRODUCED A C6/1F EVENT.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
WITH CONTINUED C-CLASS EVENTS.  THERE IS A CHANCE FOR AN ISOLATED
M-CLASS X-RAY EVENT OUT OF REGION 8409.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 16/2100Z TO 17/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET.  NO FURTHER AFFECTS WERE OBSERVED
FROM THE CORONAL HOLE IN THE NORTHERN HEMISPHERE DURING THE PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET DURING THE FIRST DAY OF THE PERIOD BECOMING
QUIET TO UNSETTLED DURING THE LAST TWO DAYS OF THE PERIOD.
III.  EVENT PROBABILITIES 18 DEC-20 DEC
CLASS M    25/25/25
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           17 DEC 146
PREDICTED   18 DEC-20 DEC  145/140/135
90 DAY MEAN        17 DEC 133
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 16 DEC  009/011
ESTIMATED AFR/AP 17 DEC  001/002
PREDICTED AFR/AP 18 DEC-20 DEC  005/009-008/009-008/009
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 18 DEC-20 DEC
A.  MIDDLE LATITUDES
ACTIVE                10/10/10
MINOR STORM           01/01/01
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                15/15/15
MINOR STORM           01/01/01
MAJOR-SEVERE STORM    01/01/01