:Product: 20000517RSGA.txt
:Issued: 2000 May 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 138 ISSUED AT 2200Z ON 17 MAY 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  16/2100Z
TO 17/2100Z:  SOLAR ACTIVITY WAS LOW. THE MOST ACTIVE REGIONS WERE
8996 (S21E03), 8998 (N20E17), AND 9002 (N18E48), ALL OF WHICH
PRODUCED ISOLATED C-CLASS X-RAY EVENTS AND OPTICAL SUBFLARES.
REGIONS 8996 AND 9002 CONTINUE TO BE THE LARGEST REGIONS ON THE
DISK, WITH AREAS OF 1280 AND 820 MILLIONTHS, AND SPOT COUNTS OF 53
AND 29 RESPECTIVELY. A 29 DEGREE LONG, DISAPPEARING SOLAR FILAMENT
(DSF) OCCURRED DURING THE PERIOD 17/1808-1843UT, NEAR S22W37. FOUR
NEW REGIONS WERE NUMBERED DURING THE PERIOD: 9005 (S18W56), 9006
(N26W88), 9007 (S42E12), AND 9008 (S13E50).
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE. REGIONS 8996, 8998, AND 9002 ARE ALL CAPABLE OF PRODUCING
M-CLASS EVENTS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 16/2100Z TO 17/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE WITH MINOR STORMING
OCCURRING DURING THE PERIOD 17/03-0900UT AT MID-LATITUDES AND
17/00-0900UT AT HIGHER LATITUDES.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED IS EXPECTED TO BE UNSETTLED TO ACTIVE WITH POSSIBLE MINOR
STORMING AT HIGH LATITUDES FOR THE FIRST DAY OF THE PERIOD. THIS
INCREASED ACTIVITY WOULD BE THE RESULT OF INTERACTION WITH A CME
REPORTED ON 15 MAY. CONDITIONS SHOULD BE UNSETTLED TO ACTIVE ON THE
SECOND DAY AND QUIET TO UNSETTLED ON THE THIRD.
III.  EVENT PROBABILITIES 18 MAY-20 MAY
CLASS M    80/80/80
CLASS X    15/15/15
PROTON     10/10/10
PCAF       YELLOW
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           17 MAY 262
PREDICTED   18 MAY-20 MAY  260/260/265
90 DAY MEAN        17 MAY 191
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 16 MAY  014/018
ESTIMATED AFR/AP 17 MAY  021/023
PREDICTED AFR/AP 18 MAY-20 MAY  025/030-018/020-015/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 18 MAY-20 MAY
A.  MIDDLE LATITUDES
ACTIVE                50/30/25
MINOR STORM           20/15/10
MAJOR-SEVERE STORM    10/05/05
B.  HIGH LATITUDES
ACTIVE                70/35/30
MINOR STORM           20/20/15
MAJOR-SEVERE STORM    10/05/05