:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Apr 17 2200 UT
# 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 108 ISSUED AT 2200Z ON 17 APR 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  16/2100Z
TO 17/2100Z:  SOLAR ACTIVITY WAS LOW. REGION 8955 (S22W06) PRODUCED
THE TWO LARGEST EVENTS OF THE PERIOD - A C2/1F AT 17/0028UT AND A
C3/1N AT 17/1734UT. THIS REGION APPEARS TO HAVE STABILIZED,
EXHIBITING LITTLE CHANGE OVER THE PAST 24 HOURS AND NOW COVERS 320
MILLIONTHS OF WHITE LIGHT AREA. THERE WAS LITTLE OR NO CHANGE OR
ACTIVITY NOTED IN THE REMAINING ELEVEN SPOTTED REGIONS. NEW REGION
8965 (S16E66) WAS NUMBERED TODAY.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. REGION 8955 STILL HAS POTENTIAL FOR AN ISOLATED SMALL
M-CLASS FLARE.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 16/2100Z TO 17/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE WITH AN ISOLATED MINOR
STORMING PERIOD BETWEEN 17/06 - 09UT.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE MOSTLY QUIET TO UNSETTLED WITH ISOLATED ACTIVE
PERIODS THROUGH THE NEXT THREE DAYS.
III.  EVENT PROBABILITIES 18 APR-20 APR
CLASS M    50/50/50
CLASS X    05/05/05
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           17 APR 158
PREDICTED   18 APR-20 APR  160/165/165
90 DAY MEAN        17 APR 183
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 16 APR  016/023
ESTIMATED AFR/AP 17 APR  012/015
PREDICTED AFR/AP 18 APR-20 APR  012/015-012/012-012/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 18 APR-20 APR
A.  MIDDLE LATITUDES
ACTIVE                35/30/25
MINOR STORM           15/15/10
MAJOR-SEVERE STORM    05/05/01
B.  HIGH LATITUDES
ACTIVE                45/40/30
MINOR STORM           25/25/15
MAJOR-SEVERE STORM    10/10/05