:Product: 19990909RSGA.txt
:Issued: 1999 Sep 09 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 252 ISSUED AT 2200Z ON 09 SEP 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  08/2100Z
TO 09/2100Z:  SOLAR ACTIVITY DECREASED TO LOW LEVELS. REGION 8690
(N13E33) PRODUCED THE SOLE C-CLASS FLARE OF THE PERIOD, A
LONG-DURATION C3/SF AT 09/1637Z ACCOMPANIED BY A 150 SFU TENFLARE
AND A 12 DEGREE FILAMENT DISAPPEARANCE. NO SIGNIFICANT CHANGES WERE
OBSERVED IN ANY OF THE VISIBLE REGIONS DURING THE PERIOD.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO REMAIN
AT LOW LEVELS THROUGHOUT THE PERIOD.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 08/2100Z TO 09/2100Z:
THE GEOMAGNETIC FIELD WAS AT QUIET TO UNSETTLED LEVELS. A WEAK SUDDEN
IMPULSE (05 NT, AS MEASURED BY THE BOULDER USGS MAGNETOMETER)
OCCURRED AT 09/1257Z.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO REMAIN AT QUIET TO UNSETTLED LEVELS DURING THE FIRST
HALF OF THE PERIOD. AN INCREASE TO UNSETTLED TO ACTIVE LEVELS IS
EXPECTED TO OCCUR DURING THE SECOND HALF OF THE PERIOD DUE TO
RECURRENT CORONAL HOLE EFFECTS.
III.  EVENT PROBABILITIES 10 SEP-12 SEP
CLASS M    25/25/25
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           09 SEP 107
PREDICTED   10 SEP-12 SEP  105/100/100
90 DAY MEAN        09 SEP 165
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 08 SEP  005/009
ESTIMATED AFR/AP 09 SEP  009/012
PREDICTED AFR/AP 10 SEP-12 SEP  010/015-012/015-015/012
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 10 SEP-12 SEP
A.  MIDDLE LATITUDES
ACTIVE                20/30/35
MINOR STORM           05/05/10
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                25/35/40
MINOR STORM           05/10/15
MAJOR-SEVERE STORM    01/01/05