:Product: 19990920RSGA.txt
:Issued: 1999 Sep 20 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 263 ISSUED AT 2200Z ON 20 SEP 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  19/2100Z
TO 20/2100Z:  SOLAR ACTIVITY WAS LOW. REGION 8699 (N24W88) PRODUCED
THE LARGEST FLARE, A C9/1F AT 19/2312UT. REGION 8700 (N12W19) ALSO
PRODUCED SMALL C-CLASS FLARES.  REGION 8700 CONTINUES TO SLOWLY
DECAY. REMAINING DISK REGIONS ARE SMALL AND SIMPLE.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. C-CLASS ACTIVITY IS EXPECTED TO CONTINUE, PRIMARILY IN
REGION 8700. THE LIKELIHOOD OF M-CLASS ACTIVITY IS DIMINISHING WITH
THE DEPARTURE OF REGION 8699 AND THE DECAY IN REGION 8700.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 19/2100Z TO 20/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. THE GREATER THAN 2 MEV
ELECTRON FLUX WAS MODERATE TO HIGH.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED. A SOLAR WIND SIGNATURE FROM THE
SEP 16 CME/DSF EVENT HAS NOT YET BEEN SEEN AND ITS ARRIVAL IS
BECOMING LESS LIKELY.
III.  EVENT PROBABILITIES 21 SEP-23 SEP
CLASS M    10/10/10
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           20 SEP 145
PREDICTED   21 SEP-23 SEP  142/140/138
90 DAY MEAN        20 SEP 164
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 19 SEP  009/010
ESTIMATED AFR/AP 20 SEP  010/010
PREDICTED AFR/AP 21 SEP-23 SEP  010/015-010/012-010/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 21 SEP-23 SEP
A.  MIDDLE LATITUDES
ACTIVE                20/10/05
MINOR STORM           05/01/01
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                20/10/10
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01