:Product: 19990919RSGA.txt
:Issued: 1999 Sep 19 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 262 ISSUED AT 2200Z ON 19 SEP 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  18/2100Z
TO 19/2100Z:  SOLAR ACTIVITY WAS LOW. REGIONS 8699 (N23W78) AND 8700
(N12W05) CONTINUED TO PRODUCE C-CLASS SUBFLARES. THE LARGEST FLARE
OF THE PAST DAY WAS A C4/SF AT 19/1440UT IN REGION 8699. NEITHER
REGION APPEARS SIGNIFICANTLY COMPLEX. NEW REGION 8706 (N19E77)
APPEARS TO BE RETURNING REGION 8681 WHICH LEFT THE DISK LAST
ROTATION AS A DECAYING SUNSPOT GROUP.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. C-CLASS FLARES ARE LIKELY IN REGIONS 8699 AND 8700.
REGION 8700 IS THE BEST CANDIDATE FOR AN ISOLATED M-CLASS FLARE.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 18/2100Z TO 19/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. THE GREATER THAN 2 MEV
ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS HIGH.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO REACH ACTIVE TO STORM LEVELS BY THE END OF SEP 20 DUE TO
A CME/DSF OBSERVED ON SEP 16. THE FIELD SHOULD RETURN TO QUIET TO
UNSETTLED CONDITIONS BY THE END OF THE THREE-DAY FORECAST PERIOD.
III.  EVENT PROBABILITIES 20 SEP-22 SEP
CLASS M    15/15/15
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           19 SEP 149
PREDICTED   20 SEP-22 SEP  146/144/142
90 DAY MEAN        19 SEP 164
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 18 SEP  013/016
ESTIMATED AFR/AP 19 SEP  015/015
PREDICTED AFR/AP 20 SEP-22 SEP  030/030-015/015-010/012
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 20 SEP-22 SEP
A.  MIDDLE LATITUDES
ACTIVE                50/30/20
MINOR STORM           30/10/05
MAJOR-SEVERE STORM    10/05/01
B.  HIGH LATITUDES
ACTIVE                50/30/20
MINOR STORM           30/10/05
MAJOR-SEVERE STORM    10/05/01