:Product: 19990124RSGA.txt
:Issued: 1999 Jan 24 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 024 ISSUED AT 2200Z ON 24 JAN 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  23/2100Z
TO 24/2100Z:  SOLAR ACTIVITY WAS LOW. THE LARGEST EVENT OF THE PERIOD
WAS A C5/SF FLARE FROM REGION 8444 (N20W38) AT 24/0820Z. A MORE
INTERESTING EVENT WAS A GRADUAL RISE AND FALL C3 X-RAY EVENT FROM
24/1555-1920Z. A REPORT WAS RECEIVED OF CORONAL RAIN AND A WEAK LOOP
PROMINENCE SYSTEM VISIBLE NEAR SW28 TOWARD THE END OF THE X-RAY
EVENT. NO SIGNIFICANT FLARE WAS OBSERVED IN NEARBY REGION 8439
(S23W81) DURING THE EVENT BUT, IN MOVIE SEQUENCES, FIBRIL DISTORTIONS
WERE. IT IS LIKELY THAT A FILAMENT ERUPTED BEHIND THE WEST LIMB AND
SOME MATERIAL FLOWED DOWN ALONG FIELD LINES NEAR REGION 8439.
REGIONS 8439 AND 8440 (N19W78) SHOWED SLIGHT DECAY BUT THAT MAY BE
DUE IN PART TO FORESHORTENING.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD BE PREDOMINANTLY
LOW FOR THE NEXT THREE DAYS DUE TO SUBFLARES FROM REGIONS 8439,
8440, AND 8444. REGIONS 8439 AND 8440 REMAIN CAPABLE OF PRODUCING
ISOLATED M-CLASS EVENTS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 23/2100Z TO 24/2100Z:
DURING THE FIRST HALF OF THE PERIOD, THE GEOMAGNETIC FIELD WAS AT
UNSETTLED TO ACTIVE LEVELS. QUIET TO UNSETTLED CONDITIONS WERE
OBSERVED DURING THE LATTER HALF. THE GT 10 MEV PROTON FLUX REMAINED
ENHANCED BUT BELOW EVENT LEVEL FOR THE ENTIRE PERIOD. A FORBUSH
DECREASE BEGAN EARLY ON 23 JAN. THE NEUTRON FLUX DURING THE EVENT
WAS DEPRESSED BY APPROXIMATELY 6 PERCENT NEAR MIDDAY ON 24 JAN. AT
THE END OF THE PERIOD, THE FORBUSH DECREASE WAS SLOWLY RECOVERING TO
NORMAL VALUES.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD BE
QUIET TO UNSETTLED FOR THE NEXT THREE DAYS. THE GT 10 MEV PROTON
FLUX SHOULD RETURN TO BACKGROUND LEVELS DURING THE PERIOD.
III.  EVENT PROBABILITIES 25 JAN-27 JAN
CLASS M    40/20/15
CLASS X    10/05/05
PROTON     10/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           24 JAN 162
PREDICTED   25 JAN-27 JAN  153/142/137
90 DAY MEAN        24 JAN 143
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 23 JAN  017/016
ESTIMATED AFR/AP 24 JAN  013/015
PREDICTED AFR/AP 25 JAN-27 JAN  008/010-008/010-010/008
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 25 JAN-27 JAN
A.  MIDDLE LATITUDES
ACTIVE                15/10/15
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                20/15/15
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01