:Product: 19990125RSGA.txt
:Issued: 1999 Jan 25 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 025 ISSUED AT 2200Z ON 25 JAN 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  24/2100Z
TO 25/2100Z:  SOLAR ACTIVITY BECAME MODERATE. REGION 8444 (N20W51)
PRODUCED AN IMPULSIVE M2/SN AT 25/0056Z WITH MODERATE RADIO BURSTS
IN THE 245-606 MHZ RANGE. THIS EVENT WAS PRECEDED BY A LONG DURATION
C3/SF AT 25/0012Z FROM REGION 8444. THIS EVENT PRODUCED A MODERATE
INTENSITY TYPE II RADIO BURST. REGION 8444 ALSO PRODUCED A C8/SF AT
25/1407Z. THIS REGION EXHIBITED SLIGHT GROWTH DURING THE PERIOD. ITS
FLARE PRODUCTION RATE BELIES ITS SMALL SIZE AND RELATIVE STABILITY
IN WHITE LIGHT. IT IS LIKELY THERE ARE MIXED POLARITIES IN THIS
REGION BUT THE LACK OF MAGNETOGRAPH DATA PREVENTED VERIFICATION.
REGIONS 8439 (S23W93) AND 8440 (N19W87) MAY HAVE PRODUCED SEVERAL
SMALL X-RAY ENHANCEMENTS.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
PREDOMINANTLY LOW. REGION 8444 IS OBVIOUSLY CAPABLE OF GENERATING
OCCASIONAL SMALL M-CLASS EVENTS. HOWEVER, ANY SIMPLIFICATION IN THIS
SMALL REGION COULD RESULT IN THE CESSATION OF FLARE PRODUCTION.
REGIONS 8439 AND 8440 REMAIN CAPABLE OF PRODUCING OCCASIONAL M-CLASS
FLARES. THIS IS A PERSISTENCE FORECAST DUE TO THE FORESHORTENING OF
THESE REGIONS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 24/2100Z TO 25/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. SOLAR WIND VELOCITIES
DECREASED DURING THE PERIOD. THE GT 10 MEV PROTON ENHANCEMENT
CONTINUED SLIGHTLY ABOVE BACKGROUND. THE FORBUSH DECREASE THAT BEGAN
ON 23 JAN CONTINUED TO SLOWLY RECOVER.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED FOR THE NEXT THREE DAYS. BRIEF
PERIODS OF ACTIVE CONDITIONS ARE POSSIBLE TOWARD THE END OF THE
PERIOD IN RESPONSE TO A THIN TRANSEQUATORIAL CORONAL HOLE THAT
PASSED CENTRAL MERIDIAN ON 24 JAN.
III.  EVENT PROBABILITIES 26 JAN-28 JAN
CLASS M    45/30/20
CLASS X    10/05/05
PROTON     10/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           25 JAN 138
PREDICTED   26 JAN-28 JAN  125/120/118
90 DAY MEAN        25 JAN 144
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 24 JAN  011/013
ESTIMATED AFR/AP 25 JAN  009/010
PREDICTED AFR/AP 26 JAN-28 JAN  008/010-010/010-010/008
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 26 JAN-28 JAN
A.  MIDDLE LATITUDES
ACTIVE                10/15/15
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                10/15/15
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01