:Product: 19990126RSGA.txt
:Issued: 1999 Jan 26 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 026 ISSUED AT 2200Z ON 26 JAN 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  25/2100Z
TO 26/2100Z:  SOLAR ACTIVITY RETURNED TO A LOW LEVEL. THE LARGEST
EVENT WAS AN IMPULSIVE C7/1N FROM REGION 8447 (N19W72) AT 26/1844Z
THAT WAS ACCOMPANIED BY MINOR RADIO BURSTS. REGION 8447 IS A SMALL
SPOT GROUP VERY NEAR PREVIOUSLY ACTIVE REGION 8444 (N19W66). REGION
8444 EXHIBITED DECAY DURING THE PERIOD. RECENT MAGNETIC DATA SHOW
SOME MIXED MAGNETIC FIELDS IN THIS SMALL COMPLEX OF REGIONS. A
MODERATE DURATION C5 X-RAY EVENT OCCURRED AT 26/1121Z. AN OBSERVER
REPORTED FAINT CORONAL RAIN BEHIND THE WEST LIMB AT SW25 NEAR THE
END OF THIS X-RAY FLARE. IT IS LIKELY THIS EVENT ORIGINATED FROM
REGION 8439 WHICH IS ONE DAY BEYOND THE WEST LIMB AT THAT LATITUDE.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD REMAIN AT
PREDOMINANTLY LOW LEVELS FOR THE NEXT TWO DAYS WITH REGIONS 8444 AND
8447 PRODUCING OCCASIONAL C-CLASS EVENTS AND POSSIBLY AN ISOLATED
M-CLASS FLARE. VERY LOW LEVELS ARE EXPECTED TO BEGIN ON 29 JAN WHEN
THESE REGIONS ROTATE OFF THE DISK. A FILAMENT LOCATED NEAR N31 AT
THE CENTRAL MERIDIAN COULD ERUPT DURING ITS DISK TRANSIT. A LONG
DURATION C OR M-CLASS EVENT WITH A LARGE CORONAL MASS EJECTION COULD
RESULT SHOULD THE ERUPTION OCCUR.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 25/2100Z TO 26/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET. SOLAR WIND VELOCITIES CONTINUED TO
DECREASE. THE GT 10 MEV PROTON ENHANCEMENT CONTINUED TO DECLINE AND
WAS VERY NEAR BACKGROUND LEVEL AT THE END OF THE PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO SLIGHTLY UNSETTLED FOR THE NEXT THREE DAYS.
III.  EVENT PROBABILITIES 27 JAN-29 JAN
CLASS M    20/20/05
CLASS X    10/05/01
PROTON     10/05/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           26 JAN 133
PREDICTED   27 JAN-29 JAN  123/118/112
90 DAY MEAN        26 JAN 144
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 25 JAN  006/009
ESTIMATED AFR/AP 26 JAN  005/010
PREDICTED AFR/AP 27 JAN-29 JAN  010/010-010/008-010/007
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 27 JAN-29 JAN
A.  MIDDLE LATITUDES
ACTIVE                10/10/10
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                15/15/15
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01