:Product: 19990725RSGA.txt
:Issued: 1999 Jul 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 206 ISSUED AT 2200Z ON 25 JUL 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  24/2100Z
TO 25/2100Z:  SOLAR ACTIVITY WAS MODERATE. REGION 8639 (N38W86)
PRODUCED A MODERATE DURATION M2/SF AT 25/1338Z. THIS EVENT WAS
ACCOMPANIED BY TYPE II/IV SWEPT FREQUENCY BURSTS, A 600 SFU BURST AT
10 CM, AND A LOOP PROMINENCE SYSTEM. DUE TO FORESHORTENING, LITTLE
IS KNOWN ABOUT THE EVOLUTION OF THIS REGION. REGION 8645 (S27E60)
GENERATED AN M1/1F AT 25/0432Z. THIS REGION APPEARED AS A MODERATE
SIZE F CLASS GROUP. IT IS LIKELY THAT THERE IS SOME MAGNETIC
COMPLEXITY IN THIS AREA. REGION 8636 (N21W27) GENERATED A C8/SF AT
25/0103Z. MAGNETIC FIELD MIXING INCREASED SLIGHTLY IN THIS REGION
AND SPOT AREA INCREASED IN THE LEADER.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD CONTINUE AT A
MODERATE LEVEL FOR THE NEXT THREE DAYS WITH M-CLASS EVENTS POSSIBLE
FROM REGIONS 8645, 8636, AND 8639. AN ISOLATED X-CLASS EVENT IS
POSSIBLE FROM REGION 8636 OR 8645.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 24/2100Z TO 25/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. SOLAR WIND VELOCITY
DROPPED TO NORMAL VALUES DURING THE PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE PREDOMINANTLY QUIET TO UNSETTLED FOR THE NEXT THREE
DAYS. AT HIGH LATITUDES, SOME ACTIVE CONDITIONS MAY BE EXPERIENCED
ON 28 JUL. THERE IS A SLIGHT POSSIBILITY THAT A MAJOR FLARE FROM
REGION 8636 COULD CAUSE AN ENERGETIC SOLAR PROTON EVENT AT EARTH.
III.  EVENT PROBABILITIES 26 JUL-28 JUL
CLASS M    90/90/90
CLASS X    20/20/20
PROTON     20/20/20
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           25 JUL 182
PREDICTED   26 JUL-28 JUL  180/182/184
90 DAY MEAN        25 JUL 157
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 24 JUL  008/011
ESTIMATED AFR/AP 25 JUL  008/012
PREDICTED AFR/AP 26 JUL-28 JUL  008/007-008/007-008/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 26 JUL-28 JUL
A.  MIDDLE LATITUDES
ACTIVE                10/10/10
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                10/10/20
MINOR STORM           05/05/10
MAJOR-SEVERE STORM    01/01/05