:Product: 19990523RSGA.txt
:Issued: 1999 May 23 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 143 ISSUED AT 2200Z ON 23 MAY 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  22/2100Z
TO 23/2100Z:  SOLAR ACTIVITY WAS LOW. THERE WERE EIGHT LOW-LEVEL
C-CLASS EVENTS DURING THE PAST 24 HOURS. OF THE REGIONS ON THE DISK,
8545 (N36W37), 8550 (S14E30), AND 8551 (N33E37) WERE THE MOST
ACTIVE. BOTH REGION 8545 AND 8551 HAVE COMPLICATED INVERSION LINES
BUT RELATIVELY WEAK MAGNETIC STRENGTHS NEAR THE APPARENT SHEAR
POINTS. REGION 8550 IS GROWING SLOWLY AND APPEARED TO BE FORMING A
MODERATE STRENGTH DELTA CONFIGURATION. NEW REGION 8552 (N21E80)
BEGAN TO ROTATE INTO VIEW TODAY WITH THE APPEARANCE OF A LEADER SPOT
WITH MATURE PENUMBRA.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MOSTLY LOW, BUT THERE IS A FAIR CHANCE FOR AN ISOLATED M-CLASS EVENT
SOMETIME DURING THE NEXT THREE DAYS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 22/2100Z TO 23/2100Z:
THE GEOMAGNETIC FIELD RANGED FROM QUIET TO ACTIVE LEVELS. THE GREATER
THAN 2 MEV ELECTRONS ATTAINED HIGH LEVELS DURING THE PAST 24 HOURS
BUT APPEARED TO BE DECREASING TOWARDS NORMAL BACKGROUND LEVELS NEAR
THE END OF THE REPORTING PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE MOSTLY UNSETTLED FOR THE NEXT THREE DAYS. THERE IS AN
ENHANCED POSSIBILITY FOR SOME ACTIVE PERIODS ON THE THIRD DAY DUE TO
RECURRENCE EFFECTS.
III.  EVENT PROBABILITIES 24 MAY-26 MAY
CLASS M    30/30/30
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           23 MAY 141
PREDICTED   24 MAY-26 MAY  143/145/145
90 DAY MEAN        23 MAY 128
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 22 MAY  003/005
ESTIMATED AFR/AP 23 MAY  010/008
PREDICTED AFR/AP 24 MAY-26 MAY  010/012-010/012-015/012
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 24 MAY-26 MAY
A.  MIDDLE LATITUDES
ACTIVE                15/15/25
MINOR STORM           05/05/10
MAJOR-SEVERE STORM    01/01/05
B.  HIGH LATITUDES
ACTIVE                15/15/30
MINOR STORM           10/10/15
MAJOR-SEVERE STORM    05/05/10