:Product: 19991121RSGA.txt
:Issued: 1999 Nov 21 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 325 ISSUED AT 2200Z ON 21 NOV 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  20/2100Z
TO 21/2100Z:  SOLAR ACTIVITY INCREASED TO MODERATE LEVELS. REGION
8765 (S12W60) PRODUCED THREE M-CLASS FLARES, AN M1/1N AT 21/0014Z
ASSOCIATED WITH A 280 SFU TENFLARE, AN M2/SN AT 21/1017Z, AND AN
M3/2N AT 21/1820Z ASSOCIATED WITH A 270 SFU TENFLARE. THIS REGION
SHOWED A SLIGHT DECREASE IN MAGNETIC FIELD INTENSITY, BUT REMAINED
LARGE AND STRUCTURALLY COMPLEX, POSSIBLY INCLUDING A MAGNETIC DELTA
CONFIGURATION WITHIN ITS INTERIOR SPOTS. REGION 8771 (S16E01) SHOWED
A MAGNETIC DELTA CONFIGURATION WITHIN ITS TRAILER PORTION AND
UNDERWENT MINOR DEVELOPMENT. IT PRODUCED AN M3/2B FLARE AT 20/2235Z
ASSOCIATED WITH A TYPE II RADIO SWEEP (EST. VELOCITY 700 KM/SEC).
REGION 8768 (N16W65) SHOWED A MINOR INCREASE IN SPOT COUNT DURING
THE PERIOD AND PRODUCED ISOLATED SUBFLARES, NONE OF WHICH WERE
ASSOCIATED WITH SIGNIFICANT X-RAY EMISSION. REGION 8766 (N18W36)
DECAYED SLIGHTLY. THE REMAINING REGIONS WERE SMALL AND STABLE
INCLUDING NEWLY NUMBERED REGIONS 8777 (S26E40) AND 8778 (S14E62).
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO REMAIN
AT MODERATE LEVELS. REGIONS 8765 AND 8771 ARE EXPECTED TO PRODUCE
M-CLASS FLARES. THERE IS ALSO A CHANCE FOR A MAJOR FLARE, ESPECIALLY
FROM REGION 8765.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 20/2100Z TO 21/2100Z:
GEOMAGNETIC FIELD ACTIVITY RANGED FROM QUIET TO MINOR STORM LEVELS. A
BRIEF PERIOD OF ACTIVE TO MINOR STORM LEVELS OCCURRED AROUND
21/0600Z FOLLOWING A 3-HOUR PERIOD OF SUSTAINED SOUTHWARD IMF BZ.
THE GEOMAGNETIC FIELD WAS AT QUIET TO UNSETTLED LEVELS DURING THE
REST OF THE PERIOD. THE GREATER THAN 2 MEV ELECTRON FLUX BRIEFLY
REACHED HIGH LEVELS LATE IN THE PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  GEOMAGNETIC FIELD ACTIVITY IS
EXPECTED TO RANGE FROM QUIET TO ACTIVE LEVELS. ACTIVE LEVELS ARE
POSSIBLE DURING 23 NOVEMBER DUE TO CORONAL HOLE EFFECTS. THE GREATER
THAN 2 MEV ELECTRON FLUX IS EXPECTED TO BE AT MODERATE TO HIGH
LEVELS.
III.  EVENT PROBABILITIES 22 NOV-24 NOV
CLASS M    80/80/80
CLASS X    20/20/20
PROTON     15/15/15
PCAF       YELLOW
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           21 NOV 210
PREDICTED   22 NOV-24 NOV  195/185/170
90 DAY MEAN        21 NOV 167
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 20 NOV  007/009
ESTIMATED AFR/AP 21 NOV  015/010
PREDICTED AFR/AP 22 NOV-24 NOV  012/015-015/018-012/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 22 NOV-24 NOV
A.  MIDDLE LATITUDES
ACTIVE                25/35/25
MINOR STORM           10/15/10
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                30/40/30
MINOR STORM           15/20/15
MAJOR-SEVERE STORM    01/01/01