:Product: 19991117RSGA.txt
:Issued: 1999 Nov 17 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 321 ISSUED AT 2200Z ON 17 NOV 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  16/2100Z
TO 17/2100Z:  SOLAR ACTIVITY WAS HIGH.  TWO M-CLASS X-RAY FLARES WERE
OBSERVED.  THE LARGEST, AN M7/2B FLARE FROM REGION 8766 (N17E21),
OCCURRED AT 0957Z.  TYPE II AND IV RADIO SWEEPS, A 390 SFU TENFLARE,
AND OTHER DISCRETE RADIO BURSTS ACCOMPANIED THIS EVENT.  THE SECOND
FLARE, AN M2/1N FROM REGION 8765 (S11E08), PEAKED AT 16/2124Z.  THE
REMAINDER OF THE PERIOD SAW NUMEROUS C-CLASS SUBFLARES SUPERIMPOSED
ON AN ELEVATED BACKGROUND FLUX LEVEL OF NEARLY C2.  REGION 8765
ATTAINED A WHITE-LIGHT AREA OF 1190 MILLIONTHS AND REMAINS A
BETA-GAMMA-DELTA GROUP.  NEW REGION 8771 (S14W33) WAS NUMBERED
TODAY.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE TO HIGH. BOTH REGIONS 8765 AND 8766 HAVE THE POTENTIAL TO
GENERATE A MAJOR PROTON PRODUCING FLARE WITHIN THE NEXT FEW DAYS.
ISOLATED M-CLASS ACTIVITY IS ALSO POSSIBLE FROM REGION 8768.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 16/2100Z TO 17/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED FOR THE FIRST DAY OF THE PERIOD.
BY DAYS TWO AND THREE ACTIVE TO MINOR STORM CONDITIONS ARE POSSIBLE
DUE TO CME EFFECTS.  PARTIAL HALO CMES WERE OBSERVED ON SOHO/LASCO
IMAGERY YESTERDAY AND TODAY'S FLARE ACTIVITY PRODUCED RADIO CME
SIGNATURES.
III.  EVENT PROBABILITIES 18 NOV-20 NOV
CLASS M    90/90/90
CLASS X    30/30/30
PROTON     15/15/15
PCAF       YELLOW
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           17 NOV 221
PREDICTED   18 NOV-20 NOV  215/200/195
90 DAY MEAN        17 NOV 165
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 16 NOV  011/016
ESTIMATED AFR/AP 17 NOV  011/016
PREDICTED AFR/AP 18 NOV-20 NOV  012/012-020/020-020/020
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 18 NOV-20 NOV
A.  MIDDLE LATITUDES
ACTIVE                35/45/45
MINOR STORM           10/20/20
MAJOR-SEVERE STORM    05/10/10
B.  HIGH LATITUDES
ACTIVE                40/50/50
MINOR STORM           20/25/25
MAJOR-SEVERE STORM    10/10/10