:Product: 19971106RSGA.txt
:Issued: 1997 Nov 06 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 310 ISSUED AT 2200Z ON 06 NOV 1997
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  05/2100Z
TO 06/2100Z:  SOLAR ACTIVITY WAS HIGH. REGION 8100 (S19W68) PRODUCED
THE LARGEST FLARE YET OF THE NEW SOLAR CYCLE, AN X9/2B PEAKING AT
06/1155Z. THIS FLARE WAS ASSOCIATED WITH RADIO BURSTS OF 54000 SFU
AT 245 MHZ, 3300 SFU AT 2695 MHZ AND A STRONG TYPE IV SWEEP. THE
SUNSPOT GROUP APPEARS TO HAVE SIMPLIFIED SOMEWHAT SINCE THE MAJOR
FLARE, REDUCING PENUMBRAL AREA AND MAGNETIC COMPLEXITY. SUNSPOT
POLARITY DATA SUGGEST THAT THE DELTA CONFIGURATIONS OBSERVED
YESTERDAY ARE NO LONGER PRESENT. CORONAL INSTRUMENTS ON THE SOHO
SATELLITE OBSERVED A "WIDE" (ABOUT 100 DEGREE) CME OFF THE WEST
SOLAR LIMB COINCIDENT WITH THE X-RAY EVENT.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE TO HIGH. THE LIKELIHOOD OF IMMINENT MAJOR FLARES IN REGION
8100 HAS DIMINISHED IN THE WAKE OF TODAY'S MAJOR EVENT. HOWEVER,
THIS REGION IS STILL LARGE AND HAS THE POTENTIAL FOR M-CLASS
ACTIVITY, OR EVEN ANOTHER X-CLASS FLARE, BEFORE IT ROTATES AROUND
THE WEST LIMB IF MAGNETIC ENERGY REGENERATES.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 05/2100Z TO 06/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. THE X-CLASS EVENT
DESCRIBED IN PART IA. PRODUCED PROTON EVENTS AT GREATER THAN 10 AND
100 MEV WHICH REMAIN IN PROGRESS AT THIS TIME. THE GREATER THAN 100
MEV EVENT CROSSED THE EVENT THRESHOLD OF 1 PFU AT 06/1245Z AND
APPEARS TO HAVE REACHED A PEAK FLUX OF 51 PFU AT 06/1640Z. THE
GREATER THAN 10 MEV EVENT CROSSED THE 10 PFU EVENT THRESHOLD AT
06/1305Z AND HAS NOT YET PEAKED (06/2100Z FLUX 340 PFU). THE PCA
ASSOCIATED WITH THIS FLARE BEGAN AT ABOUT 06/1400Z AND REMAINS IN
PROGRESS. CURRENT (06/2100Z) PCA ABSORPTION AT THULE GREENLAND IS
ESTIMATED TO BE 5.6 DB. THIS X9 FLARE PRODUCED THE FIRST GROUND
LEVEL EVENT (GLE) OF THE SOLAR CYCLE (LAST GLE IN 1992). THE GLE
STARTED AT ABOUT 06/1220Z, PEAKED WITH ABOUT A 10% INCREASE ABOVE
BACKGROUND AT 06/1355Z, AND APPEARS TO HAVE ENDED AT 06/2000Z.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO REACH STORM LEVELS BY TOMORROW DUE TO THE MAJOR SOLAR
EVENTS OBSERVED ON 4 NOVEMBER. DISTURBED CONDITIONS SHOULD CONTINUE
FOR THE NEXT FEW DAYS, STARTED BY THE 4 NOV EVENT AND CONTRIBUTED TO
BY TODAY'S SOLAR ACTIVITY.  THIS FORECAST (ACTIVITY DURATION AND
INTENSITY) WILL BE UPDATED AFTER THE GEOMAGNETIC ACTIVITY ONSET.
III.  EVENT PROBABILITIES 07 NOV-09 NOV
CLASS M    50/50/50
CLASS X    05/05/05
PROTON     05/05/05
PCAF       IN PROGRESS
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           06 NOV 105
PREDICTED   07 NOV-09 NOV  100/095/090
90 DAY MEAN        06 NOV 089
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 05 NOV  008/009
ESTIMATED AFR/AP 06 NOV  010/012
PREDICTED AFR/AP 07 NOV-09 NOV  050/060-030/035-020/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 07 NOV-09 NOV
A.  MIDDLE LATITUDES
ACTIVE                30/20/20
MINOR STORM           30/25/20
MAJOR-SEVERE STORM    15/15/10
B.  HIGH LATITUDES
ACTIVE                35/25/25
MINOR STORM           35/30/30
MAJOR-SEVERE STORM    20/20/15