NOAA/USAF Report of Solar-Geophysical Activity 16 September 2000

:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Sep 16 2200 UT
# 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 260 ISSUED AT 2200Z ON 16 SEP 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  15/2100Z
TO 16/2100Z:  SOLAR ACTIVITY WAS HIGH. REGION 9165 (N13W14) PRODUCED
AN M5/2B AT 16/0426 UTC. THIS FLARE WAS ASSOCIATED WITH TYPE II AND
IV SWEEPS AND AN 1100 SFU RADIO BURST AT 2695 MHZ. IN ADDITION, THE
LASCO INSTRUMENT ON THE SOHO SPACECRAFT OBSERVED AN EARTH-DIRECTED
CME FOLLOWING THIS FLARE.  REGION 9165 ALSO PRODUCED AN M3/2N AT
16/1428 UTC AS WELL AS SEVERAL C-CLASS FLARES. THIS REGION REMAINS
THE LARGEST AND MOST COMPLEX ON THE VISIBLE DISK BUT HAS SHOWN SOME
PENUMBRAL DECAY AND MAGNETIC SIMPLIFICATION SINCE YESTERDAY. REGION
9166 (S14E50) CONTINUED TO GENERATE SMALL C-CLASS FLARES. THIS
REGION HAS UNDERGONE SOME GROWTH IN SPOT AREA AND NUMBER SINCE
YESTERDAY. NEW REGION 9167 (N12E80) IS ROTATING AROUND THE EAST
LIMB.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE TO HIGH. REGION 9165 IS THE MOST LIKELY CANDIDATE FOR
ENERGETIC FLARE ACTIVITY.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY 15/2100Z TO 16/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE. THE BZ COMPONENT OF THE
IMF HAS FLUCTUATED BETWEEN 0 AND -10NT FOR ABOUT THE LAST 24 HOURS
WHILE WIND SPEED HAS BEEN BELOW 400 KM/S AND DENSITY ABOUT 10 P/CC.
THE GREATER THAN 10 MEV PROTON EVENT DROPPED BELOW EVENT THRESHOLD
(10 PFU) AT 15/2140 UTC. CURRENT FLUX AT GREATER THAN 10 MEV REMAINS
ENHANCED AT ABOUT 5 PFU BUT IS DROPPING SLOWLY.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE MOSTLY UNSETTLED WITH OCCASIONAL ACTIVE PERIODS FOR
THE FIRST TWO DAYS OF THE FORECAST PERIOD. STORM CONDITIONS MAY
BEGIN BY THE THIRD DAY DUE TO THE M5/2B FLARE AND RELATED CME THAT
OCCURRED EARLY ON SEP 16.
III.  EVENT PROBABILITIES 17 SEP-19 SEP
CLASS M    75/75/75
CLASS X    10/10/10
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           16 SEP 175
PREDICTED   17 SEP-19 SEP  180/185/185
90 DAY MEAN        16 SEP 176
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 15 SEP  013/010
ESTIMATED AFR/AP 16 SEP  015/017
PREDICTED AFR/AP 17 SEP-19 SEP  015/015-015/012-040/040
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 17 SEP-19 SEP
A.  MIDDLE LATITUDES
ACTIVE                30/30/50
MINOR STORM           15/15/30
MAJOR-SEVERE STORM    05/05/15
B.  HIGH LATITUDES
ACTIVE                30/30/50
MINOR STORM           15/15/30
MAJOR-SEVERE STORM    05/05/15