:Product: 19991018RSGA.txt
:Issued: 1999 Oct 18 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 291 ISSUED AT 2200Z ON 18 OCT 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  17/2100Z
TO 18/2100Z:  SOLAR ACTIVITY CONTINUED AT LOW LEVELS. REGION 8731
(N13W33) SHOWED A SMALL INCREASE IN SPOT COUNT AND REMAINED A LARGE,
MAGNETICALLY COMPLEX REGION. IT PRODUCED ISOLATED C-CLASS SUBFLARES
DURING THE PERIOD. NO SIGNIFICANT CHANGES WERE OBSERVED IN THE
REMAINING REGIONS AND NO NEW REGIONS WERE ASSIGNED.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE AT
LOW TO MODERATE LEVELS. REGION 8731, THOUGH RELATIVELY INACTIVE
DURING THE PAST FEW DAYS, STILL APPEARS CAPABLE OF M-CLASS FLARE
PRODUCTION. THERE IS A SLIGHT CHANCE FOR A MAJOR FLARE FROM THIS
REGION AS WELL.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 17/2100Z TO 18/2100Z:
GEOMAGNETIC FIELD ACTIVITY WAS AT QUIET TO UNSETTLED LEVELS. THE
GREATER THAN 2 MEV ELECTRON FLUX REMAINED AT MODERATE TO HIGH
LEVELS.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  GEOMAGNETIC FIELD ACTIVITY IS
EXPECTED TO REMAIN AT QUIET TO UNSETTLED LEVELS DURING THE FIRST TWO
DAYS OF THE PERIOD. ACTIVITY IS EXPECTED TO INCREASE TO UNSETTLED TO
ACTIVE LEVELS ON THE FINAL DAY DUE TO CORONAL HOLE EFFECTS. THE
GREATER THAN 2 MEV ELECTRON FLUX IS EXPECTED TO REMAIN AT MODERATE
TO HIGH LEVELS.
III.  EVENT PROBABILITIES 19 OCT-21 OCT
CLASS M    50/50/50
CLASS X    10/10/10
PROTON     10/10/10
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           18 OCT 173
PREDICTED   19 OCT-21 OCT  170/170/165
90 DAY MEAN        18 OCT 158
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 17 OCT  016/026
ESTIMATED AFR/AP 18 OCT  008/012
PREDICTED AFR/AP 19 OCT-21 OCT  008/010-010/008-015/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 19 OCT-21 OCT
A.  MIDDLE LATITUDES
ACTIVE                10/20/30
MINOR STORM           05/10/15
MAJOR-SEVERE STORM    01/01/05
B.  HIGH LATITUDES
ACTIVE                15/25/40
MINOR STORM           05/15/20
MAJOR-SEVERE STORM    01/01/10