:Product: 19981021RSGA.txt
:Issued: 1998 Oct 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 294 ISSUED AT 2200Z ON 21 OCT 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  20/2100Z
TO 21/2100Z:  SOLAR ACTIVITY WAS LOW. THE LARGEST X-RAY FLARE OF THE
PAST DAY WAS A LONG DURATION C7 THAT, FROM EIT IMAGES, APPARENTLY
OCCURRED FROM BEHIND THE SOUTHWEST LIMB. THIS FLARE WAS ASSOCIATED
WITH A WEAK TYPE II/IV RADIO SWEEP AND CORONAL LOOPS. REGION 8365
(S28W24) HAS BEEN EMERGING RAPIDLY, MORE THAN DOUBLING ITS SUNSPOT
AREA. THIS REGION HAS STARTED TO GENERATE SMALL FLARES; THE LARGEST
SO FAR BEING A C1/SF AT 21/1132Z. NEW REGION 8367 (N16E00) EMERGED
JUST TO THE SOUTHEAST OF REGION 8362 (N18W08).
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.
C-CLASS ACTIVITY IS POSSIBLE FROM REGION 8361 (N15W94), AS IT ROUNDS
THE WEST LIMB, AND REGION 8365.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 20/2100Z TO 21/2100Z:
THE GEOMAGNETIC FIELD WAS UNSETTLED TO ACTIVE. THIS ACTIVITY IS
BELIEVED TO BE THE RESULT OF ALFVENIC WAVE ACTIVITY ASSOCIATED WITH
A HIGH-SPEED STREAM FROM THE NORTHERN POLAR CORONAL HOLE. THE 2 MEV
ELECTRON FLUX WAS MODERATE TO HIGH.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE FOR THE NEXT 24 HOURS, BECOMING
QUIET TO UNSETTLED.
III.  EVENT PROBABILITIES 22 OCT-24 OCT
CLASS M    10/05/01
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           21 OCT 118
PREDICTED   22 OCT-24 OCT  115/115/115
90 DAY MEAN        21 OCT 132
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 20 OCT  011/017
ESTIMATED AFR/AP 21 OCT  022/020
PREDICTED AFR/AP 22 OCT-24 OCT  018/020-015/012-010/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 22 OCT-24 OCT
A.  MIDDLE LATITUDES
ACTIVE                15/15/15
MINOR STORM           10/10/05
MAJOR-SEVERE STORM    05/01/01
B.  HIGH LATITUDES
ACTIVE                15/15/15
MINOR STORM           10/10/05
MAJOR-SEVERE STORM    05/01/01