:Product: 19980721RSGA.txt
:Issued: 1998 Jul 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 202 ISSUED AT 2200Z ON 21 JUL 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  20/2100Z
TO 21/2100Z:  SOLAR ACTIVITY WAS VERY LOW. THREE NEW REGIONS WERE
NUMBERED TODAY: REGION 8279, (EMERGED ON DISK AT N26E33), REGION
8280 (ROTATING INTO VIEW AT S22E76), AND 8281 (A SIMPLE A-TYPE GROUP
AT N16E73). REGION 8280 APPEARS TO HAVE MATURE PENUMBRA ON LEADER
AND TRAILER PORTIONS OF THE GROUP. REGION 8277 (S12W41) GREW
STEADILY AND EXHIBITED BRIGHT H-ALPHA PLAGE, BUT COULD ONLY MUSTER
ONE SUBFLARE OVER THE PAST 24 HOURS.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
PREDOMINANTLY LOW. THERE IS A CHANCE, HOWEVER, FOR AN ISOLATED
M-CLASS FLARE OVER THE NEXT THREE DAYS. REGIONS 8277 AND 8280 ARE
CONSIDERED TO BE THE MOST LIKELY SOURCE REGIONS FOR ENHANCED
ACTIVITY.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 20/2100Z TO 21/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED AT MID-LATITUDES AND
RANGED FROM QUIET TO MINOR STORM LEVELS AT HIGH LATITUDES. ALTHOUGH
MOST OF THE LAST 24 HOURS WAS QUIET, AN INTERVAL OF ENHANCED
ACTIVITY OCCURRED FROM 0300-1200Z. REAL-TIME SOLAR WIND DATA
INDICATED THAT A SECTOR BOUNDARY CROSSING OCCURRED SHORTLY AFTER
03Z, AND WAS FOLLOWED BY FLUCTUATING INTERPLANETARY MAGNETIC FIELD
CONDITIONS THAT INCLUDED SOME MODERATE NEGATIVE BZ.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE MOSTLY QUIET TO UNSETTLED FOR THE NEXT THREE DAYS.
III.  EVENT PROBABILITIES 22 JUL-24 JUL
CLASS M    20/20/20
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           21 JUL 110
PREDICTED   22 JUL-24 JUL  112/112/115
90 DAY MEAN        21 JUL 107
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 20 JUL  003/006
ESTIMATED AFR/AP 21 JUL  010/009
PREDICTED AFR/AP 22 JUL-24 JUL  010/010-010/008-005/007
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 22 JUL-24 JUL
A.  MIDDLE LATITUDES
ACTIVE                25/25/20
MINOR STORM           10/10/10
MAJOR-SEVERE STORM    05/05/05
B.  HIGH LATITUDES
ACTIVE                25/25/20
MINOR STORM           10/10/10
MAJOR-SEVERE STORM    05/05/05

EFFECTIVE MONDAY, 27 JULY, GOES-9 WILL BE TAKEN OUT OF
OPERATIONAL STATUS, AND GOES-10 WILL BECOME THE PRIMARY
SATELLITE FOR SWO DATA AND PRODUCTS.