:Product: 19990914RSGA.txt
:Issued: 1999 Sep 14 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 257 ISSUED AT 2200Z ON 14 SEP 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  13/2100Z
TO 14/2100Z:  SOLAR ACTIVITY WAS LOW. SEVERAL MINOR, MOSTLY OPTICALLY
UNCORRELATED C-CLASS X-RAY EVENTS OCCURRED THROUGHOUT THE PERIOD.
SMALL GROWTH WAS OBSERVED IN REGIONS 8690 (N15W34) AND 8699
(N21W11). NO SIGNIFICANT CHANGES WERE NOTED IN ANY OF THE REMAINING
FOUR SUNSPOT REGIONS. AN IMPRESSIVE PROMINENCE ERUPTION/CME ON THE
NW LIMB WAS OBSERVED FROM SPACE-BASED IMAGERY AT AROUND 14/0500UT.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO CONTINUE
AT LOW LEVELS. REGIONS 8690, 8692 (S27W14), 8699 (N21W11), AND 8700
(N14E59), ALL HAVE POTENTIAL FOR C-CLASS X-RAY ACTIVITY AND A SMALL
CHANCE FOR AN M-CLASS EVENT.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 13/2100Z TO 14/2100Z:
THE GEOMAGNETIC FIELD RANGED FROM QUIET TO MINOR STORMING. THIS
ONGOING DISTURBANCE, ASSOCIATED WITH A HIGH-SPEED CORONAL HOLE WIND
STREAM, CONTINUES TO PRODUCE PERIODS OF MINOR STORMING DURING LOCAL
NIGHTTIME HOURS,
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD WILL
CONTINUE AT QUIET TO ACTIVE LEVELS DURING LOCAL DAYLIGHT HOURS AND
UNSETTLED TO MINOR STORM DURING LOCAL NIGHTTIME. EFFECTS FROM THE
HIGH-SPEED CORONAL HOLE WIND STREAM WILL BEGIN TO DIMINISH TOMORROW;
HOWEVER, WE MAY EXPERIENCE ACTIVE TO MINOR STORM CONDITIONS ON DAY
TWO FROM CME'S OBSERVED DURING THE PAST TWO DAYS.
III.  EVENT PROBABILITIES 15 SEP-17 SEP
CLASS M    20/20/20
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           14 SEP 156
PREDICTED   15 SEP-17 SEP  160/165/170
90 DAY MEAN        14 SEP 164
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 13 SEP  023/038
ESTIMATED AFR/AP 14 SEP  022/025
PREDICTED AFR/AP 15 SEP-17 SEP  018/015-018/015-010/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 15 SEP-17 SEP
A.  MIDDLE LATITUDES
ACTIVE                50/40/30
MINOR STORM           20/15/10
MAJOR-SEVERE STORM    10/05/05
B.  HIGH LATITUDES
ACTIVE                60/50/40
MINOR STORM           30/25/20
MAJOR-SEVERE STORM    10/10/05