:Product: 19990922RSGA.txt
:Issued: 1999 Sep 22 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 265 ISSUED AT 2200Z ON 22 SEP 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  21/2100Z
TO 22/2100Z:  SOLAR ACTIVITY WAS LOW. A C5/1F FLARE FROM REGION 8706
(N19E38) AT 1340Z WAS THE LARGEST EVENT OF THE DAY. NEWLY ASSIGNED
REGION 8708 (S09E55) PRODUCED FREQUENT SUBFLARES DURING THE FIRST
HALF OF THE INTERVAL. ANOTHER NEW REGION, 8707 (S07W08) HAS BEEN
QUIET.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 21/2100Z TO 22/2100Z:
THE GEOMAGNETIC FIELD WAS AT QUIET TO MINOR STORM LEVELS. A SMALL
SUDDEN IMPULSE, MEASURED AT BOULDER TO BE  8 NANOTESLA, OCCURRED AT
1222Z. SATELLITE DATA FROM ACE SHOWED THE PASSAGE OF AN
INTERPLANETARY SHOCK JUST PRIOR. SOLAR WIND SPEEDS NEAR 600 KM/S,
AND BZ MEASURING NEAR -15 NT ARE NOW  OCCURRING. THE SOLAR ORIGIN OF
THIS EJECTION IS NOT WELL-ESTABLISHED.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT ACTIVE TO MINOR STORM LEVELS FOR THE NEXT 24 HOURS.
SOLAR WIND DATA INDICATE HIGH SPEEDS AND RELATIVELY STRONG SOUTHWARD
MAGNETIC FIELDS. UNSETTLED TO ACTIVE CONDITIONS SHOULD PREVAIL THE
LAST TWO DAYS.
III.  EVENT PROBABILITIES 23 SEP-25 SEP
CLASS M    15/15/15
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           22 SEP 140
PREDICTED   23 SEP-25 SEP  140/135/135
90 DAY MEAN        22 SEP 163
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 21 SEP  010/010
ESTIMATED AFR/AP 22 SEP  020/025
PREDICTED AFR/AP 23 SEP-25 SEP  020/025-015/015-015/012
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 23 SEP-25 SEP
A.  MIDDLE LATITUDES
ACTIVE                50/40/40
MINOR STORM           20/10/10
MAJOR-SEVERE STORM    05/01/01
B.  HIGH LATITUDES
ACTIVE                60/50/50
MINOR STORM           20/10/10
MAJOR-SEVERE STORM    05/01/01