:Product: 19990416RSGA.txt
:Issued: 1999 Apr 16 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 106 ISSUED AT 2200Z ON 16 APR 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  15/2100Z
TO 16/2100Z:  SOLAR ACTIVITY WAS VERY LOW. A NEW REGION WAS NUMBERED
TODAY AS REGION 8517 (N20W21).
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE VERY
LOW TO LOW THROUGH THE FORECAST PERIOD.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 15/2100Z TO 16/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE. AT 16/1036Z A SHOCK
ARRIVED AT L1. A SUDDEN IMPULSE OCCURRED AT 16/1126Z. THE SOLAR WIND
DENSITY OFF OF THE ACE SPACECRAFT INCREASED TO 68 P/CC AT 16/1443Z.
SEVERAL MAGNETOPAUSE CROSSINGS WERE OBSERVED ON THE GOES-8 (W74)
BETWEEN 16/1515-1820Z. THIS ACTIVITY CORRELATES WELL WITH THE
CORONAL MASS EJECTION OBSERVED ON 13 APRIL.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE THE FIRST DAY OF THE FORECAST
WITH PERIODS OF MINOR STORM CONDITIONS POSSIBLE. THIS ACTIVITY IS
ANTICIPATED DUE TO THE CME OBSERVED ON 13 APRIL. THE REMAINDER OF
THE PERIOD IS EXPECTED TO BE QUIET TO UNSETTLED.
III.  EVENT PROBABILITIES 17 APR-19 APR
CLASS M    15/15/15
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           16 APR 123
PREDICTED   17 APR-19 APR  120/118/116
90 DAY MEAN        16 APR 135
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 15 APR  002/004
ESTIMATED AFR/AP 16 APR  010/015
PREDICTED AFR/AP 17 APR-19 APR  020/020-010/010-005/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 17 APR-19 APR
A.  MIDDLE LATITUDES
ACTIVE                30/20/15
MINOR STORM           20/10/05
MAJOR-SEVERE STORM    10/05/01
B.  HIGH LATITUDES
ACTIVE                35/25/20
MINOR STORM           25/15/10
MAJOR-SEVERE STORM    15/10/05