:Product: 19990408RSGA.txt
:Issued: 1999 Apr 08 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 098 ISSUED AT 2200Z ON 08 APR 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  07/2100Z
TO 08/2100Z:  SOLAR ACTIVITY WAS MODERATE. REGION 8508 (N22E13)
PRODUCED AN IMPULSIVE M1/SF AT 08/1613Z. THIS EVENT WAS PRECEDED BY
MANY PLAGE FLUCTUATIONS AND SEVERAL SMALL TO MID C-CLASS FLARES FROM
THIS REGION.  DURING THE LAST 24 HOURS, REGION 8508 MAINTAINED ITS
MIXED POLARITIES AND GREW AT A MODERATE PACE. A SMALL REGION EMERGED
NEAR S27E53 AND WAS NUMBERED AS REGION 8512.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD BE LOW TO
MODERATE FOR THE NEXT THREE DAYS. REGION 8508 MAY BE ENTERING A
PHASE OF RE-GROWTH AND THE FREQUENCY OF M-CLASS EVENTS MAY INCREASE.
X-CLASS FLARES ARE NOT EXPECTED AT THIS TIME BUT CONTINUED GROWTH IN
REGION 8508 WOULD CHANGE THAT FORECAST.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 07/2100Z TO 08/2100Z:
THE GEOMAGNETIC FIELD BEGAN THE PERIOD AT QUIET LEVELS. ACTIVE
CONDITIONS WERE OBSERVED DURING THE 08/1500-1800Z PERIOD. UNSETTLED
CONDITIONS OCCURRED AT THE END OF THE PERIOD.  NO SHOCK WAS OBSERVED
IN THE NEARLY CONTINUOUS SOLAR WIND RECORD AND VELOCITY WAS
RELATIVELY LOW BETWEEN 350-400 KM/S.  ENERGETIC ELECTRON FLUXES AT
GEOSYNCHRONOUS ORBIT REACHED HIGH LEVELS DURING THE PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD BE
PREDOMINANTLY QUIET TO UNSETTLED FOR THE NEXT THREE DAYS. ISOLATED
ACTIVE INTERVALS ARE POSSIBLE ON 09 APR.
III.  EVENT PROBABILITIES 09 APR-11 APR
CLASS M    50/50/50
CLASS X    10/10/10
PROTON     10/10/10
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           08 APR 139
PREDICTED   09 APR-11 APR  140/139/135
90 DAY MEAN        08 APR 134
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 07 APR  010/009
ESTIMATED AFR/AP 08 APR  010/012
PREDICTED AFR/AP 09 APR-11 APR  010/010-010/010-008/008
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 09 APR-11 APR
A.  MIDDLE LATITUDES
ACTIVE                25/15/15
MINOR STORM           15/05/05
MAJOR-SEVERE STORM    05/01/05
B.  HIGH LATITUDES
ACTIVE                25/15/15
MINOR STORM           15/05/05
MAJOR-SEVERE STORM    05/01/05