:Product: 20000413RSGA.txt
:Issued: 2000 Apr 13 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 104 ISSUED AT 2200Z ON 13 APR 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  12/2100Z
TO 13/2100Z:  SOLAR ACTIVITY DECREASED TO LOW LEVELS. REGION 8948
(S15W49) SHOWED GRADUAL SIMPLIFICATION OF ITS MAGNETIC STRUCTURE,
BUT MAINTAINED A BETA-GAMMA CLASSIFICATION. IT PRODUCED A C-CLASS
SUBFLARE EARLY IN THE PERIOD. SLIGHT GROWTH WAS REPORTED IN REGION
8959 (S17E14). THE REMAINING REGIONS WERE STABLE INCLUDING NEWLY
NUMBERED REGIONS 8960 (N19W15), 8961 (S25E07), 8962 (N21E76), AND
8963 (N15E74).
IB.  SOLAR ACTIVITY FORECAST:  ACTIVITY IS EXPECTED TO BE AT LOW TO
MODERATE LEVELS. THERE IS A FAIR CHANCE FOR AN ISOLATED M-CLASS
FLARE FROM REGION 8948.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 12/2100Z TO 13/2100Z:
GEOMAGNETIC FIELD ACTIVITY RANGED FROM QUIET TO UNSETTLED LEVELS. THE
GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT REMAINED AT
MODERATE TO HIGH LEVELS.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  GEOMAGNETIC FIELD ACTIVITY IS
EXPECTED TO REMAIN AT QUIET TO UNSETTLED LEVELS DURING MOST OF THE
PERIOD. HOWEVER, BRIEF ACTIVE PERIODS ARE POSSIBLE ON 15 APRIL DUE
TO A SMALL, FAVORABLY POSITIONED CORONAL HOLE. THE GREATER THAN 2
MEV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS EXPECTED TO DECREASE TO
NORMAL TO MODERATE LEVELS EARLY IN THE PERIOD.
III.  EVENT PROBABILITIES 14 APR-16 APR
CLASS M    40/40/40
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           13 APR 164
PREDICTED   14 APR-16 APR  165/165/160
90 DAY MEAN        13 APR 185
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 12 APR  007/005
ESTIMATED AFR/AP 13 APR  005/008
PREDICTED AFR/AP 14 APR-16 APR  008/010-012/012-007/007
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 14 APR-16 APR
A.  MIDDLE LATITUDES
ACTIVE                20/30/15
MINOR STORM           05/10/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                25/35/20
MINOR STORM           10/20/10
MAJOR-SEVERE STORM    01/05/01