Tropical Storm NORMAN

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TROPICAL STORM NORMAN DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP152006
200 PM PDT MON OCT 09 2006
 
RECENT MICROWAVE PASSES FROM BOTH TRMM AND SSMI-S INDICATE THAT THE
CENTER IS SLIGHTLY TO THE WEST THAN PREVIOUSLY THOUGHT.  IN ANY
EVENT...NORMAN HAS CHANGED LITTLE IN ORGANIZATION SINCE THIS
MORNING AND DEEP CONVECTION CONTINUES TO EXIST WITH SLIGHT BANDING
FEATURES.  1800 UTC DVORAK CLASSIFICATIONS WERE 55 KT FROM
TAFB...AND 45 KT FROM BOTH TAFB AND AFWA.  HOWEVER...A 1350 UTC
QUIKSCAT PASS DID NOT REVEAL ANY VECTORS OVER 35 KT AND AS A
RESULT...THE INITIAL INTENSITY WILL BE HELD AT 40 KT.  NORMAN IS
FORECAST TO REMAIN OVER WARM WATERS...BUT IN A GRADUALLY INCREASING
WEST-SOUTHWESTERLY SHEARED ENVIRONMENT FOR THE DURATION OF THE
FORECAST.  THE INTENSITY FORECAST REFLECTS SLIGHT INTENSIFICATION
IN THE NEAR-TERM...FOLLOWED BY WEAKENING TO A REMNANT LOW IN THREE
OR SO DAYS AS THE TROPICAL CYCLONE IS LIKELY TO EVENTUALLY SUCCUMB
TO THE INCREASING SHEAR.  THIS REASONING FOLLOWS CLOSELY WITH THE
SHIPS GUIDANCE.

THE INITIAL MOTION IS 340/6.  NORMAN CONTINUES TO MOVE AROUND THE
WESTERN PERIPHERY OF A WEAK MID-LEVEL RIDGE CENTERED OVER SOUTHERN
MEXICO.  IN ABOUT TWO DAYS...NORMAN IS EXPECTED TO BE NORTH OF
RIDGE AND BECOME EMBEDDED IN STRONG UPPER-LEVEL SOUTHWESTERLY WINDS
AS A MID- TO UPPER-LEVEL LOW DIGS SOUTHWARD FROM CENTRAL
CALIFORNIA.  THERE IS A DICHOTOMY IN THE MODEL TRACK GUIDANCE.  THE
GFDL AND FSU SUPERENSEMBLE FOLLOW THE ABOVE REASONING AND TAKE
NORMAN TO THE NORTH AND THEN TO THE NORTHEAST. ON THE OTHER HAND...
THE UKMET...NOGAPS...AND GFS MODELS ALL TURN THE CYCLONE TO THE
NORTHEAST...EAST...AND EVENTUALLY SOUTH.  THE LATTER SCENARIO
APPEARS UNLIKELY AT THIS TIME...AND THE OFFICIAL FORECAST IS A
BLEND OF THE GFDL...FSU SUPERENSEMBLE...AND IS TO THE LEFT OF THE
PREVIOUS FORECAST. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      09/2100Z 16.2N 117.9W    40 KT
 12HR VT     10/0600Z 16.9N 118.1W    45 KT
 24HR VT     10/1800Z 17.7N 118.0W    45 KT
 36HR VT     11/0600Z 18.6N 117.8W    40 KT
 48HR VT     11/1800Z 19.5N 117.2W    35 KT
 72HR VT     12/1800Z 21.0N 115.5W    25 KT...REMNANT LOW
 96HR VT     13/1800Z 22.5N 113.5W    20 KT...REMNANT LOW
120HR VT     14/1800Z 24.0N 111.5W    20 KT...REMNANT LOW
 
$$
FORECASTER MAINELLI/FRANKLIN
 
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