Hurricane MARIE

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HURRICANE MARIE DISCUSSION NUMBER  13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP142008
200 AM PDT SAT OCT 04 2008
 
MARIE CONTINUES TO SHOW A POORLY-DEFINED EYE IN INFRARED SATELLITE
IMAGERY THIS MORNING.  SEVERAL RECENT MICROWAVE OVERPASSES ALSO
SHOW THE EYE...WITH INDICATIONS THAT THE SURROUNDING EYEWALL IS
ERODING ON THE SOUTH SIDE.  SATELLITE INTENSITY ESTIMATES HAVE
INCREASED TO 77 KT FROM TAFB...AND REMAIN 65 KT FROM SAB.  BASED ON
THIS...THE INITIAL INTENSITY IS INCREASED TO 70 KT.  ANALYSES FROM
CIMSS AT THE UNIVERSITY OF WISCONSIN SHOW THAT MARIE IS NOW
EXPERIENCING ABOUT 10 KT OF SOUTHWESTERLY VERTICAL WIND SHEAR...
WITH GOOD CIRRUS OUTFLOW IN THE NORTHEASTERN SEMICIRCLE AND POOR
ELSEWHERE.

THE INITIAL MOTION IS NOW 005/3.  MARIE IS CURRENTLY LOCATED IN A
BREAK IN THE SUBTROPICAL RIDGE TO THE EAST OF AN ANTICYCLONE
CENTERED TO THE EAST OF THE HAWAIIAN ISLANDS...AND TO THE SOUTH OF
A STRONG DEEP-LAYER TROUGH ALONG THE U. S. WEST COAST.  SATELLITE
IMAGERY SUGGESTS A SMALL DEEP-LAYER RIDGE HAS FORMED BETWEEN MARIE
AND TROPICAL DEPRESSION FIFTEEN-E...AND THIS FEATURE MAY BE THE
CAUSE OF THE CURRENT NORTHWARD MOTION.  THE LARGE-SCALE MODELS
FORECAST MID/UPPER-LEVEL RIDGING TO BUILD NORTH OF MARIE IN 18-36
HR...WHICH SHOULD ALLOW THE CYCLONE TO RESUME A WESTWARD MOTION. 
UNTIL THEN...A SLOW NORTHWARD DRIFT IS EXPECTED.  THE FORECAST
TRACK NOW CALLS FOR A NORTHWARD MOTION FOR 12 HR OR SO...FOLLOWED
BY A GRADUAL TURN TOWARD THE WEST.  THIS PART OF THE FORECAST TRACK
IS IN THE CENTER OF THE GUIDANCE ENVELOPE.  AFTER 72 HR...THE
LARGE-SCALE MODELS FORECAST PART OF THE DEEP-LAYER TROUGH TO SPLIT
OFF AND MOVE SOUTHWARD WEST OF BAJA CALIFORNIA.  THE GFDL...WHICH
HAS MARIE MOVING MORE SLOWLY WESTWARD UNDER THE RIDGE...TURNS THE
CYCLONE SOUTHWESTWARD IN RESPONSE TO THE TROUGH.  THE NOGAPS AND
HWRF...WHICH HAVE A FASTER WESTWARD MOTION...SHOW THE TROUGH HAVING
LITTLE IMPACT ON MARIE'S TRACK.  SINCE THE FORECAST TRACK HAS MARIE
MOVING WESTWARD AT A SPEED BETWEEN THAT OF THE ABOVE-MENTIONED
MODELS...IT WILL SHOW A SMALL SOUTHWARD NUDGE AFTER 96 HR.  THE
TRACK AFTER 72 HR IS A LITTLE NORTH OF THE MODEL CONSENSUS.
 
THE LARGE-SCALE MODELS CONTINUE TO FORECAST A LIGHT-SHEAR
ENVIRONMENT NEAR MARIE THROUGH THE FORECAST PERIOD.  HOWEVER...THE
NORTHWARD MOTION IS TAKING THE CENTER NORTH OF THE 26C SEA SURFACE
TEMPERATURE ISOTHERM...AND THE NORTHWARD SHIFT IN THE FORECAST
TRACK SUGGESTS MARIE WILL ENCOUNTER COLDER WATER THAN PREVIOUSLY
EXPECTED.  ALL INTENSITY GUIDANCE FORECASTS A GRADUAL WEAKENING...
AND THE INTENSITY FORECAST FOLLOWS THIS SCENARIO.  THE INTENSITY
FORECAST HAS MARIE WEAKENING TO A TROPICAL STORM IN 24-36 HR...A
TROPICAL DEPRESSION IN ABOUT 96 HR...AND A REMNANT LOW IN ABOUT 120
HR.  IT SHOULD BE NOTED THAT THE FORECAST WESTWARD MOTION IS
ROUGHLY PARALLEL TO THE SST ISOTHERMS...SO SMALL DEVIATIONS TO THE
NORTH OR SOUTH OF THE TRACK COULD MAKE A SIGNIFICANT DIFFERENCE IN
THE SSTS THAT MARIE ENCOUNTERS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/0900Z 18.4N 122.0W    70 KT
 12HR VT     04/1800Z 18.6N 122.0W    70 KT
 24HR VT     05/0600Z 19.0N 122.4W    65 KT
 36HR VT     05/1800Z 19.3N 123.3W    55 KT
 48HR VT     06/0600Z 19.4N 124.4W    45 KT
 72HR VT     07/0600Z 19.5N 127.5W    35 KT
 96HR VT     08/0600Z 19.5N 130.5W    30 KT
120HR VT     09/0600Z 19.0N 133.0W    25 KT...REMNANT LOW
 
$$
FORECASTER BEVEN
 
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