000
WTNT41 KNHC 291456
TCDAT1
TROPICAL STORM NOEL DISCUSSION NUMBER   8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL162007
1100 AM EDT MON OCT 29 2007
 
NOEL HAS BECOME LESS ORGANIZED AS IT INTERACTS WITH THE COMPLEX
TERRAIN OF HISPANIOLA.  A MID-LEVEL VORTICITY MAXIMUM EMERGED NORTH
OF THE ISLAND A FEW HOURS AGO...AND VISIBLE IMAGERY SUGGESTS A
LOW-LEVEL CENTER IS REFORMING ALONG THE NORTHWESTERN COAST OF
HAITI.  UNTIL THE NEXT AIR FORCE RECONNAISSANCE PLANE INVESTIGATES
THE AREA THIS AFTERNOON...THE LOCATION...FORWARD MOTION...AND EVEN
THE EXISTENCE OF A LOW-LEVEL CENTER REMAIN RATHER UNCERTAIN.

OUR BEST ESTIMATE OF THE INITIAL MOTION IS NORTH-NORTHWESTWARD OR
335/10...WITH STEERING PROVIDED BY A LOW- TO MID-LEVEL RIDGE NORTH
AND EAST OF THE CYCLONE.  NEARLY ALL OF THE DYNAMICAL MODELS
FORECAST A SURFACE LOW TO BECOME RE-ESTABLISHED SOMEWHERE OVER THE
BAHAMAS DURING THE NEXT DAY OR SO...BUT THEY DO NOT AGREE ON THE
VERTICAL EXTENT OF THE CIRCULATION. THE GFDL CONTINUES TO INSIST ON
NOEL BECOMING A HURRICANE THAT WILL ACCELERATE QUICKLY NORTHWARD
AND THEN NORTHEASTWARD. THE OTHER EXTREME IS THE ECMWF THAT DEPICTS
A WEAK SURFACE LOW HANGING OUT NEAR CUBA FOR THE NEXT FIVE DAYS.
THE REMAINING MODELS ARE IN BETWEEN...AND FORECAST A GENERAL
NORTHWESTWARD MOTION WITH A DECREASE IN FORWARD SPEED DURING THE
NEXT 48 HOURS. SOME OF THOSE MODELS...INCLUDING THE GFS...FORECAST
LITTLE MOTION ON DAYS 3-5...WHILE THE NOGAPS SHOWS A NORTHEASTWARD
ACCELERATION IN THAT TIME FRAME.  THE NEW OFFICIAL TRACK FORECAST
SHOWS A WEAKENING AND INCREASINGLY SHALLOW CYCLONE THAT SLOWLY
RECURVES NORTHEASTWARD OVER THE BAHAMAS AFTER 48 HOURS...IN
RESPONSE TO AN APPROACHING SHORT-WAVE TROUGH...SIMILAR TO THE HWRF
SOLUTION AND A LITTLE SLOWER THAN THE PREVIOUS ADVISORY.

ASSUMING THE CYCLONE REGAINS SUFFICIENT ORGANIZATION AFTER BEING
DISRUPTED OVER HISPANIOLA...ATMOSPHERIC AND OCEAN CONDITIONS SHOULD
PROVIDE NOEL WITH AN OPPORTUNITY TO STRENGTHEN A LITTLE DURING THE
NEXT DAY OR TWO.  THEREAFTER...WESTERLY WIND SHEAR SHOULD
DRAMATICALLY INCREASE AND INDUCE A WEAKENING TREND.  THE NEW
OFFICIAL INTENSITY FORECAST IS ADJUSTED SLIGHTLY DOWNWARD COMPARED
TO THE PREVIOUS ADVISORY...ESPECIALLY AFTER 48 HOURS.  THIS
FORECAST IS IN BEST AGREEMENT WITH THE LGEM AND HWRF GUIDANCE...AND
BELOW THE SHIPS AND GFDL.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/1500Z 19.9N  73.0W    40 KT
 12HR VT     30/0000Z 21.2N  73.7W    40 KT
 24HR VT     30/1200Z 22.4N  74.4W    45 KT
 36HR VT     31/0000Z 23.4N  75.4W    50 KT
 48HR VT     31/1200Z 24.3N  76.7W    50 KT
 72HR VT     01/1200Z 26.0N  76.5W    45 KT
 96HR VT     02/1200Z 28.0N  75.0W    40 KT
120HR VT     03/1200Z 30.0N  72.5W    35 KT
 
$$
FORECASTER KNABB/MAINELLI