000
WTPZ41 KNHC 170835
TCDEP1
TROPICAL STORM MARTY DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP162009
200 AM PDT THU SEP 17 2009
 
THE CLOUD PATTERN HAS NOT CHANGED VERY MUCH DURING THE PAST FEW
HOURS...PERHAPS IT IS A LITTLE BIT LESS ORGANIZED. MICROWAVE
IMAGERY SHOWS THAT THE CENTER IS STILL NEAR THE NORTHERN EDGE OF
THE CONVECTION. QUIKSCAT AND ASCAT DATA FROM A FEW HOURS AGO...WHEN
THE CLOUD PATTERN WAS A LITTLE BETTER DEFINED...SHOWED A FEW RAIN
CONTAMINATED VECTORS OF 35 TO 40 KNOTS AND 30 KNOTS...RESPECTIVELY. 
THE INITIAL INTENSITY IS KEPT AT 40 KNOTS. MARTY COULD STRENGTHEN A
LITTLE TODAY WHILE THE SHEAR IS LIGHT...BUT UNANIMOUSLY...ALL
GLOBAL MODELS SHOW A BAND OF UNFAVORABLE STRONG UPPER-LEVEL
WESTERLY WINDS OVER MARTY AS SOON AS 24 HOURS. THE FORECAST CALLS
FOR A GRADUAL WEAKENING AND MARTY SHOULD BECOME A REMNANT LOW BY 72
HOURS OR EARLIER.           

MARTY APPEARS TO BE MOVING TOWARD THE NORTH-NORTHWEST AT 4 KNOTS
ALONG A WEAKNESS IN THE SUBTROPICAL RIDGE. THIS GENERAL MOTION
SHOULD CONTINUE DURING THE NEXT 24 HOUR OR SO. A GRADUAL TURN TO
THE WEST-NORTHWEST AND WEST SHOULD BEGIN AS MARTY WEAKENS AND
BECOME A SHALLOW SYSTEM STEERED BY THE LOW LEVEL FLOW. WITH THE
EXCEPTION OF THE HWRF WHICH BRINGS MARTY NORTHWARD OVER BAJA
CALIFORNIA...THE REMAINDER OF THE GUIDANCE TURNS MARTY TOWARD THE
WEST AND SO DOES THE OFFICIAL FORECAST. THE HWRF SOLUTION IS NOT
CONSISTENT WITH THE TRACK OF A WEAKENING CYCLONE STEERED BY THE
LOW-LEVEL FLOW.      
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      17/0900Z 19.7N 112.9W    40 KT
 12HR VT     17/1800Z 20.2N 113.1W    45 KT
 24HR VT     18/0600Z 21.0N 113.5W    45 KT
 36HR VT     18/1800Z 22.0N 114.5W    40 KT
 48HR VT     19/0600Z 23.0N 115.5W    30 KT
 72HR VT     20/0600Z 24.0N 117.0W    25 KT...REMNANT LOW
 96HR VT     21/0600Z 24.5N 118.5W    20 KT...REMNANT LOW
120HR VT     22/0600Z 24.5N 120.5W    20 KT...REMNANT LOW
 
$$
FORECASTER AVILA