000
WTPZ41 KNHC 171438
TCDEP1
TROPICAL STORM MARTY DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP162009
800 AM PDT THU SEP 17 2009
 
THE CLOUD PATTERN HAS BECOME A LITTLE LESS ORGANIZED DURING THE PAST
FEW HOURS AS THE CLOUD TOPS HAVE WARMED SLIGHTLY AND THE OVERALL
SHAPE HAS BECOME ELONGATED.  AN AMSR-E MICROWAVE IMAGE FROM 0913
UTC SUGGESTS THAT THE CENTER WAS LOCATED SLIGHTLY SOUTHWEST OF THE
PREVIOUS ESTIMATES.  THE INITIAL INTENSITY REMAINS 40 KT...WHICH
COULD BE A LITTLE GENEROUS.  MARTY HAS LIKELY REACHED ITS PEAK
INTENSITY.  SOUTHWESTERLY SHEAR IS EXPECTED TO INCREASE DURING THE
NEXT DAY OR TWO AND THE CYCLONE WILL BE MOVING INTO A DRIER AND
MORE STABLE AIRMASS.  THESE NEGATIVE ENVIRONMENTAL FACTORS SHOULD
TRANSLATE INTO A WEAKENING TROPICAL CYCLONE.  THE OFFICIAL FORECAST
IS AT THE LOW END OF THE GUIDANCE AND SHOWS MARTY BECOMING A
REMNANT LOW WITHIN 48 HOURS.
 
MARTY APPEARS TO BE MOVING SLOWLY NORTH-NORTHWESTWARD.  THIS
GENERAL MOTION SHOULD CONTINUE DURING THE NEXT DAY OR TWO.  AS
MARTY WEAKENS AND BECOMES A SHALLOW SYSTEM IT IS EXPECTED TO
TURN WESTWARD IN THE LOW-LEVEL FLOW.  ALL OF THE TRACK
GUIDANCE...EXCEPT THE HWRF...AGREE WITH THIS SOLUTION.  THE HWRF
KEEPS MARTY A DEEP SYSTEM AND MOVES IT INTO THE BAJA PENINSULA.
THIS MODEL IS CONSIDERED AN OUTLIER AT THIS TIME.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      17/1500Z 19.7N 113.1W    40 KT
 12HR VT     18/0000Z 20.3N 113.4W    35 KT
 24HR VT     18/1200Z 21.1N 113.9W    35 KT
 36HR VT     19/0000Z 22.0N 114.8W    30 KT
 48HR VT     19/1200Z 22.8N 115.8W    25 KT...REMNANT LOW
 72HR VT     20/1200Z 23.8N 117.6W    25 KT...REMNANT LOW
 96HR VT     21/1200Z 24.0N 119.0W    20 KT...REMNANT LOW
120HR VT     22/1200Z...DISSIPATED
 
$$
FORECASTER BROWN