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Tropical Storm KRISTY (Text)

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TROPICAL STORM KRISTY DISCUSSION NUMBER  29
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP122006
800 PM PDT TUE SEP 05 2006

EASTERLY SHEAR ABATED SOMEWHAT OVER KRISTY AND IT APPEARED THAT THE
CENTER HAD BECOME MORE EMBEDDED WITHIN THE DEEP CONVECTION. 
HOWEVER RECENT IMAGES SUGGEST THAT THE CENTER IS CLOSE TO NORTHERN 
EDGE OF THE DENSE OVERCAST.  THE EXTENT AND DEPTH OF THE CONVECTION
HAS DIMINISHED...AND THE LATEST DVORAK INTENSITY ESTIMATES FROM THE
VARIOUS AGENCIES RANGE FROM 30 TO 35 KT.  THE CURRENT INTENSITY
ESTIMATE IS ADJUSTED DOWNWARD SLIGHTLY TO 35 KT.  THIS IS PROBABLY
JUST ANOTHER ONE OF KRISTY'S INTENSITY FLUCTUATIONS...AND SOME
RE-STRENGTHENING IS INDICATED IN AN AN ENVIRONMENT OF WEAK SHEAR AND
MARGINAL SST FOR THE NEXT COUPLE OF DAYS.  THE OFFICIAL WIND SPEED
FORECAST IS NEAR OR SLIGHTLY BELOW THE SHIPS GUIDANCE.  LATE IN THE
PERIOD...THE ENVIRONMENT MAY BECOME MORE HOSTILE DUE TO AN
UPPER-LEVEL TROUGH THAT IS FORECAST TO BE JUST TO THE NORTHWEST OF
KRISTY AROUND 120 HOURS...AND THE TROPICAL CYCLONE COULD WEAKEN
MORE THAN INDICATED HERE.

MY INITIAL MOTION ESTIMATE IS 285/11...WHICH IS VERY CLOSE TO THE
CLIMATOLOGICAL MEAN FOR AN EASTERN NORTH PACIFIC BASIN TROPICAL
CYCLONE.  A MID-TROPOSPHERIC RIDGE TO THE NORTH OF KRISTY IS
PREDICTED TO WEAKEN AS THE CENTER OF THE HIGH PRESSURE AREA SHIFTS
WESTWARD OVER THE NEXT FEW DAYS.  THE OFFICIAL TRACK FORECAST IS
JUST SLIGHTLY TO THE NORTH OF THAT FROM THE PREVIOUS PACKAGE BUT
SOUTH OF MOST OF THE GUIDANCE.  THE GFS MOVES KRISTY SIGNIFICANTLY
FASTER THAN ANY OF THE OTHER DYNAMICAL MODELS...AND IS PROBABLY
BASED ON NEAR-SURFACE STEERING WINDS FOR A VERY WEAK SYSTEM.  WHILE
THIS MAY TURN OUT TO BE THE CORRECT SOLUTION...IT IS PREFERABLE TO
MAINTAIN MORE CONTINUITY WITH THE PREVIOUS FORECAST AND TO BE
CLOSER TO THE MODEL CONSENSUS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      06/0300Z 17.1N 123.9W    35 KT
 12HR VT     06/1200Z 17.4N 125.5W    40 KT
 24HR VT     07/0000Z 17.8N 127.5W    45 KT
 36HR VT     07/1200Z 18.0N 129.3W    45 KT
 48HR VT     08/0000Z 18.0N 130.7W    45 KT
 72HR VT     09/0000Z 18.0N 133.5W    45 KT
 96HR VT     10/0000Z 18.5N 136.5W    40 KT
120HR VT     11/0000Z 19.0N 139.5W    35 KT
 
$$
FORECASTER PASCH
 
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