029
WTPZ45 KNHC 170831
TCDEP5
TROPICAL STORM KIKO DISCUSSION NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP152007
200 AM PDT WED OCT 17 2007
ALTHOUGH THE LOW-LEVEL CENTER IS NOT EASY TO FIND...IT APPEARS TO BE
LOCATED BACK UNDER THE DEEP CONVECTION. A QUIKSCAT PASS FROM 0136
UTC SHOWED SOME 30 KT WINDS OUTSIDE OF THE HEAVY SHOWERS...SO IT IS
REASONABLE TO ASSUME THAT TROPICAL STORM FORCE WINDS ARE OCCURRING
IN AREAS OF STRONG CONVECTION. THEREFORE KIKO IS BEING UPGRADED
BACK TO A 35-KT TROPICAL STORM AT THIS TIME. THE TROPICAL STORM
FORCE WINDS APPEAR TO BE CONFINED TO THE SOUTHWEST QUADRANT OF THE
CYCLONE AT THIS TIME.
A RECENT AMSU-B OVERPASS AND AN EARLIER SSM/I PASS INDICATE THAT THE
CENTER HAS EDGED A LITTLE FARTHER TO THE EAST OR EAST-NORTHEAST AND
THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 070/2. THE STEERING
CURRENT REMAINS ILL-DEFINED. KIKO IS EMBEDDED WITHIN A LOW-LEVEL
CYCLONIC CIRCULATION AND APPEARS TO BE EXECUTING A COUNTERCLOCKWISE
LOOP AT THIS TIME. IT IS DIFFICULT TO ASCERTAIN A WELL-DEFINED
STEERING MECHANISM IN THE GLOBAL MODEL FORECAST FIELDS FOR THE NEXT
SEVERAL DAYS. A MID-LEVEL RIDGE BUILDS VERY WEAKLY TO THE NORTH OF
THE TROPICAL CYCLONE OVER THE NEXT COUPLE OF DAYS BUT IS PREDICTED
TO WEAKEN THEREAFTER. TRACK GUIDANCE MODELS HAVE GENERALLY SHIFTED
TO THE EAST ON THIS CYCLE. ACCORDINGLY THE OFFICIAL TRACK FORECAST
IS ADJUSTED A LITTLE TO THE EAST OF THE PREVIOUS ONE...ALBEIT NOT
AS FAR EAST AND NORTH AS THE GUNA CONSENSUS AT DAYS 3 THROUGH 5.
THE SHAPE OF THE CONVECTIVE CLOUD PATTERN AND HIGH-CLOUD MOTIONS
INDICATE THAT STRONG EASTERLY SHEAR CONTINUES TO IMPACT KIKO. THE
SHIPS MODEL...USING THE GFS WIND FORECAST...SHOWS A RELAXATION OF
THE SHEAR IN ABOUT 36 HOURS. THIS WOULD ALLOW FOR SOME
STRENGTHENING. THE OFFICIAL INTENSITY FORECAST IS RATHER CLOSE
TO THE SHIPS PREDICTION AND ALSO NOT FAR FROM THE GFDI FORECAST
EXCEPT NEAR THE END OF THE PERIOD...WHEN THE LATTER MODEL SHOWS
MORE STRENGTHENING.
THE 12-FT SEAS RADII OVER THE SOUTHERN SEMICIRCLE WERE ESTIMATED
FROM AN OBSERVATION FROM A NOAA SHIP WITH CALL SIGN WTEJ.
FORECAST POSITIONS AND MAX WINDS
INITIAL 17/0900Z 14.2N 107.3W 35 KT
12HR VT 17/1800Z 14.4N 107.0W 35 KT
24HR VT 18/0600Z 14.8N 106.8W 35 KT
36HR VT 18/1800Z 15.2N 106.8W 40 KT
48HR VT 19/0600Z 15.7N 106.8W 40 KT
72HR VT 20/0600Z 16.7N 106.8W 45 KT
96HR VT 21/0600Z 17.5N 107.5W 50 KT
120HR VT 22/0600Z 18.0N 108.0W 50 KT
FORECASTER PASCH
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