WTPA42 PHFO 250243
TCDCP2

TROPICAL STORM NEKI DISCUSSION NUMBER  26
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
500 PM HST SAT OCT 24 2009

DEEP CONVECTION HAS REMAINED PERSISTENT NEAR THE CENTER OF NEKI
THROUGHOUT THE DAY. IN FACT...A 24 HOUR LOOP OF GOES IMAGES REVEALS
VERY LITTLE CHANGE IN OVERALL CHARACTER OTHER THAN A SLIGHT
REDUCTION IN UPPER LEVEL OUTFLOW TO THE NORTHEAST. CIMSS DATA FROM
0000 UTC CONTINUES TO SHOW STRONG VERTICAL SHEAR...28 KTS
WORTH...FROM THE WEST-SOUTHWEST. DVORAK INTENSITY ESTIMATES FROM
PHFO...SAB AND JTWC ALL MAINTAIN NEKI AT 50 KT. ASCAT PASSES MISSED
THE SYSTEM ENTIRELY SO THERE WAS NO HELP FROM THAT PLATFORM. WHILE
CIMSS ADT GIVES AN INTENSITY OF 41 KT AT 0000 UTC...THE NOD WILL BE
GIVEN TO THE SUBJECTIVE ESTIMATES BASED ON THE OVERALL SATELLITE
PRESENTATION.  

THERE HAS BEEN NO SIGNIFICANT CHANGE TO THE FORECAST RATIONALE FOR
THIS CYCLE. NEKI IS MOVING IN A WEAK STEERING CURRENT WITH A WEAK
MIDLEVEL RIDGE TO THE SOUTHEAST OVER THE MAIN HAWAIIAN ISLANDS AND
A TROUGH FAR TO THE NORTH. A SIGNIFICANT SHORT WAVE TROUGH IS
EXPECTED TO MOVE IN FROM THE WEST AND ABSORB NEKI. ALL OF THE MAIN
DYNAMICAL MODELS AGREE WITH THIS GENERAL SCENARIO THOUGH DIFFER IN
THE DETAILS. THE FORECAST CLOSELY FOLLOWS THE PREVIOUS FORECAST
WITH SLIGHT ADJUSTMENTS IN SPEED AND IS ON THE EAST SIDE OF THE
DYNAMICAL GUIDANCE ENVELOPE. IN ANY CASE...NEKI IS EXPECTED TO BE A
NON-ENTITY AS A TROPICAL SYSTEM BY TUESDAY EVENING.
 
NEKI IS MOVING OVER MARGINAL AND DECREASING SEA SURFACE
TEMPERATURES. THIS ALONG WITH SIGNIFICANT LEVELS OF VERTICAL SHEAR
SUPPORTS A WEAKENING TREND AS INDICATED BY THE MAIN INTENSITY
OBJECTIVE AIDS. THUS...FORECAST CALLS FOR NEKI TO WEAKEN SLOWLY
OVER THE NEXT COUPLE OF DAYS...FOLLOWED BY A TRANSITION TO AN
EXTRATROPICAL STATE ON TUESDAY.
 
THE LATEST BUOY DATA INDICATE IMPROVING WIND AND SEA CONDITIONS. 
THEREFORE...THE TROPICAL STORM WARNING FOR THE PAPAHANAUMOKUAKEA
NATIONAL MONUMENT WILL BE DISCONTINUED AS OF 500 PM HST.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      25/0300Z 25.3N 163.8W    50 KT
 12HR VT     25/1200Z 26.0N 163.7W    45 KT
 24HR VT     26/0000Z 27.2N 163.7W    45 KT
 36HR VT     26/1200Z 28.9N 163.7W    40 KT
 48HR VT     27/0000Z 31.7N 163.0W    40 KT...BECOMING EXTRATROPICAL
 72HR VT     28/0000Z 43.0N 156.5W    30 KT...EXTRATROPICAL
 
$$
FORECASTER KODAMA