WTPA42 PHFO 222046
TCDCP2

HURRICANE NEKI DISCUSSION NUMBER  17
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
1100 AM HST THU OCT 22 2009

HURRICANE NEKI IS SLOWLY WEAKENING AS STRONG SOUTHWESTERLY SHEAR
CONTINUES TO IMPACT THE SYSTEM. FIXES FROM CPHC...JTWC...AND SAB
ALL CAME IN WITH CI VALUES OF 5.0 WHICH SETS THE INITIAL INTENSITY
AT 90 KT. 

THE INITIAL POSITION HAS BEEN SHIFTED TO THE LEFT WITH THE SYSTEM
MOVING A BIT SLOWER THAN THE PREVIOUS FORECAST. THIS WAS MAINLY DUE
TO A RECENT SSMIS PASS AND EARLY MORNING VISIBLE IMAGERY. MODELS
ARE IN GOOD AGREEMENT WITH A CONTINUED NORTH-NORTHEAST MOTION IN
THE SHORT TERM THEN A TURN MORE TO THE NORTHEAST WITH GRADUAL
ACCELERATION EXPECTED AS THE SYSTEM INTERACTS WITH AN ENCROACHING
FRONT AND ITS ASSOCIATED UPPER LEVEL TROUGH. THE LATEST FORECAST
TRACK IS PRETTY MUCH DOWN THE MIDDLE OF THE GUIDANCE BUT SLIGHTLY
TO THE LEFT OF THE PREVIOUS FORECAST MAINLY DUE TO THE WESTWARD
SHIFT OF THE INITIAL POSITION.

NEKI WILL REMAIN OVER 26 C OR WARMER WATER THROUGH 48 HOURS...THEN
MOVE ACROSS COOLER WATERS THROUGH THE REST OF ITS FORECAST TRACK.
THE LATEST UW-CIMSS VERTICAL WIND SHEAR PRODUCT SHOWS SOUTHWEST
SHEAR OF 24 KT. THIS STRONG SHEAR IS EXPECTED TO CONTINUE FOR THE
NEXT SEVERAL DAYS AND WILL BE THE PRIMARY KEY IN THE WEAKENING
PROCESS. NEKI IS FORECAST TO WEAKEN TO A TROPICAL STORM BY 72
HOURS...THEN TO A DEPRESSION BY 120 HOURS WHEN THE SYSTEM WILL
LIKELY BE CLASSIFIED AS EXTRATROPICAL. 

ON ITS CURRENT TRACK...NEKI WILL BE IMPACTING THE PAPAHANAUMOKUAKEA
NATIONAL MONUMENT NEAR FRENCH FRIGATE SHOALS TONIGHT AND
FRIDAY...AND A HURRICANE WARNING REMAINS FOR THE MONUMENT FROM
NIHOA ISLAND TO MARO REEF. LARGE SWELLS FROM THE SOUTH WILL BUILD
AND CONDITIONS WILL CONTINUE TO DETERIORATE ACROSS PORTIONS OF THE
WARNING AREA TODAY AND TONIGHT...WITH SEAS GREATER THAN 20 FT AND
SURF UP 25 FT EXPECTED. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      22/2100Z 20.8N 166.3W    90 KT
 12HR VT     23/0600Z 21.8N 166.1W    85 KT
 24HR VT     23/1800Z 23.4N 165.7W    80 KT
 36HR VT     24/0600Z 25.0N 164.8W    75 KT
 48HR VT     24/1800Z 27.0N 163.6W    65 KT
 72HR VT     25/1800Z 31.0N 160.7W    55 KT
 96HR VT     26/1800Z 35.6N 156.8W    40 KT
120HR VT     27/1800Z 40.9N 151.9W    30 KT...EXTRATROPICAL
 
$$
FORECASTER BURKE