WTPA42 PHFO 241515 CCA
TCDCP2

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

HOSTILE ATMOSPHERIC CONDITIONS CONTINUE TO AFFECT TROPICAL STORM 
NEKI EARLY THIS MORNING. THE LATEST UW/CIMSS ESTIMATE OF VERTICAL 
WIND SHEAR AFFECTING NEKI IS 23 KT FROM 246 DEGREES. THESE ADVERSE 
CONDITIONS ARE PARTIALLY DUE TO AN UPPER TROPOSPHERIC TROUGH... 
WHICH IS EVIDENT IMMEDIATELY TO THE WEST OF NEKI ACCORDING TO LOOPS 
OF WATER VAPOR IMAGERY AND SATELLITE DERIVED UPPER LEVEL WINDS. 
THERE IS ALSO A LARGE UPPER LEVEL ANTICYCLONE CENTERED NEAR 15N 
160W. THE OVERALL APPEARANCE OF THE TROPICAL STORM CONTINUES TO 
DETERIORATE THIS MORNING. AN IMPRESSIVE SWATH OF CIRRUS CLOUDS IS 
STREAMING MORE THAN 400 NM TOWARD THE NORTHEAST AWAY FROM THE 
REMAINING DEEP CONVECTION. THE OUTFLOW IN THE SOUTHWESTERN 
SEMICIRCLE OF THE STORM IS ALSO BEING IMPEDED DUE TO THE RELATIVELY 
STRONG UPPER LEVEL SOUTHWESTERLY WINDS. IN ADDITION TO THE HARSH 
ATMOSPHERIC ENVIRONMENT AFFECTING NEKI...IT IS ALSO MOVING OVER 
COOLER SEA SURFACE TEMPERATURES...WITH VALUES NEAR 26 TO 27 DEGREES 
C. OCEAN HEAT CONTENT VALUES ALSO CONTINUE TO DECREASE ACCORDING TO 
THE LATEST CIRA ANALYSIS. 
 
IT IS DIFFICULT TO FIND THE LOW LEVEL CIRCULATION CENTER OF TROPICAL 
STORM NEKI IN INFRARED SATELLITE IMAGERY. THERE IS A SPREAD IN THE 
POSITIONS FROM THE SATELLITE FIX AGENCIES...SAB...JTWC AND PHFO. 
NEKI CONTINUES TO MOVE RATHER SLOWLY...SO IT APPEARS TO BE CLOSE TO 
THE LATEST OFFICIAL POSITION. BASED ON THE LATEST TRACK...NEKI IS 
MOVING TOWARD 045 DEG AT 6 KT. CURRENT INTENSITY ESTIMATES YIELD 
ARE 3.0. A QUIKSCAT PASS FROM AROUND 0531 UTC INDICATED NEKI 
HAD SOME UNFLAGGED 50 KT WINDS EARLIER TONIGHT. THEREFORE...WILL 
DECREASE NEKI TO AN INITIAL INTENSITY OF 50 KT FOR THIS FORECAST. 
 
THE CURRENT TRACK FORECAST IS AN UPDATE OF THE PREVIOUS ONE WITH 
SUBTLE CHANGES MADE THROUGH 48 HOURS. WEAK STEERING CONDITIONS WILL 
LIKELY CONTINUE THROUGH THAT TIME PERIOD. NEKI IS FORECAST TO 
ACCELERATE BEYOND DAY 2 WHEN IT WILL LIKELY BE CAUGHT UP IN THE 
WESTERLIES WHEN A LARGE AMPLITUDE UPPER LEVEL TROUGH IS FORECAST TO 
DIG RAPIDLY TOWARD THE EAST SOUTHEAST. THE INTENSITY FORECAST 
CONTINUES TO REFLECT THE WEAKENING TREND THAT IS EVIDENT IN ALL OF 
THE GUIDANCE. HAVE KEPT GALE FORCE WINDS IN THE 72/96 HOUR PERIOD 
WHEN NEKI IS EXPECTED TO BE TRANSITIONING INTO AN EXTRATROPICAL 
SYSTEM OVER THE NORTHERN PACIFIC OCEAN. NOTE...SOME OF THE MODELS 
NOW INDICATE NEKI WILL BE SHEARED APART AND COMPLETELY LOSE ITS 
IDENTITY WITHIN 72-96 HOURS. THEREFORE...DO NOT BE SURPRISED IF IT 
IS NO LONGER IDENTIFIABLE IN 3 OR 4 DAYS.
 
WILL HAVE TO DETERMINE LATER THIS MORNING IF ADVERSE WEATHER 
CONDITIONS ARE BEGINNING TO SUBSIDE IN THE TROPICAL STORM WARNING 
AREA FROM NIHOA ISLAND TO FRENCH FRIGATE SHOALS. ATMOSPHERIC 
CONDITIONS HAVE IMPROVED ENOUGH WEST OF FRENCH FRIGATE SHOALS TO 
ALLOW THE CANCELLATION OF THE TROPICAL STORM WARNING FOR THAT AREA. 
NOTE THAT DUE TO CLOSE PROXIMITY OF NEKI...AND ITS SLOW FORWARD 
MOTION...ROUGH SEAS AND LARGE BREAKING WAVES WILL CONTINUE TO OCCUR 
ACROSS THE MOST OF THE PAPAHANAUMOKUAKEA NATIONAL MONUMENT FROM MARO 
REEF TO NIHOA ISLAND FOR MUCH OF TODAY.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      24/1500Z 24.3N 164.2W    50 KT
 12HR VT     25/0000Z 25.1N 163.7W    45 KT
 24HR VT     25/1200Z 26.3N 163.0W    45 KT
 36HR VT     26/0000Z 27.7N 162.5W    40 KT
 48HR VT     26/1200Z 30.0N 161.8W    35 KT
 72HR VT     27/1200Z 39.0N 158.0W    35 KT...BECOMING EXTRATROPICAL
 96HR VT     28/1200Z 45.0N 146.0W    35 KT...EXTRATROPICAL
 
$$
FORECASTER HOUSTON