355 
 WTPA42 PHFO 260245
 TCDCP2
 
 TROPICAL STORM NEKI DISCUSSION NUMBER  30
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
 500 PM HST SUN OCT 25 2009
 
 NEKI IS SLOWLY SPINNING DOWN AS IT INITIALLY MOVES WESTWARD. USING
 2330 UTC IMAGERY...PHFO AND JTWC BOTH GAVE CI VALUES OF 2.5. SAB
 DID THE SAME WITH 0000 UTC IMAGERY. SINCE THE LOW LEVEL CIRCULATION
 CENTER CONTINUES TO MOVE FARTHER AWAY FROM DEEP CONVECTION...AND
 BECAUSE THIS CENTER IS BEGINNING TO LOSE DEFINITION ALONG ITS NORTH
 SIDE...INITIAL NEKI INTENSITY THIS TIME IS DECREASED TO 40 KT. THE
 INITIAL NORTHEAST QUADRANT GALE RADIUS HAS BEEN DECREASED TO 165
 NM...WITH THE RADIUS CONTRACTED TO 140 NM AT TAU 12...THEN MATCHED
 WITH SMALLER RADII SET IN THE PREVIOUS PACKAGE FOR ALL SUBSEQUENT
 TAU.
  
 SINCE 0000 UTC...SATELLITE LOOP SHOWS NEKI IS MOVING ALMOST DUE WEST 
 AFTER MOVING NORTHWEST DURING THE PREVIOUS 6 HOURS. INITIAL MOTION 
 IS SET AT 275 DEGREES AT 5 KT...BUT THIS IS REALLY AN AVERAGE 3 HOUR 
 MOTION SINCE 0000 UTC. INSTANTANEOUS 1 HOUR MOTION AT 0130 UTC WOULD 
 SUGGEST A TRACK FARTHER NORTH OF DUE WEST...BUT THIS MAY BE DUE TO 
 WOBBLING OR TO AN OPTICAL ILLUSION CAUSED BY THE LOSS OF DEFINITION 
 ON THE NORTHERN FLANK OF THE CENTER. THE 5 KT INITIAL SPEED IS A TAD 
 FASTER THAN THAT SEEN 6 HOURS AGO. 
  
 THE 0000 UTC UW/CIMSS VERTICAL SHEAR PRODUCT SHOWS ABOUT 21 KT OF 
 WESTERLY SHEAR...A DROP FROM ABOUT 23 KT NOTED AT 1800 UTC...AND 
 FROM 31 KT NOTED AT 1200 UTC. HOWEVER THIS SHEAR...SUPPLIED BY A 
 LARGE UPPER TROPOSPHERIC TROUGH LOCATED JUST WEST NORTHWEST OF 
 NEKI...REMAINS STRONG ENOUGH TO BE DETRIMENTAL TO THE HEALTH OF THIS 
 SYSTEM. NEKI SITS RIGHT ON THE 26 DEGREE C SST ISOTHERM...SO IT 
 SEEMS CLEAR THAT NEKI WOULD NOT INTENSIFY EVEN IF IT WERE TO SIT 
 STILL. IN SPITE OF CONTINUED SLOW MOVEMENT TO THE WEST...TRACK 
 GUIDANCE ALMOST UNANIMOUSLY SWINGS NEKI TOWARD THE NORTH 
 TONIGHT...THEN TOWARD THE NORTHEAST MONDAY AND AFTERWARD. THE 
 FORECAST TRACK IS SHIFTED AGAIN TO THE LEFT FROM THE PREVIOUS 
 TRACK...THIS TIME AT ALL TAU...TO RECONCILE THE CURRENT WESTERLY 
 MOVEMENT WITH THE FORECAST SWING TO THE NORTH. THIS TRACK WILL TAKE 
 NEKI OVER COOLER WATER AND INTO THE PATH OF INCREASING SHEAR...SO 
 GRADUAL WEAKENING IS EXPECTED.
  
 NEKI IS EXPECTED TO UNDERGO EXTRATROPICAL TRANSITION BEYOND 36 HOURS
 AS A LARGE AMPLITUDE UPPER LEVEL TROUGH AND A STRONG SURFACE FRONT
 BEGIN TO INTERACT WITH IT. THIS INTERACTION WILL ALSO CAUSE NEKI TO
 ACCELERATE AS IT MOVES TOWARDS THE NORTHEAST. THE TRANSITION FROM
 TROPICAL STORM TO EXTRATROPICAL GALE SHOULD BE COMPLETE BY MIDDAY
 TUESDAY.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      26/0300Z 25.0N 165.3W    40 KT
  12HR VT     26/1200Z 26.8N 165.5W    40 KT
  24HR VT     27/0000Z 31.0N 163.7W    35 KT
  36HR VT     27/1200Z 36.7N 160.9W    35 KT...BECOMING EXTRATROPICAL
  48HR VT     28/0000Z 43.1N 157.3W    35 KT...EXTRATROPICAL
   
 $$
 FORECASTER POWELL