956 
 WTPA42 PHFO 251500
 TCDCP2
 
 TROPICAL STORM NEKI DISCUSSION NUMBER  28
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
 500 AM HST SUN OCT 25 2009
 
 THE LOW-LEVEL CIRCULATION OF NEKI APPEARS TO BE DECOUPLING FROM ITS 
 ASSOCIATED DEEP CONVECTION. THE CUMULONIMBUS CLOUDS...WHICH HAD BEEN 
 RATHER PERSISTENT LAST EVENING...ARE NOW PULSING THIS MORNING. THESE 
 SIGNS OF A LESS HEALTHY TROPICAL CYCLONE ARE UNDERSTANDABLE WHEN 
 CONSIDERING THE LATEST UW/CIMSS ESTIMATE OF ENVIRONMENTAL VERTICAL 
 WIND SHEAR IN THE VICINITY OF NEKI IS NOW A STRONG 31 KT FROM DUE 
 WEST. THESE HOSTILE ENVIRONMENTAL CONDITIONS ARE MAINLY THE RESULT 
 OF A LARGE UPPER TROPOSPHERIC TROUGH LOCATED JUST WEST NORTHWEST OF 
 NEKI.
  
 A 1023 MB SURFACE HIGH IS LOCATED NEAR 38N 165W...OR ABOUT 825 NM 
 NORTH OF NEKI. THE PRESENCE OF THIS ANTICYCLONE...WHICH IS MOVING 
 RAPIDLY TOWARD THE NORTHEAST...HAS DISRUPTED NEKI/S NORTHWARD MOTION 
 SINCE SATURDAY AFTERNOON. AT THE SAME TIME...THE DECOUPLING OF THE 
 LOW LEVEL CENTER DUE TO THE STRONG SHEAR ALLOWED THE SURFACE 
 SIGNATURE OF NEKI TO BEGIN DRIFTING TOWARD THE WEST LAST NIGHT. THIS 
 SLOW WESTWARD DRIFT WAS ALSO SUGGESTED IN THE LATEST POSITION 
 ESTIMATES PROVIDED BY THE SATELLITE ANALYSTS AT SAB...PHFO AND JTWC. 
 IT ALSO APPEARS THAT NEKI MAY HAVE COMPLETED A SMALL ANTICYCLONIC 
 LOOP SATURDAY NIGHT. FOR THIS ADVISORY...HAVE INDICATED NEKI/S 
 CURRENT MOTION IS 290 DEGREES AT 5 KT. THE CURRENT INTENSITY 
 ESTIMATES FROM THE SAME FIX AGENCIES RANGED FROM 2.5 TO 3.0. DUE TO 
 THESE INTENSITY ESTIMATES AND THE OBVIOUS DETERIORATION OF THE 
 TROPICAL STORM IN SATELLITE IMAGERY...HAVE WEAKENED NEKI TO 45 KT 
 FOR THE INITIAL INTENSITY IN THIS ADVISORY.
  
 AFTER THE SURFACE HIGH FAR NORTH OF NEKI SLIPS RAPIDLY AWAY TO THE 
 NORTHEAST LATER TODAY...THE INDIVIDUAL AND CONSENSUS TRACK GUIDANCE 
 CONTINUE TO SHOW THE SYSTEM WILL BEGIN TO MOVE SLOWLY TOWARD THE 
 NORTH NORTHWEST BY EARLY THIS AFTERNOON. THE GUIDANCE THEN MOVES 
 NEKI AT A SLIGHTLY FASTER FORWARD SPEED TOWARD THE NORTH LATER 
 TONIGHT. AT THE SAME TIME...NEKI IS FORECAST TO CONTINUE MOVING OVER 
 COOLER SEA SURFACE TEMPERATURES AND LOWER OCEAN HEAT CONTENT VALUES 
 TODAY AND TONIGHT. THE COOLING TREND OF THE UNDERLYING OCEAN 
 COMBINED WITH STRONG VERTICAL WIND SHEAR CONTINUES TO SUPPORT 
 ADDITIONAL WEAKENING LATER TODAY AND TONIGHT. 
 
 AS IN THE PREVIOUS FORECAST...AN EXTRATROPICAL TRANSITION IS 
 EXPECTED TO BEGIN BY MID-DAY MONDAY WHEN A LARGE AMPLITUDE UPPER 
 LEVEL TROUGH AND A STRONG SURFACE FRONT BEGIN TO INTERACT WITH NEKI. 
 THESE FEATURES WILL LIKELY CAUSE NEKI TO BEGIN ACCELERATING RAPIDLY 
 TOWARD THE NORTH NORTHEAST BY MONDAY AFTERNOON. A COMPLETE 
 TRANSITION TO AN EXTRATROPICAL GALE LOW IS EXPECTED BY LATE MONDAY 
 NIGHT. NOTE...DO NOT BE SURPRISED IF NEKI IS COMPLETELY SHEARED 
 BEYOND RECOGNITION...AS THE GFS AND ECMWF MODELS INDICATE...MONDAY 
 NIGHT WHEN IT ENCOUNTERS THE STRONG WESTERLIES AND IS ABSORBED BY 
 THE MID-LATITUDE SYSTEM OVER THE NORTH CENTRAL PACIFIC OCEAN.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      25/1500Z 24.8N 164.6W    45 KT
  12HR VT     26/0000Z 25.7N 165.0W    40 KT
  24HR VT     26/1200Z 27.5N 165.2W    35 KT
  36HR VT     27/0000Z 30.9N 164.3W    35 KT...BECOMING EXTRATROPICAL
  48HR VT     27/1200Z 37.2N 161.0W    35 KT...EXTRATROPICAL
  
 $$
 FORECASTER HOUSTON