593 
 WTPA42 PHFO 220313
 TCDCP2
 
 HURRICANE NEKI DISCUSSION NUMBER  14
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
 500 PM HST WED OCT 21 2009
 
 AFTER RAPID INTENSIFICATION EARLIER TODAY...THE RATE OF
 INTENSIFICATION OF NEKI HAS SLOWED. FIXES FROM PHFO AND JTWC CAME
 IN AT 5.5...SAB REPORTED 6.0...AND CIMSS ADT CALCULATED 6.2. THE
 INITIAL INTENSITY IS INCREASED TO 105 KT...AN AVERAGE OF THE FIX
 AGENCIES. UPPER LEVEL OUTFLOW REMAINS GOOD IN MOST QUADRANTS DUE TO
 AN UPPER LEVEL ANTICYCLONE PARKED JUST SOUTH OF THE MAIN HAWAIIAN
 ISLANDS. HOWEVER...OUTFLOW ALONG THE WESTERN QUADRANT APPEARS TO BE
 PARTIALLY RESTRICTED DUE TO AN UPPER LEVEL TROUGH MOVING DOWN FROM
 THE NORTH. THIS IS PRODUCING INCREASING WEST-SOUTHWESTERLY WIND
 SHEAR OF 16 KT ACCORDING TO THE 0000 UTC CIMSS VERTICAL WIND SHEAR
 ESTIMATE. THIS SHEAR DOES NOT APPEAR TO BE AFFECTING THE CORE
 YET...AND SINCE NEKI SITS OVER 28 CELSIUS WATER...SOME ADDITIONAL
 STRENGTHENING IS POSSIBLE TONIGHT.
 
 THE INITIAL MOTION IS NOW TO THE DUE NORTH AT 8 KT TOWARD A WEAKNESS
 IN THE SUBTROPICAL RIDGE TO THE NORTH. THE RIDGE IS BEING ERODED BY 
 A FRONT MOVING OVER LISIANSKI AND ITS ASSOCIATED BROAD UPPER LEVEL
 TROUGH THAT HAS HAS EDGED SOUTHWARD TO 25N. 
 
 NEKI IS EXPECTED TO CONTINUE MOVING TO THE NORTH TOWARD THE WEAKNESS
 IN THE RIDGE THEN GRADUALLY SHIFT TO THE NORTHEAST FRIDAY NIGHT AS
 IT INTERACTS WITH THE UPPER LEVEL TROUGH. THE TRACK HAS AGAIN BEEN
 UDGED TO THE RIGHT AND NOW LIES ALONG THE RIGHT SIDE OF THE
 GUIDANCE ENVELOPE TO BE CLOSE TO THE WELL-PERFORMING HWRF AND GFDL
 MODELS THROUGH THE WEEKEND. 
 
 AS NEKI CONTINUES MOVING NORTHWARD TOWARD THE NEARLY STATIONARY
 UPPER LEVEL TROUGH...IT WILL ENCOUNTER GREATER VERTICAL WIND SHEAR
 THAT WILL INDUCE WEAKENING. THE RATE OF WEAKENING IS IN THE MIDDLE
 OF THE GUIDANCE ENVELOPE. THIS BRINGS NEKI TO A TROPICAL STORM BY
 DAY FIVE...BUT THE FATE OF NEKI WILL HINGE UPON ITS INTERACTION
 WITH A FRONT APPROACHING FROM THE NORTHWEST. BY DAY FIVE...THESE
 MODELS SUGGEST THAT NEKI MAY BE RACING OFF TO THE NORTHEAST AS IT
 INTERACTS WITH THE APPROACHING FRONT.
  
 ON THE CURRENT TRACK...NEKI WILL BE APPROACHING THE
 PAPAHANAUMOKUAKEA NATIONAL MONUMENT NEAR FRENCH FRIGATE SHOALS ON
 FRIDAY...AND A HURRICANE WARNING REMAINS FOR THE MONUMENT FROM NIHOA
 ISLAND TO MARO REEF. THE HURRICANE WATCH FROM MARO REEF TO
 LISIANSKI WITHIN THE MONUMENT HAS BEEN CHANGED TO A TROPICAL STORM
 WATCH AS THE TRACK HAS SHIFTED EASTWARD. LARGE SWELLS FROM THE
 SOUTH WILL BUILD TONIGHT AND CONDITIONS WILL DETERIORATE ACROSS
 PORTIONS OF THE WARNING AREA THURSDAY...WITH SEAS GREATER THAN 20
 FT AND SURF UP 25 FT EXPECTED.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      22/0300Z 18.7N 166.7W   105 KT
  12HR VT     22/1200Z 19.9N 166.6W   110 KT
  24HR VT     23/0000Z 21.4N 166.5W   105 KT
  36HR VT     23/1200Z 23.1N 166.3W    90 KT
  48HR VT     24/0000Z 24.8N 165.5W    80 KT
  72HR VT     25/0000Z 27.4N 163.5W    70 KT
  96HR VT     26/0000Z 29.9N 161.2W    65 KT
 120HR VT     27/0000Z 34.0N 158.9W    55 KT
  
 $$
 FORECASTER WROE