WTPA42 PHFO 201458
TCDCP2

TROPICAL STORM NEKI DISCUSSION NUMBER   8
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
500 AM HST TUE OCT 20 2009

NEKI HAS SHOWN IMPRESSIVE SIGNS OF INTENSIFICATION OVER THE PAST 12
HOURS. THE CLOUD TOPS OVER THE CENTER HAVE COOLED AND EXPANDED IN
AREA AND A 1043 UTC TRMM PASS SHOWED A PARTIAL EYEWALL ON THE
SOUTHEAST SIDE OF THE CENTER. THE 1200 UTC FIXES FROM PHFO...SAB
AND JTWC WERE 3.0...3.5 AND 3.5. TAKING INTO ACCOUNT THE IMPRESSIVE
MICROWAVE IMAGERY...WE HAVE MADE THE INITIAL INTENSITY 55 KT...
MATCHING THE MAJORITY OF THE DVORAK FIXES. 
 
TROPICAL STORM NEKI CONTINUES TO MOVE NORTHWESTWARD TO THE SOUTH OF
A WEAKNESS IN THE SUBTROPICAL RIDGE. THE OBJECTIVE AIDS ARE PRETTY
CONSISTENT IN SHOWING NEKI TURNING SLIGHTLY TO THE RIGHT AND
SLOWING AS A TROUGH MOVES EASTWARD TO THE NORTH OF THE STORM. AFTER
THE TROUGH PASSES...AND RIDGING ALOFT REBUILDS NORTHWEST OF THE
CYCLONE...THE TRACK TURNS BACK TOWARD THE WEST NORTHWEST. WE HAVE
KEPT THE TRACK VERY CLOSE TO THE PREVIOUS FORECAST. THE LATEST
FORECAST KEEPS NEKI WELL SOUTHWEST OF THE MAIN HAWAIIAN ISLANDS.
HOWEVER...THE TRACK ALSO TAKES THE CENTER OF NEKI CLOSE ENOUGH TO
JOHNSTON ISLAND TO CONTINUE A HURRICANE WATCH FOR THAT ISLAND.
TOMORROW WE MAY NEED TO CONSIDER A WATCH FOR PARTS OF THE
PAPAHANAUMOKUAKEA NATIONAL MARINE MONUMENT...NORTHWEST OF THE MAIN
HAWAIIAN ISLANDS.
 
THE FORECAST TRACK KEEPS NEKI OVER 28 DEGREE CELSIUS WATER FOR THE
NEXT 120 HOURS. SHIPS GUIDANCE SHOWS 10 KT NORTHEAST SHEAR DROPPING
TO ONLY 5 KT IN 24 HOURS. THESE ENVIRONMENTAL FACTORS SHOULD BE
FAVORABLE ENOUGH TO ALLOW NEKI TO CONTINUE INTENSIFYING. SHIPS
GUIDANCE SHOWS EXCEPTIONALLY HIGH PROBABILITIES OF RAPID
INTENSIFICATION. WE HAVE INCREASED THE RATE OF INTENSIFICATION IN
OUR FORECASTS AND NOW HAVE NEKI REACHING HURRICANE STRENGTH IN 12
HOURS.
 
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      20/1500Z 13.3N 163.3W    55 KT
 12HR VT     21/0000Z 14.7N 164.9W    65 KT
 24HR VT     21/1200Z 16.4N 166.5W    75 KT
 36HR VT     22/0000Z 17.8N 167.5W    85 KT
 48HR VT     22/1200Z 18.8N 168.1W    95 KT
 72HR VT     23/1200Z 20.4N 169.4W   105 KT
 96HR VT     24/1200Z 21.5N 171.5W   100 KT
120HR VT     25/1200Z 22.0N 174.0W    95 KT
 
$$
FORECASTER DONALDSON