WTPA42 PHFO 200233
TCDCP2

TROPICAL STORM NEKI DISCUSSION NUMBER   6
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
500 PM HST MON OCT 19 2009

DEEP CONVECTION ASSOCIATED WITH NEKI HAS WEAKENED THROUGH THE DAY
BUT THE CIRCULATION REMAINS LARGE AND WELL-DEFINED. SEVERAL
RAINBANDS TO THE WEST...NORTHEAST AND SOUTHEAST AND THE LACK OF
SIGNIFICANT CENTRAL CONVECTION GIVE NEKI THE APPEARANCE OF A
WESTERN PACIFIC MONSOON DEPRESSION RATHER THAN A TYPICAL TROPICAL
CYCLONE. THE LOW LEVEL CENTER OF NEKI IS EXPOSED AND IS MOVING AT
15 KT TOWARD THE NORTHWEST. ALL OF THE SATELLITE FIX AGENCIES...
PHFO...SAB AND JTWC...GAVE NEKI A CI OF 2.5...OR 35 KT. THUS...THE
INITIAL INTENSITY WILL BE HELD AT 35 KT FOR THIS FORECAST PACKAGE.
 
TROPICAL STORM NEKI CONTINUES TO MOVE NORTHWESTWARD TO THE SOUTH OF
A WEAKNESS IN THE SUBTROPICAL RIDGE. MOST OF THE OBJECTIVE AIDS
REMAIN RELATIVELY CONSISTENT WITH A GENERAL NORTHWESTWARD TRACK
PROJECTED OVER THE NEXT 36 HOURS. THE NOGAPS SOLUTION HAS SHIFTED
NORTHEAST TO BECOME MORE IN LINE WITH GFS...ECMWF...GFDL AND HWRF. 
UKMET REMAINS AS THE LEFT-MOST OUTLIER...SHOWING A FASTER TRACK
TOWARD THE WEST-NORTHWEST. AT 36 TO 48 HOURS...A PASSING TROUGH IN
THE WESTERLIES IS EXPECTED TO CAUSE A BREAK IN THE SUBTROPICAL
RIDGE AND A SIGNIFICANT WEAKNESS IN THE STEERING CURRENT.  THIS
WILL BE PRODUCING A SLOWER FORWARD SPEED IN NEKI/S MOTION AND A
NORTH-NORTHWESTWARD PATH UNTIL THE RIDGE REDEVELOPS AFTER 96 HOURS.
THE FORECAST TRACK HAS BEEN SHIFTED A BIT TO THE NORTHEAST FROM THE
PREVIOUS PACKAGE AND LIES WITHIN THE MAIN CLUSTER OF DYNAMICAL
MODEL SOLUTIONS...MINUS THE UKMET.
  
INTENSIFICATION IS STILL EXPECTED TO OCCUR GIVEN THE FAVORABLE
ENVIRONMENTAL CONDITIONS.  CIMSS DATA SHOW VERTICAL SHEAR TO BE
FAVORABLE FOR DEVELOPMENT WITH A VALUE OF 2.6 M/S AT 20/0000 UTC.
SHEAR IS EXPECTED TO REMAIN WEAK ALONG THE FORECAST TRACK.  SEA
SURFACE TEMPERATURES ARE MORE THAN ADEQUATE AT VALUES RANGING FROM
JUST BELOW 28C TO NEARLY 29C. OCEANIC HEAT CONTENT IS ALSO EXPECTED
TO BE SUFFICIENT FOR DEVELOPMENT...OR AT LEAST NOT A LIMITING
FACTOR. THUS...DESPITE PRESENT APPEARANCES...THE FORECAST STILL
EXPECTS NEKI TO BECOME A HURRICANE BY 36 HOURS ASSUMING CENTRAL
DEEP CONVECTION CAN DEVELOP OVERNIGHT AND PERSIST.
 
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 WARRANT THE ISSUANCE OF A HURRICANE
WATCH SINCE THE LEAD TIME REQUIREMENT IS 48 HOURS IN THE CENTRAL
PACIFIC BASIN.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      20/0300Z 11.6N 161.0W    35 KT
 12HR VT     20/1200Z 12.9N 162.8W    40 KT
 24HR VT     21/0000Z 14.6N 164.9W    50 KT
 36HR VT     21/1200Z 16.0N 166.4W    65 KT
 48HR VT     22/0000Z 17.1N 167.0W    75 KT
 72HR VT     23/0000Z 19.0N 168.0W    85 KT
 96HR VT     24/0000Z 20.0N 169.5W    90 KT
120HR VT     25/0000Z 21.5N 172.0W    80 KT
 
$$
FORECASTER KODAMA