307 
 WTPA41 PHFO 140857
 TCDCP1
 
 TROPICAL STORM PALI DISCUSSION NUMBER  28
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP012016
 1100 PM HST WED JAN 13 2016
  
 PALI CONTINUES ON A SIGNIFICANT WEAKENING TREND THAT BEGAN YESTERDAY
 AFTERNOON...WITH RAPID WEAKENING OBSERVED OVER THE PAST 12 HOURS.
 ASIDE FROM THE RECENT DEVELOPMENT OF AN ISOLATED CLUSTER OF
 THUNDERSTORMS NORTHEAST OF THE CENTER...INFRARED SATELLITE IMAGES
 SHOW THAT ASSOCIATED DEEP CONVECTION IS WANING...WITH COLD CLOUD
 TOPS STEADILY WARMING AND DIMINISHING IN AREA. RECENT MICROWAVE
 OVERPASSES INCLUDE A 0437Z AMSU-B PASS AND A 0628Z SSMIS PASS...AND
 BOTH REVEALED LITTLE IN THE WAY OF ORGANIZED STRUCTURE WITHIN THE
 DISSIPATING CONVECTION. SUBJECTIVE DVORAK INTENSITY ESTIMATES
 CONTINUE TO DROP RAPIDLY...WITH DATA-T VALUES DIFFICULT TO DETERMINE
 DUE TO THE LACK OF CONVECTION. REGARDLESS...PHFO/SAB/PGTW ALL
 DERIVED FINAL-T VALUES OF 2.5/35 KT...WITH CURRENT INTENSITY
 ESTIMATES RANGING FROM 45 TO 55 KT...DUE TO DVORAK CONSTRAINTS.
 BLENDING THIS DATA YIELDS A CURRENT INTENSITY ESTIMATE OF 40 KT FOR
 THIS ADVISORY. 
 
 DUE TO UNCERTAINTY IN THE CENTER LOCATION...OR EVEN IT/S CONTINUED
 EXISTENCE...THE INITIAL MOTION ESTIMATE OF 205/6 KT IS STRONGLY
 BASED ON EXTRAPOLATION OF PREVIOUS POSITION ESTIMATES. PALI REMAINS
 SOUTHEAST OF A DEEP LAYER ANTICYCLONE THAT HAS A CORRESPONDING RIDGE
 THAT EXTENDS EAST ALONG 17N. ALTHOUGH SOME DIFFERENCES ARE NOTED IN
 THE FORECAST FORWARD SPEED OF PALI...LATEST TRACK GUIDANCE IS IN
 REASONABLE AGREEMENT WITH IT/S GENERAL MOTION. THE EXPECTATION IS
 THAT THE RIDGE TO THE NORTH WILL REMAIN THE PRIMARY STEERING
 MECHANISM...AND THE CYCLONE WILL MAKE A BROAD ARC AS IT GRADUALLY
 TRANSITIONS TO A SOUTHWESTWARD...AND THEN WESTWARD MOTION. THE
 OFFICIAL TRACK FORECAST IS ESSENTIALLY AN UPDATE OF THE PREVIOUS...
 AND LIES CLOSE TO THE TVCN...WITH THE ONLY CHANGE BEING A SLIGHT
 DECREASE IN FORWARD SPEED BEYOND 48 HOURS.
 
 OCEAN HEAT CONTENT IS SUFFICIENTLY WARM ALONG THE FORECAST TRACK TO
 SUPPORT A STRONG CYCLONE. HOWEVER...SOUTH TO SOUTHWESTERLY SHEAR
 BETWEEN 20 AND 25 KT AND PALI/S PROXIMITY TO THE EQUATOR ARE
 EXPECTED TO RESULT IN CONTINUED WEAKENING IN THE SHORT TERM...WITH
 PALI BECOMING A DEPRESSION ON THURSDAY. THE ULTIMATE QUESTION FOR
 PALI HINGES ON WHETHER OR NOT IT CAN SURVIVE THESE NEGATIVE
 INFLUENCES IN THE SHORT TERM TO RE-STRENGTHEN IN THE LATER FORECAST
 PERIODS...WHEN SHEAR IS FORECAST TO RELAX AS PALI SLOWLY GAINS
 LATITUDE. MOST OF THE INTENSITY GUIDANCE INDICATES THAT THIS WILL
 OCCUR WEST OF THE DATE LINE ON DAYS 4 AND 5...WITH PALI FORECAST TO
 BECOME A STRONG TROPICAL STORM BY SHIPS AND IVCN. IN CONTRAST...THE
 UPDATED INTENSITY FORECAST INDICATES LITTLE CHANGE IN STRENGTH IN
 THE LATER PERIODS...MAINLY DUE TO THE INCREASING POTENTIAL THAT PALI
 DISSIPATES BEFORE EVER CROSSING THE DATE LINE...AS DEPICTED BY THE
 LATEST GFS GUIDANCE. 
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  14/0900Z  2.3N 172.5W   40 KT  45 MPH
  12H  14/1800Z  1.9N 173.3W   30 KT  35 MPH
  24H  15/0600Z  1.5N 174.5W   30 KT  35 MPH
  36H  15/1800Z  1.3N 175.7W   30 KT  35 MPH
  48H  16/0600Z  1.3N 177.0W   30 KT  35 MPH
  72H  17/0600Z  1.5N 179.5W   30 KT  35 MPH
  96H  18/0600Z  2.0N 177.5E   30 KT  35 MPH
 120H  19/0600Z  3.0N 174.5E   30 KT  35 MPH
  
 $$
 
 FORECASTER BIRCHARD
 

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