875 
 WTPZ44 KNHC 241459
 TCDEP4
  
 HURRICANE HILARY DISCUSSION NUMBER  14
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092011
 800 AM PDT SAT SEP 24 2011
  
 HURRICANE HILARY IS EXHIBITING A PINHOLE EYE THIS MORNING AS
 EVIDENCED BY THE FIRST VISIBLE SATELLITE IMAGERY AS WELL AS AN
 0815Z AQUA MICROWAVE PASS.  A CONSENSUS OF THE TAFB/SAB SUBJECTIVE
 DVORAK CLASSIFICATIONS AND THE ADVANCED DVORAK TECHNIQUE FROM CIMSS
 SUGGESTS THAT 120 KT REMAINS THE INTENSITY.
  
 SOMEWHAT SURPRISINGLY...THE HURRICANE HAS BEEN JOGGING TOWARD THE
 SOUTHWEST DURING THE LAST FEW HOURS.  THIS MAY BE DUE TO A
 TROCHOIDAL OSCILLATION NOT UNCOMMONLY SEEN IN MAJOR HURRICANES.  A
 LONGER-TERM MOTION IS ANALYZED TO BE 270/10.  A MOTION TOWARD THE
 WEST OR WEST-NORTHWEST AT A SLIGHTLY SLOWER FORWARD SPEED IS
 EXPECTED DURING THE NEXT THREE DAYS AS HILARY IS STEERED ALONG THE
 SOUTH SIDE OF A DEEP-LAYERED RIDGE.  BY DAYS 4 AND 5...A WEAKNESS
 DEVELOPS IN THE RIDGE DUE TO A MID- TO UPPER-LEVEL LOW MOVING IN
 FROM THE NORTHWEST...WHICH IS CURRENTLY SEEN IN THE WATER VAPOR
 IMAGERY NEAR 23N140W.  HILARY SHOULD RESPOND BY TURNING SLOWLY
 NORTHWARD NEAR 115W ON THOSE DAYS.  ALL OF THE RELIABLE TRACK
 MODELS ARE IN MUCH BETTER AGREEMENT WITH THIS SCENARIO TODAY
 COMPARED TO YESTERDAY...AS NONE OF THE GUIDANCE ARE TAKING HILARY
 TO MEXICO WITHIN FIVE DAYS.  THE TRACK FORECAST IS SOMEWHAT SOUTH
 OF THE PREVIOUS ADVISORY BECAUSE OF THE SHORT-TERM MOTION CHANGE
 AND THEN JUST TO THE WEST OF THE PREVIOUS ADVISORY BY DAYS 4 AND
 5...IN AGREEMENT WITH THE MULTI-MODEL CONSENSUS.
  
 THE HURRICANE IS CURRENTLY IN A QUITE CONDUCIVE ENVIRONMENT OF LOW
 VERTICAL SHEAR...WARM WATERS...AND ABUNDANT MOISTURE.  THE CYCLONE
 IS EXPECTED TO REMAIN A MAJOR HURRICANE FOR THE NEXT TWO DAYS.
 AFTER WHICH...A DRIER AND MORE STABLE ATMOSPHERE MAY BEGIN SOME
 SIGNIFICANT WEAKENING OF HILARY.  BY THE END OF THE FORECAST
 PERIOD...STRONG VERTICAL SHEAR AND COOL SSTS SHOULD CAUSE AN EVEN
 QUICKER DECAY.  THE INTENSITY PREDICTION IS BASED UPON THE
 SHIPS/LGEM/GFDL MODEL CONSENSUS AND IS VERY SIMILAR TO THE PREVIOUS
 ADVISORY.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  24/1500Z 16.6N 106.2W  120 KT 140 MPH
  12H  25/0000Z 17.1N 107.6W  115 KT 135 MPH
  24H  25/1200Z 17.3N 109.3W  110 KT 125 MPH
  36H  26/0000Z 17.5N 110.9W  110 KT 125 MPH
  48H  26/1200Z 17.6N 112.4W  105 KT 120 MPH
  72H  27/1200Z 18.0N 115.0W   95 KT 110 MPH
  96H  28/1200Z 19.0N 116.0W   80 KT  90 MPH
 120H  29/1200Z 21.5N 116.0W   65 KT  75 MPH
  
 $$
 FORECASTER LANDSEA/STEWART