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 WTPA44 PHFO 041454
 TCDCP4
 
 HURRICANE JIMENA DISCUSSION NUMBER  36
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP132015
 500 AM HST FRI SEP 04 2015
  
 JIMENA CONTINUES TO STRUGGLE IN AN INCREASINGLY HOSTILE ENVIRONMENT 
 EARLY THIS MORNING. THERE IS NO EYE EVIDENT...AND DEEP CONVECTION IS 
 CONFINED PRIMARILY IN A RELATIVELY SMALL AREA IN THE NORTHEASTERN 
 SEMICIRCLE OF THE INNER CORE OF THE HURRICANE ACCORDING TO 1150Z 
 AMSU IMAGERY. THE LATEST ESTIMATE OF ENVIRONMENTAL VERTICAL WIND 
 SHEAR IN THE VICINITY OF JIMENA ACCORDING TO UW-CIMSS IS 16 KT FROM 
 245 DEGREES AND 12 KT FROM 285 DEGREES BASED ON THE SHIPS GUIDANCE. 
 IN ADDITION TO SHEAR BEING A LIKELY CULPRIT IN THE DEGRADATION OF 
 JIMENA...WATER VAPOR IMAGERY STRONGLY SUGGESTS THAT VERY DRY IS 
 BEING ENTRAINED INTO THE SYSTEM. ALSO...EVEN THOUGH THE OUTFLOW 
 ALOFT WAS RATHER IMPRESSIVE EARLIER TONIGHT...IT NOW APPEARS TO BE 
 SHOWING SOME RESTRICTIONS IN THE WESTERN QUADRANT. THE MOST RECENT 
 SUBJECTIVE DVORAK ESTIMATES OF CURRENT INTENSITY WERE 4.5/77 KT FROM 
 PHFO AND JTWC...AND 4.0/65 KT FROM SAB. THE LATEST UW-CIMSS ADT 
 INTENSITY ESTIMATE IS 4.3/72 KT. BASED ON A BLEND OF THESE INTENSITY 
 ESTIMATES...WE HAVE LOWERED THE INITIAL INTENSITY TO 75 KT.
  
 JIMENA REMAINS IN AN AREA OF WEAK STEERING...AND THE CURRENT MOTION 
 IS 310/04 KT. THERE IS A MID LEVEL ANTICYCLONE TO THE EAST-SOUTHEAST 
 OF JIMENA NEAR 16N 135W. THERE IS ALSO MID LEVEL RIDGE EXTENDING 
 FROM ANOTHER ANTICYCLONE NEAR 36N 155W DOWN TO 22N 153W. SINCE... 
 JIMENA IS SANDWICHED BETWEEN THESE FEATURES...IT APPEARS THAT 
 BETA-DRIFT MAY BE ONE OF THE PRIMARY STEERING MECHANISMS. THIS WEAK 
 STEERING WILL LIKELY CONTINUE THROUGH TONIGHT. FROM SATURDAY INTO 
 SUNDAY...THE WEAK STEERING PATTERN WILL PERSIST AS A MID LEVEL RIDGE 
 TO THE EAST BUILDS TO THE SOUTHEAST AND SOUTH OF JIMENA. THIS IS 
 EXPECTED TO RESULT IN A SLIGHTLY FASTER MOTION TOWARD THE 
 NORTH-NORTHWEST. BY MONDAY AND TUESDAY...THE MID LEVEL RIDGING TO 
 THE NORTH IS FORECAST TO STRENGTHEN...AND JIMENA WILL LIKELY TURN 
 TOWARD THE WEST. THE LATEST FORECAST IS CLOSE TO THE PREVIOUS 
 THROUGH 72 HOURS. THE FORECAST TRACK IS NUDGED SLIGHTLY TO THE RIGHT 
 COMPARED WITH THE PREVIOUS FORECAST ON DAYS 4 AND 5. THIS FORECAST 
 TRACK IS VERY CLOSE TO A BLEND BETWEEN THE TVCN AND GFEX CONSENSUS 
 GUIDANCE THROUGH DAY 4...AND THE GFEX ON DAY 5. NOTE THAT THE MODEL 
 SPREAD IS FAIRLY SMALL THROUGH 72 HOURS...WITH A MUCH WIDER SPREAD 
 ON DAYS 4 AND 5. THEREFORE...THERE REMAINS A GREAT DEAL OF 
 UNCERTAINTY IN THE TRACK FORECAST AS THIS SYSTEM MOVES TO A POSITION 
 NORTH-NORTHEAST OF THE MAIN HAWAIIAN ISLANDS.
  
 THE LATEST INTENSITY FORECAST CONTINUES TO SHOW GRADUAL...BUT STEADY 
 WEAKENING. THIS IS PRIMARILY DUE TO THE EFFECTS OF MODERATE 
 WEST-SOUTHWEST TO WEST SHEAR DURING THE NEXT 18-24 HOURS. BEYOND 24 
 HOURS...THE SHEAR STEADILY INCREASES...WHILE SEA SURFACE 
 TEMPERATURES AND OCEAN HEAT CONTENT VALUES GRADUALLY DECREASE. THE 
 LATEST INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS...AND VERY 
 CLOSE TO THE IVCN CONSENSUS...BUT CONTINUES TO SHOW LESS WEAKENING 
 THAN THE LATEST SHIPS GUIDANCE. 
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  04/1500Z 19.7N 145.1W   75 KT  85 MPH
  12H  05/0000Z 20.2N 145.4W   70 KT  80 MPH
  24H  05/1200Z 20.9N 145.8W   65 KT  75 MPH
  36H  06/0000Z 22.0N 146.3W   60 KT  70 MPH
  48H  06/1200Z 23.2N 147.1W   55 KT  65 MPH
  72H  07/1200Z 24.9N 149.2W   50 KT  60 MPH
  96H  08/1200Z 25.0N 151.0W   45 KT  50 MPH
 120H  09/1200Z 25.0N 152.5W   35 KT  40 MPH
  
 $$
 FORECASTER HOUSTON