314 
 WTPA44 PHFO 040255
 TCDCP4
 
 HURRICANE JIMENA DISCUSSION NUMBER  34
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP132015
 500 PM HST THU SEP 03 2015
  
 THE CLOUD-FILLED EYE OF JIMENA HAS BEEN WOBBLING TOWARD THE
 NORTHWEST AT A VERY SLOW RATE OF SPEED SINCE THE PREVIOUS ADVISORY.
 THE OVERALL SATELLITE PRESENTATION OF THE HURRICANE HAS DEGRADED
 SLIGHTLY OVER THE COURSE OF THE DAY...BUT IMPRESSIVE OUTFLOW ALOFT
 CONTINUES...ESPECIALLY IN THE NORTHERN SEMICIRCLE. A 2342Z SSMI
 OVERPASS INDICATED THAT THE EYE WALL ERODED IN THE SOUTHWEST 
 QUADRANT...WHILE COOLING EYE TEMPERATURES LED TO LOWER DVORAK 
 INTENSITY ESTIMATES. CURRENT INTENSITY ESTIMATES FROM PHFO/SAB/JTWC 
 ALL CAME IN AT 4.5/77 KT...WITH DATA-T VALUES OF T4.0/65 KT. 
 UW-CIMSS ADT CURRENT INTENSITY ESTIMATES CONTINUE NEAR 5.0/90 KT... 
 AND BASED ON A BLEND OF THIS DATA AND THE SATELLITE TRENDS...THE 
 INITIAL INTENSITY HAS BEEN LOWERED SLIGHTLY TO 85 KT. A 1930Z ASCAT 
 PASS WAS USED TO REFINE THE TROPICAL STORM FORCE RADII IN THE 
 EASTERN SEMICIRCLE.
  
 JIMENA REMAINS EMBEDDED IN AN AREA OF NEARLY NON-EXISTENT STEERING
 FLOW...AND IT REMAINS UNCLEAR AS TO WHAT SYNOPTIC SCALE FEATURE IS
 DRIVING THE CURRENT MOTION OF 310/03 KT. WEAK DEEP-LAYER HIGHS ARE
 CENTERED TO THE EAST AND TO THE DISTANT NORTH-NORTHWEST OF
 JIMENA...AND GIVEN THE CURRENT OBSERVED MOTION...IT IS LIKELY
 THAT BETA-DRIFT REMAINS THE PRIMARY STEERING MECHANISM THIS
 AFTERNOON. WEAK STEERING WILL PERSIST FOR THE NEXT 24 HOURS OR SO...
 AND A SLOW DRIFT TO THE NORTHWEST IS EXPECTED. FROM SATURDAY INTO
 SUNDAY...THE COMPLEX STEERING PATTERN WILL PERSIST...AS THE HIGH TO
 THE NORTH TEMPORARILY RECEDES NORTHWARD...WHILE THE RIDGE TO THE
 EAST BUILDS TO THE SOUTHEAST AND SOUTH OF THE CYCLONE. THIS IS
 EXPECTED TO RESULT IN A SLIGHTLY FASTER MOTION TOWARD THE NORTH- 
 NORTHWEST. ON MONDAY AND TUESDAY...THE RIDGE TO THE NORTH IS
 FORECAST TO STRENGTHEN...AND JIMENA WILL RESPOND BY TURNING TOWARD
 THE WEST. THE UPDATED OFFICIAL FORECAST IS A LITTLE SLOWER THAN THE
 PREVIOUS THROUGH THE FIRST 36 HOURS...IS ESSENTIALLY UNCHANGED
 FROM 48 THROUGH 96 HOURS...LIES SOUTH OF THE PREVIOUS AT DAY 5...AND 
 IS VERY CLOSE TO THE GFEX CONSENSUS.  
  
 THE INTENSITY FORECAST CONTINUES TO ANTICIPATE GRADUAL BUT STEADY
 WEAKENING THROUGH THE FORECAST PERIOD...PRIMARILY DUE TO THE EFFECTS
 OF SOUTHWESTERLY SHEAR. MODERATE SHEAR...NEAR 10 TO 15 KT...IS
 EXPECTED TO PERSIST OVER THE NEXT 24 HOURS OR SO...AFTER WHICH
 TIME IT STEADILY INCREASES TO NEAR 25 KT BY DAY 3. THE FORECAST
 TRACK ALSO TAKES JIMENA OVER GRADUALLY DECREASING WATER TEMPERATURES 
 AND OCEAN HEAT CONTENT. THE UPDATED INTENSITY FORECAST IS SIMILAR TO 
 THE PREVIOUS AND IVCN INTENSITY CONSENSUS...BUT CONTINUES TO BE 
 HIGHER THAN THAT INDICATED BY SHIPS GUIDANCE.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  04/0300Z 19.2N 144.5W   85 KT 100 MPH
  12H  04/1200Z 19.7N 144.8W   80 KT  90 MPH
  24H  05/0000Z 20.3N 145.1W   75 KT  85 MPH
  36H  05/1200Z 21.0N 145.4W   70 KT  80 MPH
  48H  06/0000Z 22.2N 145.9W   60 KT  70 MPH
  72H  07/0000Z 24.2N 147.1W   55 KT  65 MPH
  96H  08/0000Z 25.5N 148.5W   50 KT  60 MPH
 120H  09/0000Z 25.5N 150.0W   45 KT  50 MPH
  
 $$
 
 FORECASTER BIRCHARD