WTPA44 PHFO 050240

TCDCP4



HURRICANE JIMENA DISCUSSION NUMBER  38

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP132015

500 PM HST FRI SEP 04 2015



JIMENA CONTINUES TO WEAKEN AS PERSISTENT DEEP CONVECTION REMAINS

CONFINED TO NEAR THE CENTER WITH NO SIGN OF AN EYE. OUTFLOW HAS

IMPROVED IN THE WESTERN QUADRANT THIS AFTERNOON...BUT WITH WESTERLY

VERTICAL WIND SHEAR INCREASING TO MORE THAN 20 KT IN THE 0000 UTC

CIMSS ANALYSIS...THIS BURST OF OUTFLOW TO THE WEST SHOULD BE SHORT

LIVED. AN ASCAT PASS AT 1910 UTC DETECTED NUMEROUS AREAS OF 60 KT

WINDS IN NORTHWEST QUADRANT...AND GIVEN THE LOW BIAS OF ASCAT...

JIMENA WAS VERY LIKELY 10 KT STRONGER AT THE TIME. DVORAK CURRENT

INTENSITY ESTIMATES CAME IN AT 4.0/65 KT FROM ALL THE FIX

AGENCIES...WHILE CIMSS ADT WAS DOWN TO LESS THAN 60 KT. THUS...THE

INITIAL INTENSITY FOR THIS ADVISORY IS LOWERED TO 65 KT.



THE INITIAL MOTION REMAINS A SLOW NORTH-NORTHWEST...OR 330

DEGREES...AT 3 KT. JIMENA WILL CONTINUE ON A SIMILAR TRACK WITH A

RATHER SLOW FORWARD MOTION OVER THE NEXT TWO TO THREE DAYS. THIS

MOTION WILL BE INDUCED BY A MID TO UPPER LEVEL TROUGH PARKED JUST

WEST OF HAWAII THAT WILL MAINTAIN A WEAKNESS IN THE LOW LEVEL RIDGE

CENTERED OVER 1000 MILES NORTH OF JIMENA. THE GUIDANCE IS REMAINS

TIGHTLY CLUSTERED DURING THIS TIME BUT CONTINUES TO DIVERGE

SIGNIFICANTLY ON DAYS FOUR AND FIVE. THIS MODEL DISAGREEMENT HINGES

UPON THE DEVELOPMENT OF A RIDGE ALOFT OVER AND NORTH OF HAWAII

MONDAY NIGHT AND TUESDAY. THE OPERATIONAL GFS AND ECMWF REMAIN

NOTABLE SOUTHERN OUTLIERS...WHILE THE OFFICIAL TRACK CARRIES JIMENA

WESTWARD...CLOSE TO TVCN AND SOUTH OF THE GFS ENSEMBLE CONSENSUS ON

DAYS FOUR AND FIVE. THE OFFICIAL FORECAST WAS CHANGED LITTLE FROM

THE PREVIOUS PACKAGE ASIDE FROM AN INCREASE IN FORWARD SPEED ON DAY

FIVE.



CONTINUED WEAKENING IS EXPECTED THROUGH THE FORECAST PERIOD.

WESTERLY VERTICAL WIND SHEAR OF 20 KT OR MORE WILL PERSIST THROUGH

THE NEXT THREE DAYS THEN SHIFT OUT OF THE NORTHWEST ON DAYS FOUR

AND FIVE. THIS SHOULD CONTINUE TO DISRUPT THE OUTFLOW AND LEAD TO

CONTINUED SLOW WEAKENING. THE INTENSITY FORECAST CLOSELY FOLLOWS

THE PRIOR FORECAST TREND AND IS IN GOOD AGREEMENT WITH ICON AND

HWRF. HOWEVER...NOTABLE DIFFERENCES REMAIN IN THE GUIDANCE. THE GFS

AND THE ECMWF MAINTAIN A STRONGER CYCLONE...WHILE SHIPS AND LGEM

WEAKEN JIMENA AT A MUCH FASTER RATE.







FORECAST POSITIONS AND MAX WINDS



INIT  05/0300Z 20.3N 145.6W   65 KT  75 MPH

 12H  05/1200Z 21.0N 146.0W   60 KT  70 MPH

 24H  06/0000Z 22.0N 146.6W   55 KT  65 MPH

 36H  06/1200Z 23.0N 147.4W   55 KT  65 MPH

 48H  07/0000Z 23.9N 148.5W   50 KT  60 MPH

 72H  08/0000Z 24.8N 150.8W   45 KT  50 MPH

 96H  09/0000Z 24.8N 153.6W   40 KT  45 MPH

120H  10/0000Z 24.6N 157.0W   30 KT  35 MPH



$$

FORECASTER WROE