WTPA43 PHFO 040854

TCDCP3



TROPICAL DEPRESSION EIGHT-C DISCUSSION NUMBER   4

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP082015

1100 PM HST SAT OCT 03 2015



LAST-LIGHT VISIBLE AND MORE RECENT 11-3.9 MICRON FOG PRODUCT

SATELLITE IMAGERY CONTINUE TO CLEARLY SHOW THE EXPOSED LOW LEVEL

CIRCULATION CENTER /LLCC/ OF TROPICAL DEPRESSION EIGHT-C. ORGANIZED

DEEP CONVECTION HAS BEEN ABSENT NEAR THE LLCC FOR OVER 12 HOURS

NOW...WITH JUST ISOLATED THUNDERSTORMS LOCATED IN THE NORTHERN

SEMICIRCLE MORE THAN 150 MILES FROM THE CENTER AT PRESENT.

SUBJECTIVE DVORAK INTENSITY ANALYSES FROM PHFO AND JTWC WERE UNABLE

TO DETERMINE A DATA-T DUE TO THE LACK OF CONVECTION...WHILE CURRENT

INTENSITY ESTIMATES REMAINED AT 2.0/30 KT DUE TO CONSTRAINTS. SAB

HAS CEASED PROVIDING FIXES...AND THE LATEST UW-CIMSS ADT INTENSITY

ESTIMATE IS 25 KT. THE INITIAL INTENSITY WILL BE LOWERED TO 25 KT

FOR THIS ADVISORY. IF ORGANIZED CONVECTION DOES NOT DEVELOP AND

PERSIST NEAR THE LLCC SOON...EIGHT-C WILL LIKELY BE DESIGNATED AS A

POST-TROPICAL REMNANT LOW ON SUNDAY MORNING.



EIGHT-C HAS MOVED TO THE SOUTH-SOUTHEAST NEAR 5 KT DURING THE PAST

SEVERAL HOURS...AND RECENTLY SEEMS TO BE DRIFTING SLOWLY TO THE

EAST-SOUTHEAST. IT APPEARS THAT THE CYCLONE IS CONTINUING TO

MAKE A SLOW CYCLONIC LOOP. ALL OF THE RELIABLE GUIDANCE INSISTS THAT

EIGHT-C WILL COMMENCE A SLOW WEST-NORTHWEST MOTION ON SUNDAY...

WITH INCREASING FORWARD SPEED SUNDAY NIGHT AND MONDAY...AS A

STRONG LOWER/MID LEVEL RIDGE BUILDS NORTH OF THE CYCLONE. GLOBAL

MODELS FORECAST THIS RIDGE TO SHIFT SLOWLY WESTWARD WITH TIME...

WHICH SHOULD KEEP EIGHT-C ON A STEADY WEST-NORTHWEST TRACK THROUGH

120 HOURS. THE NEW OFFICIAL FORECAST IS SHIFTED SLIGHTLY TO THE

NORTH OF THE PREVIOUS TRACK...AND IS A COMPROMISE BETWEEN THE

PREVIOUS TRACK AND THE TVCN MODEL CONSENSUS.



STRONG SOUTHERLY VERTICAL WIND SHEAR CONTINUES TO IMPACT THE

DEPRESSION...WITH SHEAR MAGNITUDE ESTIMATED AT 23 KT BY SHIPS AND

28 KT BY UW-CIMSS. THIS SHEAR IS CAUSED BY THE FLOW ALOFT BETWEEN

AN UPPER LEVEL ANTICYCLONE TO THE EAST AND A TROUGH TO THE WEST OF

THE DEPRESSION. SHIPS FORECASTS THE SHEAR TO REMAIN FAIRLY STRONG

FOR ANOTHER 18 TO 24 HOURS...THEN DECREASE THEREAFTER. ALTHOUGH

THE DEPRESSION WILL CONTINUE MOVING OVER WARM SEA SURFACE

TEMPERATURES OF 29-30C...AND THE SHEAR IS FORECAST TO LESSEN AFTER

24 HOURS...THE SHIPS...GFS/ECMWF AND HWRF SHOW LITTLE INTENSITY

CHANGE THROUGH THE NEXT 48 HOURS. WHILE THE SHIPS DEPICTS SOME

GRADUAL INTENSIFICATION THEREAFTER...THE GLOBAL MODELS AND HWRF KEEP

THREE-C AS A WEAK LOW...AND THE OFFICIAL FORECAST WILL CARRY A 25 KT

REMNANT LOW THROUGH 120 HOURS.





FORECAST POSITIONS AND MAX WINDS



INIT  04/0900Z 10.6N 171.4W   25 KT  30 MPH

 12H  04/1800Z 10.8N 172.1W   25 KT  30 MPH...POST-TROP/REMNT LOW

 24H  05/0600Z 11.1N 173.4W   25 KT  30 MPH...POST-TROP/REMNT LOW

 36H  05/1800Z 11.6N 175.2W   25 KT  30 MPH...POST-TROP/REMNT LOW

 48H  06/0600Z 12.3N 177.3W   25 KT  30 MPH...POST-TROP/REMNT LOW

 72H  07/0600Z 13.7N 177.6E   25 KT  30 MPH...POST-TROP/REMNT LOW

 96H  08/0600Z 15.0N 172.0E   25 KT  30 MPH...POST-TROP/REMNT LOW

120H  09/0600Z 16.0N 167.0E   25 KT  30 MPH...POST-TROP/REMNT LOW



$$

FORECASTER JACOBSON