WTPA41 PHFO 311501

TCDCP1



TROPICAL DEPRESSION NINE-C DISCUSSION NUMBER   3

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP092015

500 AM HST THU DEC 31 2015



TROPICAL DEPRESSION NINE-C...THE SIXTEENTH TROPICAL CYCLONE OF

2015 IN THE NORTH CENTRAL PACIFIC BASIN...CONTINUES TO PROVIDE MANY

CHALLENGES EARLY THIS MORNING. THE PRIMARY PROBLEM REMAINS THE

LOCATION OF THE LOW-LEVEL CIRCULATION CENTER /LLCC/ OF THE

DEPRESSION. NIGHTTIME INFRARED SATELLITE IMAGERY FROM THE HIMAWARI

SATELLITE HAS BEEN USEFUL IN MONITORING THE SHORT-TERM CHANGES IN

THE EXTENSIVE CONVECTIVE CLOUD TOPS NEAR THE APPARENT LLCC.

HOWEVER...EVEN WITH 10-MINUTE INTERVAL HIGH-RESOLUTION SATELLITE

IMAGERY...THE CIRRUS CANOPY OVER THE SYSTEM CONTINUES TO OBSCURE

MOST OF THE LOWER-LEVEL CUMULUS AND TOWERING CUMULUS CLOUDS THAT

MIGHT HELP US TO LOCATE THE LLCC. ONCE AGAIN...ALL OF THE SATELLITE

FIX AGENCIES...PHFO...SAB AND JTWC...PROVIDED POSITION FIXES THAT

ARE IN RELATIVELY CLOSE PROXIMITY. THE MOST RECENT SUBJECTIVE

DVORAK SATELLITE CURRENT INTENSITY ESTIMATES ARE 2.0/30 KT FROM JTWC

AND SAB...WHILE THE PHFO VALUE IS 2.5/35 KT. THE LATEST CIMSS ADT

ESTIMATE IS 2.9/43 KT. THE ENVIRONMENTAL VERTICAL WIND SHEAR IN

THE VICINITY OF NINE-C ACCORDING TO SHIPS IS 23 KT FROM 110 DEGREES.

DUE TO THE UNCERTAINTY IN THE EXACT LOCATION OF THE LLCC IN A HIGHLY

SHEARED ENVIRONMENT...WE WILL MAINTAIN THE INITIAL INTENSITY

ESTIMATE AT 30 KT FOR THIS ADVISORY.



THE INITIAL MOTION ESTIMATE FOR THIS ADVISORY IS AN UNCERTAIN

300/02 KT. AS WITH THE PREVIOUS ADVISORY...FORECAST TRACK GUIDANCE

FOR NINE-C REMAINS UNRELIABLE...IF IT IS AVAILABLE. SINCE THE GFDL

AND HWRF GUIDANCE MOVE NINE-C IN DIFFERENT DIRECTIONS AND THERE IS NO

ECMWF FORECAST AVAILABLE...THE CONSENSUS MODELS WE NORMALLY RELY ON ARE

AMBIGUOUS. NOTE ALSO THAT GFDL AND HWRF DISSIPATE NINE-C IN 2 TO 3 DAYS.

THE GFS ENSEMBLE MEAN FORECAST IS AVAILABLE...SO WE USED THAT TO MODIFY

THE PREVIOUS OFFICIAL FORECAST TRACK. THE LATEST FORECAST TRACK REMAINS

CLOSE TO THE PREVIOUS...BUT THE FORWARD MOTION OF THE SYSTEM HAS BEEN

DECREASED.



NEAR EQUATORIAL SEA SURFACE TEMPERATURES OF AROUND 30 DEGREES C...AS

WELL AS HIGH VALUES OF OCEAN HEAT CONTENT AS DEPICTED ON THE CIRA

WEB SITE...APPEAR TO BE MAJOR FACTORS THAT MIGHT ULTIMATELY KEEP

NINE-C ALIVE. HOWEVER...THE LATEST FORECAST AGAIN INDICATES THE

SYSTEM WILL DEVELOP SLOWLY...IF AT ALL...DUE TO THE STRONG EASTERLY

SHEAR IN THE 20 TO 25 KT RANGE ACCORDING TO THE LATEST SHIPS

GUIDANCE. IF NINE-C AVOIDS DISSIPATION...IT IS FORECAST TO REACH

TROPICAL STORM INTENSITY BY DAY 4 AS IT APPROACHES THE INTERNATIONAL

DATE LINE. NOTE ALSO THAT THIS FORECAST CONTINUES TO DELAY THE

POTENTIAL CROSSING OF NINE-C INTO THE NORTHWEST PACIFIC UNTIL AROUND

DAY 5.



FORECAST POSITIONS AND MAX WINDS



INIT  31/1500Z  2.4N 176.1W   30 KT  35 MPH

 12H  01/0000Z  2.5N 176.2W   30 KT  35 MPH

 24H  01/1200Z  2.7N 176.6W   30 KT  35 MPH

 36H  02/0000Z  2.9N 177.0W   30 KT  35 MPH

 48H  02/1200Z  3.1N 177.4W   30 KT  35 MPH

 72H  03/1200Z  3.5N 178.2W   30 KT  35 MPH

 96H  04/1200Z  3.9N 179.0W   35 KT  40 MPH

120H  05/1200Z  4.3N 180.0E   40 KT  45 MPH



$$

FORECASTER HOUSTON