WTPA45 PHFO 200900

TCDCP5



TROPICAL DEPRESSION FIVE-C DISCUSSION NUMBER   6

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP052015

1100 PM HST SAT SEP 19 2015



THE LAST FEW VISIBLE SATELLITE IMAGES OF THE DAY...ALONG WITH

SUBSEQUENT 11-3.9 MICRON FOG PRODUCT IMAGERY...INDICATE THAT THE

DEPRESSION CONTINUES TO PRESENT A PARTIALLY EXPOSED CENTER DISPLACED

TO THE WEST OF THE DEEP CONVECTION. STRONG WEST-SOUTHWESTERLY

VERTICAL WIND SHEAR CONTINUES TO IMPACT THE SYSTEM...WITH GOES

UPPER-LEVEL SATELLITE WIND RETRIEVALS AND THE LATEST SHIPS/UW-CIMSS

SHEAR ESTIMATES ALL INDICATING SHEAR MAGNITUDES AROUND 25 KT.

SUBJECTIVE DVORAK CURRENT INTENSITY ESTIMATES CAME IN AT 2.0/30 KT

FROM ALL THREE AGENCIES...WHILE THE LATEST UW-CIMSS ADT INTENSITY

ESTIMATE IS 1.7/27 KT. THE INITIAL INTENSITY WILL BE HELD AT 30 KT

FOR THIS ADVISORY.



WITH THE LAST VISIBLE IMAGES CONTINUING TO INDICATE THE POSSIBILITY

OF MULTIPLE TRANSIENT LOW-LEVEL VORTICES ROTATING AROUND THE MEAN

LOW-LEVEL CIRCULATION CENTER...AND RECENT MICROWAVE DATA SUGGESTING

A POORLY ORGANIZED SYSTEM...THE INITIAL MOTION ESTIMATE IS A RATHER

UNCERTAIN 015/08 KT. THE DEPRESSION IS MOVING TOWARD THE NORTH-

NORTHEAST BETWEEN A BROAD AND DEEP TROUGH CENTERED WEST OF THE

INTERNATIONAL DATE LINE AND A LOW TO MID LEVEL RIDGE LOCATED FAR TO

THE NORTHEAST. THE CYCLONE IS EXPECTED TO CONTINUE ON THE SAME

GENERAL TRACK AND SLOWLY GAIN FORWARD SPEED THROUGH SUNDAY AS

INTERACTION WITH THE DEEP TROUGH INCREASES. A TURN TOWARD THE NORTH

AND THEN THE NORTH-NORTHWEST IS EXPECTED MONDAY AND BEYOND...AS THE

SYSTEM BECOMES DRAWN INTO THE DEEP TROUGH. MOST OF THE RELIABLE

DYNAMICAL GUIDANCE REMAINS TIGHTLY CLUSTERED ABOUT THE FORECAST

TRACK DIRECTION THROUGH THE NEXT 48 HOURS...ALTHOUGH THERE REMAIN

SIGNIFICANT DIFFERENCES IN THE SPEED OF MOTION ALONG THIS TRACK. IT

SHOULD BE NOTED THAT THE 00Z ECMWF DEPICTS A MORE WESTERLY AND

SLOWER TRACK THAN DOES MOST OF THE OTHER GUIDANCE. THE NEW OFFICIAL

TRACK IS VERY SIMILAR TO THE PREVIOUS TRACK AND CLOSE TO THE TVCN

CONSENSUS THROUGH 48 HOURS...THEN IS NUDGED A BIT TO THE RIGHT AND

SLOWER...CLOSER TO THE TVCN...AT 72 AND 96 HOURS.



THE INTENSITY FORECAST REMAINS PROBLEMATIC. SHIPS AND GLOBAL

MODEL GUIDANCE INDICATE THAT THE CURRENT SHEAR WILL REMAIN NEAR

THE CURRENT LEVELS FOR ANOTHER 24 HOURS...THEN INCREASE FURTHER

AS THE CYCLONE MOVES CLOSER TO THE DEEP MID-LATITUDE TROUGH.

DESPITE THIS...THE LATEST SHIPS DOES SHOW SOME SLIGHT

INTENSIFICATION BY 24 HOURS...BRINGING THE SYSTEM TO MINIMAL

TROPICAL STORM STRENGTH. THE GFS ALSO DEPICTS SOME MODEST

INTENSIFICATION DURING THE NEXT COUPLE OF DAYS. THE NEW INTENSITY

FORECAST FOLLOWS THE PREVIOUS ONE...BRINGING THE CYCLONE TO 35 KT

AT 24 HOURS AND THEN HOLDING INTENSITY STEADY THEREAFTER. THIS

IS SLIGHTLY LOWER THAN SHIPS AND HWRF...BUT WELL BELOW THE GFDL.



THERE ARE NO CHANGES TO THE EXISTING TROPICAL STORM WATCHES AND

WARNINGS POSTED FOR PORTIONS OF THE PAPAHANAUMOKUAKEA MARINE

NATIONAL MONUMENT. THE LATER PERIODS OF THIS FORECAST UTILIZED

INPUT FROM THE OCEAN PREDICTION CENTER.





FORECAST POSITIONS AND MAX WINDS



INIT  20/0900Z 20.4N 174.1W   30 KT  35 MPH

 12H  20/1800Z 22.0N 173.6W   30 KT  35 MPH

 24H  21/0600Z 24.6N 172.7W   35 KT  40 MPH

 36H  21/1800Z 27.2N 172.2W   35 KT  40 MPH

 48H  22/0600Z 29.6N 172.3W   35 KT  40 MPH

 72H  23/0600Z 34.5N 173.5W   35 KT  40 MPH...POST-TROP/EXTRATROP

 96H  24/0600Z 39.0N 176.0W   35 KT  40 MPH...POST-TROP/EXTRATROP

120H  25/0600Z...DISSIPATED



$$

FORECASTER JACOBSON