WTPA43 PHFO 012058

TCDCP3



HURRICANE IGNACIO DISCUSSION NUMBER  32

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP122015

1100 AM HST TUE SEP 01 2015



DEEP CONVECTION CONTINUES TO SPUTTER AROUND THE NORTHWEST AND NORTH

SIDE OF THE CORE OF IGNACIO IN THE FACE OF ABOUT 25 TO 30 KNOTS OF

SOUTHWESTERLY SHEAR AS ANALYZED BY BOTH UW-CIMSS AND THE 1800 UTC

SPECIAL SOUNDINGS FROM LIHUE AND HILO. SPIRAL RAINBANDS...AS WELL

AS SOME OF THE CORE STRUCTURE OF THE HURRICANE...CAN BE DISCERNED BY

THE MOLOKAI WEATHER RADAR THIS MORNING. THE DVORAK INTENSITY

ESTIMATES WERE A UNANIMOUS 4.0 FROM THE SATELLITE FIX AGENCIES FOR

THIS ADVISORY...SO THE INITIAL INTENSITY WILL BE SET TO 65 KT.



IGNACIO CONTINUES TO BEHAVE ITSELF AS IT PASSES BY THE MAIN HAWAIIAN

ISLANDS NOT FAR TO OUR NORTHEAST. THE INITIAL MOTION REMAINS TOWARD

THE NORTHWEST...310 DEGREES...AT ABOUT 9 KNOTS. THERE IS STILL NO

CHANGE TO THE FORECAST PHILOSOPHY AS IGNACIO IS EXPECTED TO HEAD

TOWARD THE NORTHWEST FOR THE NEXT 2 DAYS TOWARD A WEAKNESS IN A

MID-LEVEL RIDGE TO THE NORTH OF FRENCH FRIGATE SHOALS. A TURN MORE

TOWARD THE NORTH IS EXPECTED ON DAY 3 AS THE TROPICAL CYCLONE HEADS

FOR THE MID-LATITUDES AND GETS ABSORBED BY A LONGWAVE TROUGH.



THE INTENSITY FORECAST IS QUITE CHALLENGING. IF IGNACIO CAN MAINTAIN

ENOUGH DEEP CONVECTION TO STILL BE CLASSIFIABLE AS A TROPICAL

CYCLONE THROUGH THE NEXT 36-48 HOURS...THE SHEAR WILL RELAX AND THE

CORE WILL STILL BE OVER SEA SURFACE TEMPERATURES JUST OVER 27C. OUR

INTENSITY FORECAST SHOWS ONLY A VERY SLOW WEAKENING TREND THROUGH

THE PERIOD...BUT THERE ARE ALTERNATE POSSIBILITIES THAT IGNACIO

EITHER WILL NOT LAST THAT LONG...OR IF IT DOES...IT COULD BRIEFLY

REINTENSIFY. AT DAYS 4 AND 5...THE CYCLONE IS LIKELY TO START

EXPERIENCING EXTRATROPICAL TRANSITION OVER THE COOLER WATERS OF THE

NORTH PACIFIC. THE INTENSITY FORECAST IS SIMILAR TO THE INTENSITY

CONSENSUS GUIDANCE...BUT SLIGHTLY HIGHER AT DAYS 4 AND 5 WHICH

IS MORE IN LINE WITH THE DYNAMICAL MODELS.



THE FORECAST WIND RADII WERE ADJUSTED A BIT BASED ON AN 0744 UTC

ASCAT PASS.





FORECAST POSITIONS AND MAX WINDS



INIT  01/2100Z 23.8N 154.5W   65 KT  75 MPH

 12H  02/0600Z 24.5N 155.9W   65 KT  75 MPH

 24H  02/1800Z 25.8N 157.9W   65 KT  75 MPH

 36H  03/0600Z 27.2N 160.0W   65 KT  75 MPH

 48H  03/1800Z 28.4N 161.9W   60 KT  70 MPH

 72H  04/1800Z 31.7N 164.2W   60 KT  70 MPH

 96H  05/1800Z 35.3N 165.7W   60 KT  70 MPH

120H  06/1800Z 39.3N 167.8W   55 KT  65 MPH



$$

FORECASTER R BALLARD