WTPA42 PHFO 080855

TCDCP2



HURRICANE OHO DISCUSSION NUMBER  21

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP072015

1100 PM HST WED OCT 07 2015



OHO IS BEGINNING EXTRATROPICAL TRANSITION...WITH AN INCREASINGLY

SHEARED SATELLITE PRESENTATION. SHIPS AND UW-CIMSS ANALYSES SHOW 45

TO 50 KT OF SOUTH SOUTHWESTERLY SHEAR...WHILE SHIPS ALSO SHOWS OHO

MOVING ACROSS 23C WATER. THE LOW LEVEL CIRCULATION

CENTER...LLCC...REMAINS EXPOSED...WITH ALL REMAINING DEEP

CONVECTION PUSHED OFF TO THE NORTH NORTHEAST. SUBJECTIVE DVORAK

SATELLITE INTENSITY ESTIMATES WERE 4.0...65 KT...FROM PHFO AND

JTWC...WHILE UW-CIMSS ADT HAS OHO AT 55 KT. OHO IS SPINNING DOWN AS

A TROPICAL SYSTEM...SO SETTING THE INITIAL INTENSITY AT 65 KT FOR

THIS ADVISORY SEEMS REASONABLE.



INITIAL MOTION IS 030/34 KT. OHO HAS BEEN SCOOPED UP BY DEEP

TROUGHING TO ITS NORTHWEST AND IS NOW RACING NORTH NORTHEASTWARD

TOWARD THE MAINLAND. SINCE OHO WILL LIKELY COMPLETE EXTRATROPICAL

TRANSITION WITHIN 12 HOURS...WE COLLABORATED WITH THE OCEAN

PREDICTION CENTER...OPC...FOR ALL POINTS ALONG THE FORECAST TRACK.

OPC KINDLY CONTRIBUTED WIND AND SEAS RADII AS WELL. THE CURRENT

FORECAST TRACK KEEPS OHO HEADED TOWARD BRITISH COLUMBIA THROUGH 24

HOURS...THEN CURVES THE TRACK NORTHWESTWARD AT 36 AND 48 HOURS AS

THIS SYSTEM MOVES ALONG THE NORTHEASTERN FLANK OF A LARGE POLAR LOW

FORMING ACROSS THE ALEUTIANS. AS OHO BECOMES AN EXTRATROPICAL

STORM LOW...ITS WIND FIELD WILL EXPAND AND BECOME HIGHLY ASYMMETRIC.



OHO WILL WEAKEN THROUGH 24 HOURS...SPINNING DOWN AT THE MET RATE

ACCORDING TO CONCEPTUAL MODELS. HOWEVER...BAROCLINIC FORCES WILL

STRENGTHEN THE REMNANTS OF OHO BACK TO HURRICANE STRENGTH AS AN

EXTRATROPICAL STORM LOW BETWEEN 24 AND 36 HOURS. THIS STORM LOW

WILL THEN WEAKEN AGAIN BY 48 HOURS AS IT INTERACTS WITH THE ALASKAN

PANHANDLE...THEN DISSIPATE INLAND BY 72 HOURS.



THE CENTRAL PACIFIC HURRICANE CENTER WILL ISSUE ONE MORE ADVISORY

AFTER THIS ONE TO CLOSE THINGS DOWN WITH OHO PROPERLY. OHO WILL

BECOME EXTRATROPICAL BEFORE CROSSING 140W...SO AFTER THE 1500 UTC

ADVISORY CYCLE IT WILL BECOME THE RESPONSIBILITY OF OPC AND WILL BE

COVERED BY OPC HIGH SEAS FORECASTS.





FORECAST POSITIONS AND MAX WINDS



INIT  08/0900Z 32.5N 143.1W   65 KT  75 MPH...BECOMING EXTRATROPICAL

 12H  08/1800Z 37.0N 140.0W   55 KT  65 MPH...POST-TROP/EXTRATROP

 24H  09/0600Z 47.0N 136.0W   50 KT  60 MPH...POST-TROP/EXTRATROP

 36H  09/1800Z 55.0N 137.0W   75 KT  85 MPH...POST-TROP/EXTRATROP

 48H  10/0600Z 59.0N 140.0W   35 KT  40 MPH...POST-TROP/EXTRATROP

 72H  11/0600Z...DISSIPATED



$$

FORECASTER POWELL