301 
 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