WTPA42 PHFO 051454

TCDCP2



TROPICAL STORM OHO DISCUSSION NUMBER  10

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP072015

500 AM HST MON OCT 05 2015



A BURST OF DEEP CONVECTION HAS MADE IT VERY DIFFICULT TO DETERMINE

WHERE THE CENTER OF OHO IS BASED ON INFRARED SATELLITE IMAGERY EARLY

THIS MORNING. FORTUNATELY...AN AIRCRAFT FROM THE U.S. 53RD WEATHER

RECONNAISSANCE SQUADRON FLEW INTO OHO LAST EVENING...SO WE HAVE SOME

RECENT TRACK...INTENSITY AND WIND RADII INFORMATION TO ASSIST US

WITH INITIALIZING THIS LATEST FORECAST. THE ENVIRONMENTAL VERTICAL

WIND SHEAR IN THE VICINITY OF OHO IS 12 TO 16 KT FROM THE EAST

ACCORDING TO THE LATEST INFORMATION FROM UW/CIMSS AND SHIPS. THE

LATEST SUBJECTIVE DVORAK SATELLITE INTENSITY ESTIMATES WERE 2.5/35

KT FROM PHFO AND SAB...AND 2.0/30 KT FROM JTWC. THE LATEST UW-CIMSS

ADT HAS INCREASED TO 2.7/39 KT. THE INITIAL INTENSITY WILL REMAIN 45

KT BASED ON THE PERSISTENT DEEP CONVECTION IN THE VICINITY OF OHO...

AND THE AIRCRAFT DATA FROM SUNDAY EVENING.



THE INITIAL MOTION ESTIMATE IS 020/02 KT...SINCE OHO REMAINS

IN A WEAK STEERING ENVIRONMENT SOUTH OF A MID-LEVEL RIDGE THAT

EXTENDS FROM THE NORTHEAST PACIFIC OVER THE CENTRAL PACIFIC TO JUST

EAST OF THE BIG ISLAND. THE WESTERN END OF THIS RIDGE IS EXPECTED TO

ERODE LATER TODAY AND TONIGHT AS A DEEP TROUGH DIGS DOWN FROM THE

NORTHWEST TOWARD THE HAWAIIAN ISLANDS. AS THIS RIDGE ERODES...OHO

WILL LIKELY BE STEERED TOWARD THE NORTHEAST DUE TO THE INFLUENCE OF

THE CIRCULATION ASSOCIATED WITH THE TROUGH. TRACK GUIDANCE REMAINS

RATHER TIGHTLY CLUSTERED THROUGH 48 HOURS. HOWEVER...THERE IS A

RATHER LARGE VARIATION IN THE ALONG TRACK GUIDANCE FROM DAYS 3

THROUGH 5. THIS IS LIKELY DUE TO VARIATIONS IN THE WAY THE

INDIVIDUAL MODELS HANDLE THE APPROACHING TROUGH ALOFT. THE LATEST

CONSENSUS TRACK GUIDANCE HAS SHIFTED TO THE RIGHT SLIGHTLY...BUT

THERE HAS BEEN A VERY SIGNIFICANT ACCELERATION TOWARD THE

NORTHEAST...MAINLY DUE TO THE GLOBAL MODELS SUCH AS THE ECMWF AND

GFS. THE LATEST TRACK FORECAST HAS BEEN NUDGED TO THE RIGHT AND

ACCELERATED NORTHEASTWARD BEYOND 24 HOURS TO TRY TO MATCH SOME OF

THE FASTER FORWARD MOTION IN THE MOST RECENT TVCN AND GFEX GUIDANCE.



THE INTENSITY GUIDANCE CONTINUES TO INDICATE THAT OHO WILL REMAIN A

TROPICAL STORM DURING THE NEXT 3 DAYS...WITH THE GLOBAL MODELS

SHOWING A TRANSITION TO AN EXTRATROPICAL SYSTEM BY DAY 4. OHO IS

CURRENTLY OVER SEA SURFACE TEMPERATURES /SST/ OF ABOUT 29C...AND

THE SYSTEM WILL LIKELY REMAIN OVER WARM SST DURING THE NEXT COUPLE

OF DAYS. VERTICAL WIND SHEAR FROM THE SOUTHWEST TO WEST-SOUTHWEST IS

EXPECTED TO INCREASE IN THE VICINITY OF OHO BEYOND 48 HOURS AS THE

DEEP TROUGH DIGS SOUTHEASTWARD TOWARD THE SYSTEM. SOME GRADUAL

INTENSIFICATION IS FORECAST DURING THE NEXT 2 TO 3 DAYS SINCE THE

EASTERLY SHEAR MAY DIMINISH. THE LATEST INTENSITY FORECAST CLOSELY

FOLLOWS THE PREVIOUS ONE...WHICH REMAINS NEAR THE SHIPS AND IVCN

FORECASTS...BUT WEAKER THAN THE HWRF AND GFDL GUIDANCE.



ADDITIONAL AIRCRAFT FROM THE 53RD WEATHER RECONNAISSANCE SQUADRON

ARE SCHEDULED TO FLY INTO OHO LATER THIS MORNING...AND POSSIBLY THIS

EVENING. IN ADDITION...THE NOAA G-IV AIRCRAFT ALSO PLANS TO FLY

ANOTHER SYNOPTIC SAMPLING MISSION AROUND OHO THIS MORNING IN ORDER

FOR THE DATA TO BE UTILIZED IN THE EARLY AFTERNOON MODEL

INITIALIZATION.





FORECAST POSITIONS AND MAX WINDS



INIT  05/1500Z 14.1N 154.6W   45 KT  50 MPH

 12H  06/0000Z 14.6N 154.3W   50 KT  60 MPH

 24H  06/1200Z 15.4N 153.2W   50 KT  60 MPH

 36H  07/0000Z 16.6N 151.4W   55 KT  65 MPH

 48H  07/1200Z 19.2N 149.4W   55 KT  65 MPH

 72H  08/1200Z 26.5N 145.5W   55 KT  65 MPH

 96H  09/1200Z 33.0N 140.0W   40 KT  45 MPH...POST-TROP/EXTRATROP

120H  10/1200Z 40.0N 134.0W   30 KT  35 MPH...POST-TROP/EXTRATROP



$$

FORECASTER HOUSTON