WTPA42 PHFO 050907

TCDCP2



TROPICAL STORM OHO DISCUSSION NUMBER   9

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP072015

1100 PM HST SUN OCT 04 2015



THE FIRST AIRCRAFT FROM THE 53RD WEATHER RECONNAISSANCE SQUADRON

FLEW INTO OHO EARLIER THIS EVENING. THEY FOUND LITTLE MOVEMENT

DURING THEIR TIME IN THE VICINITY OF THE SYSTEM...BUT FLIGHT LEVEL

WINDS WERE NEAR 60 KT AND SFMR WINDS OF NEAR 44 KT. THESE STRONGEST

WINDS WERE PRIMARILY IN THE SOUTH SEMICIRCLE OF OHO. THE SATELLITE

PRESENTATION OF OHO DID NOT SHOW A WELL ORGANIZED TROPICAL CYCLONE

WHILE THE AIRCRAFT WAS FLYING IN IT. THE ENVIRONMENTAL VERTICAL WIND

SHEAR IN THE VICINITY OF OHO WAS ABOUT 15 KT FROM THE EAST ACCORDING

TO THE LATEST INFORMATION FROM SHIPS AND UW/CIMSS. AS A RESULT...

THE LATEST SUBJECTIVE DVORAK SATELLITE INTENSITY ESTIMATES WERE

2.5/35 KT FROM PHFO AND 2.0/30 KT FROM SAB AND JTWC. THE LATEST

UW-CIMSS ADT WAS 2.2...32 KT. DURING THE PAST COUPLE OF HOURS...DEEP

CONVECTION HAS INCREASED NEAR THE CORE OF OHO. THE INITIAL INTENSITY

WILL BE INCREASED TO 45 KT FOR THIS ADVISORY BASED ON THE AIRCRAFT

DATA AND THE IMPROVED SATELLITE PRESENTATION.



AS NOTED ABOVE...THERE HAS BEEN LITTLE SIGNIFICANT MOTION OF

OHO...SO THE INITIAL MOTION ESTIMATE IS 030/01 KT. THE NOAA G-IV

AIRCRAFT SAMPLED PORTIONS OF THE ATMOSPHERE SURROUNDING THE SYSTEM

EARLIER TODAY. THE CURRENT LACK OF SIGNIFICANT MOTION IS LIKELY DUE

TO A MID-LEVEL RIDGE EXTENDING FROM THE NORTHEAST PACIFIC TO THE

CENTRAL PACIFIC NEAR THE BIG ISLAND. A DEEP TROUGH...WHICH IS

CURRENTLY DIGGING DOWN FROM THE NORTHWEST TOWARD THE HAWAIIAN

ISLANDS WILL LIKELY BEGIN TO ERODE THE WESTERN END OF THE RIDGE. AS

RESULT...OHO WILL LIKELY BE STEERED TOWARD THE NORTHEAST. TRACK

GUIDANCE REMAINS RATHER TIGHTLY CLUSTERED. HOWEVER...THERE IS

LARGE VARIATION IN THE ALONG TRACK GUIDANCE...WHICH IS LIKELY DUE

TO VARIATIONS IN THE WAY THE INDIVIDUAL MODELS HANDLE THE

APPROACHING TROUGH. THE LATEST CONSENSUS TRACK GUIDANCE HAS SHIFTED

TO THE RIGHT SLIGHTLY...BUT THERE HAS BEEN A VERY SIGNIFICANT

ACCELERATION...MAINLY DUE TO THE GLOBAL MODELS SUCH AS THE ECMWF

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

RIGHT AND ACCELERATED NORTHEASTWARD SLIGHTLY TO TRY TO MATCH SOME

OF THE FASTER FORWARD MOTION IN THE TVCN AND GFEX GUIDANCE.



THE INTENSITY GUIDANCE CONTINUES TO INDICATE THAT OHO WILL REMAIN A

TROPICAL STORM DURING THE NEXT 4 DAYS...WITH THE GLOBAL MODELS

SHOWING A TRANSITION TO AN EXTRATROPICAL SYSTEM BY DAY 5. OHO IS

CURRENTLY OVER A SEA SURFACE TEMPERATURE /SST/ OF ABOUT 29C.

THE SYSTEM WILL LIKELY REMAIN IN WARM SSTS DURING THE NEXT COUPLE OF

DAYS. VERTICAL WIND SHEAR 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 FORECAST...BUT BELOW GUIDANCE FROM HWRF AND GFDL.



ADDITIONAL AIRCRAFT OPERATIONS INTO OHO WILL BE FLOWN ON MONDAY IF

THE SYSTEM CONTINUES TO POSE A POTENTIAL FUTURE THREAT TO THE

HAWAIIAN ISLANDS. THE NOAA G-IV AIRCRAFT ALSO PLANS TO FLY

ANOTHER SYNOPTIC MISSION AROUND OHO ON MONDAY MORNING...IN ORDER FOR

THE DATA TO BE UTILIZED IN THE MONDAY AFTERNOON MODEL RUNS.





FORECAST POSITIONS AND MAX WINDS



INIT  05/0900Z 13.8N 154.6W   45 KT  50 MPH

 12H  05/1800Z 14.3N 154.2W   50 KT  60 MPH

 24H  06/0600Z 14.9N 153.4W   50 KT  60 MPH

 36H  06/1800Z 15.7N 152.2W   50 KT  60 MPH

 48H  07/0600Z 17.3N 150.4W   55 KT  65 MPH

 72H  08/0600Z 22.5N 147.5W   55 KT  65 MPH

 96H  09/0600Z 29.0N 143.4W   45 KT  50 MPH

120H  10/0600Z 35.5N 137.5W   40 KT  45 MPH...POST-TROP/EXTRATROP



$$

FORECASTER HOUSTON