WTPA42 PHFO 032051

TCDCP2



TROPICAL STORM OHO DISCUSSION NUMBER   3

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP072015

1100 AM HST SAT OCT 03 2015



SATELLITE IMAGES SHOWED PERSISTENT DEEP CONVECTION NEAR THE CENTER

OF OHO. CLOUD TOP TEMPERATURES HAVE WARMED A BIT OVER THE PAST FEW

HOURS BUT THERE ARE STILL TOPS COLDER THAN -80C DISPLACED SLIGHTLY

SOUTH OF THE CENTER. THE CENTRAL DENSE OVERCAST OF OHO APPEARS TO BE

SEPARATING FROM A LARGE OUTER RAIN BAND THAT FORMED YESTERDAY

EVENING AND EXTENDED TOWARD THE SOUTH. IT IS ALSO A BIT ASYMMETRIC

WITH BETTER UPPER LEVEL OUTFLOW TO THE NORTHEAST. THIS IS CONSISTENT

WITH THE 13 KT OF SOUTHWESTERLY VERTICAL WIND SHEAR ANALYZED BY

CIMSS AT 1800 UTC. DVORAK INTENSITY ESTIMATES CAME IN AT 2.5/35 KT

FROM PHFO AND JTWC...AND 2.0/30 KT FROM SAB. THE CIMSS ADT ESTIMATE

WAS 43 KT AT 1800 UTC. BASED ON A BLEND OF THESE DATA...THE INITIAL

INTENSITY WILL BE HELD AT 35 KT FOR THIS ADVISORY.



THE INITIAL MOTION FOR THIS PACKAGE IS 350/06 KT. A LONG WAVE TROUGH

TO THE NORTH AND NORTHWEST...AND A RIDGE TO THE EAST IS PROVIDING A

WEAK SOUTHERLY STEERING CURRENT. THE RIDGE IS FORECAST TO BUILD

WESTWARD TONIGHT...WHICH IS EXPECTED TO SHIFT THE STEERING TOWARD

THE NORTHWEST. A NEW SHORT WAVE TROUGH IS PROJECTED TO DEEPEN

THE LONG WAVE TROUGH NORTH OF THE TROPICAL CYCLONE ON

MONDAY...RESULTING IN A SHARP TURN BACK TO THE EAST OR NORTHEAST.

THE MODELS VARY ON THE SHARPNESS AND TIMING OF THE TURN. DESPITE THE

COMPLEXITY OF THE S-SHAPED FORECAST TRACK...THE MODELS ARE QUITE

CONSISTENT WITH THIS PROJECTION AND THE PATHS OF THE TRUSTED GFS AND

ECMWF ARE QUITE CLOSE TO EACH OTHER WITH THE MAIN DIFFERENCE BEING

IN OHO/S FORWARD SPEED. THUS...THE FORECAST FOR THIS ADVISORY IS

MAINLY AN UPDATE OF THE PREVIOUS FORECAST THROUGH 72 HOURS...WHICH

IS CONSERVATIVELY TO THE LEFT OF THE GFS AND ECMWF...THEN NUDGED

TOWARD THE GFS AND ECMWF CONSENSUS AT 96 AND 120 HOURS.



OHO IS MOVING OVER VERY WARM WATER WITHIN A MOIST ENVIRONMENT.

HOWEVER...THE 13 KT OF SOUTHWESTERLY VERTICAL WIND SHEAR MENTIONED

PREVIOUSLY IS A BIT STRONGER THAN EXPECTED AND THIS MAY

HAVE HALTED STRENGTHENING TEMPORARILY. THE SHEAR IS EXPECTED TO EASE

WHICH SHOULD PROVIDE AN OPPORTUNITY FOR OHO TO STRENGTHEN AGAIN. IN

FACT...THE RAPID INTENSIFICATION INDEX INDICATES A 57 PERCENT

PROBABILITY OF 25 KT INCREASE IN 24 HOURS. THE CURRENT FORECAST IS

NOT AS AGGRESSIVE BUT DOES BRING OHO TO 50 KT IN 24 HOURS AND A

MAXIMUM INTENSITY OF 75 KT IN 96 HOURS. THIS PROJECTION IS CLOSE TO

THE INTENSITY CONSENSUS THROUGH THE FORECAST PERIOD.



THE 53RD WEATHER RECONNAISSANCE SQUADRON HAS BEEN TASKED TO FLY THIS

SYSTEM IN SUPPORT OF CPHC OPERATIONS...AND INITIAL FLIGHTS INTO OHO

ARE PLANNED FOR SUNDAY EVENING AND MONDAY MORNING. THE G-IV AIRCRAFT

IS ALSO HEADING TO HAWAII TO FLY SYNOPTIC MISSIONS...WITH HIGH-

ALTITUDE FLIGHTS PLANNED FOR SUNDAY AND MONDAY MORNINGS...IN ORDER

FOR THE DATA TO BE UTILIZED BY AFTERNOON MODEL RUNS.





FORECAST POSITIONS AND MAX WINDS



INIT  03/2100Z 14.6N 154.1W   35 KT  40 MPH

 12H  04/0600Z 14.9N 154.5W   40 KT  45 MPH

 24H  04/1800Z 15.4N 155.1W   50 KT  60 MPH

 36H  05/0600Z 15.8N 155.3W   60 KT  70 MPH

 48H  05/1800Z 16.1N 154.9W   65 KT  75 MPH

 72H  06/1800Z 16.6N 153.7W   70 KT  80 MPH

 96H  07/1800Z 17.5N 151.5W   75 KT  85 MPH

120H  08/1800Z 20.5N 150.0W   60 KT  70 MPH



$$

FORECASTER KODAMA