WTPA41 PHFO 032101 RRA

TCDCP1



HURRICANE WALAKA DISCUSSION NUMBER  17

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP012018

1100 AM HST WED OCT 03 2018



SATELLITE IMAGERY SHOWS WALAKA APPARENTLY FEELING THE EFFECTS OF

INCREASING VERTICAL WIND SHEAR.  THE DEEP CONVECTION ON

THE WEST AND SOUTHWESTERN EYEWALL HAS NARROWED, AND THE UPPER LEVEL

CIRRUS OUTFLOW IS BEING ERODED TO THE SOUTHWEST AND ELONGATING OFF

TO THE NORTHEAST. THE CURRENT INTENSITY IS HELD AT 120 KT FOR THIS

ADVISORY BASED ON A BLEND OF THE LATEST SUBJECTIVE DVORAK ESTIMATES

AND THE ADT FROM UW-CIMSS. THESE RANGE FROM 5.5/102 KT FROM SAB TO

7.0/140 KT FROM JTWC TO 6.6/130 KT FROM THE ADT.



WALAKA HAS CONTINUED ACCELERATING TOWARD THE NORTH-NORTHEAST

THIS MORNING, AND THE INITIAL MOTION FOR THIS ADVISORY IS 020/19

KT. WALAKA IS EXPECTED TO CONTINUE ACCELERATING A BIT MORE TOWARD

THE NORTH-NORTHEAST INTO TONIGHT AS IT REMAINS UNDER THE INFLUENCE

OF STEERING FLOW AROUND A DEEP LOW PRESSURE SYSTEM TO THE NORTH.

ONCE THE HURRICANE GETS CLOSER TO THIS EXTRATROPICAL LOW PRESSURE

FEATURE, IT IS EXPECTED TO SLOW CONSIDERABLY. THERE IS GOOD

AGREEMENT IN THIS SCENARIO, WITH ONLY MINOR NORTHWARD CHANGES IN THE

TRACK THROUGH FRIDAY, DUE TO FASTER MOTION IN THE SHORT TERM.

BEYOND FRIDAY, WALAKA GETS PICKED UP BY A TROUGH MOVING ALONG IN

THE WESTERLIES AND ACCELERATES OFF TO THE NORTHEAST, BECOMING

EXTRATROPICAL BY SUNDAY.



RAPID WEAKENING IS FORECAST TONIGHT AND THURSDAY AS CONTINUED

VERTICAL WIND SHEAR VALUES OF UP TO 35 KT COMBINE WITH SST DROPPING

BELOW 27 DEGREES C.  LATER ON THURSDAY, THE VERTICAL WIND SHEAR

RELAXES, BUT CONTINUED WEAKENING IS EXPECTED DUE TO COOLER SSTS.  AS