WTPA41 PHFO 022105 RRA

TCDCP1



HURRICANE WALAKA DISCUSSION NUMBER  13

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP012018

1100 AM HST TUE OCT 02 2018



MORNING VISIBLE AND INFRARED SATELLITE IMAGERY TRENDS SHOWING WALAKA

HAS DEGRADED SOMEWHAT OVER THE PAST SEVERAL HOURS.  THE EYE HAS

BECOME LESS DISTINCT WITH A CLOUDS APPARENTLY PARTIALLY COVERING THE

EYE. CLOUD TOPS HAVE WARMED IN THE EYEWALL AND SURROUNDING

CONVECTIVE RING, AND DVORAK INTENSITY ESTIMATES STARTED TO FOLLOW

THIS WEAKENING TREND WHICH BEGAN OVERNIGHT. CURRENT INTENSITIES

RANGE FROM 6.0 AT SAB TO 6.5 AT PHFO AND JTWC. HAVE CONSERVATIVELY

LOWERED THE INITIAL INTENSITY TO 130 KT FOR THIS FORECAST CYCLE AS

SATCON ESTIMATES AS OF 1528 UTC WERE AT 132 KNOTS, WITH A VERY SLOW

WEAKENING IN THE SHORT TERM AS WALAKA APPEARS TO BE COMPLETING AN

EYEWALL REPLACEMENT CYCLE BASED ON EARLIER COMPOSITE MICROWAVE DATA

OVERNIGHT. A SOLID ASCAT PASS FROM 0816 UTC WAS USEFUL TO MAKE MINOR

ADJUSTMENTS TO THE WIND RADII, AND AN ALTIMETER PASS AIDED IN

ADJUSTING THE 12 FOOT SEAS RADII.



THE INITIAL MOTION WAS SET AT 355/09 KNOTS, AS WALAKA CONTINUES TO

BE DRAWN NORTHWARD BY THE DEEP LOW PRESSURE SYSTEM TO THE NORTH.

THIS MOTION IS EXPECTED TO CONTINUE OVER THE NEXT DAY OR TWO WITH

SOME ACCELERATION AS THE INFLUENCE OF THIS LOW PRESSURE OVER THE

WALAKA STEERING CURRENTS INCREASES.  BY THURSDAY AND FRIDAY,

WALAKA SLOWS AS IT INTERACTS WITH THE MID LATITUDE TROUGH WHICH

REMAINS CUTOFF FROM THE MID LATITUDE WESTERLIES ALOFT.  BY EARLY

SATURDAY, ANOTHER SHARP UPPER TROUGH PICKS THE TROPICAL CYCLONE UP

AND SHIFTS IT OFF TO THE NORTHEAST THROUGH THE WEEKEND, RESULTING IN