WTPA41 PHFO 040918 RRA

TCDCP1



HURRICANE WALAKA DISCUSSION NUMBER  19

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP012018

1100 PM HST WED OCT 03 2018



WALAKA'S APPEARANCE HAS CONTINUED TO DEGRADE THIS EVENING, WITH NO

SIGNS OF AN EYE. STRONG VERTICAL WIND SHEAR IS LIKELY TO BLAME FOR

THIS. FORTUNATELY, A PLETHORA OF MICROWAVE IMAGES WERE AVAILABLE

FROM THE FNMOC AND NRL WEB SITES EARLIER THIS EVENING.  THESE

PASSES, WHICH WERE USEFUL FOR DETERMINING THE LOCATION OF THE

LOW-LEVEL CIRCULATION CENTER (LLCC), INDICATED THE EYEWALL

STRUCTURE APPEARED TO REMAIN SOMEWHAT INTACT, ALTHOUGH THERE HAS

BEEN SOME DEGRADATION IN THE SOUTHEASTERN QUADRANT. AS A RESULT OF

THIS CONTINUED WEAKENING, THE LATEST SUBJECTIVE DVORAK CURRENT

INTENSITY ESTIMATES WERE 5.5/102 KT FROM JTWC AND PHFO, AND 4.5/77

KT FROM SAB. THE LATEST UW-CIMSS ADT ESTIMATE WAS 5.8/110 KT.

THE INITIAL INTENSITY FOR THIS ADVISORY IS 110 KT.



WALAKA'S INITIAL MOTION FOR THIS ADVISORY IS 025/19 KT. THE TRACK

FORECAST GUIDANCE REMAINS TIGHTLY CLUSTERED, BUT IT HAS SHIFTED

SLIGHTLY TO THE LEFT DURING THE 12 TO 36 HOUR TIME PERIODS.

THEREFORE, WE HAVE HAD TO MAKE SOME MINOR ADJUSTMENTS IN THE CURRENT

TRACK FORECAST COMPARED WITH THE PREVIOUS ADVISORY DURING THE 12 TO

48 HOUR TIME PERIODS. THIS IS PRIMARILY DUE TO THE WAY THE MODELS

ARE HANDLING THE MUCH ANTICIPATED INTERACTION WITH A DEEP LAYER LOW

CENTERED NEAR 30N 170W THIS EVENING. SINCE THERE IS A GREAT DEAL OF

UNCERTAINTY ABOUT HOW WARM CORE WALAKA WILL RESPOND TO THE CLOSE

ENCOUNTER WITH THIS BAROCLINIC FEATURE, WE ARE ASSUMING IT WILL

SURVIVE THE EVENT INTACT. SO WITH THIS UNCERTAINTY IN MIND, WE HAVE