WTPZ44 KNHC 211443 RRA

TCDEP4



HURRICANE WILLA DISCUSSION NUMBER   6

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP242018

900 AM MDT SUN OCT 21 2018



FIRST-LIGHT GOES-16 VISIBLE SATELLITE IMAGERY SHOWS THAT WILLA

CONTINUES TO BECOME BETTER ORGANIZED, WITH A TIGHTLY COILED BAND

OF CONVECTION WRAPPING AROUND THE CENTER.  THERE HAS ALSO BEEN

EVIDENCE OF A SMALL EYE IN RECENT MICROWAVE AND INFRARED SATELLITE

PICTURES.  SUBJECTIVE AND OBJECTIVE SATELLITE INTENSITY ESTIMATES

RANGE FROM 77 KT TO 90 KT, AND THE INITIAL INTENSITY HAS BEEN

INCREASED TO 85 KT FOR THIS ADVISORY.



WILLA IS MOVING NORTHWESTWARD OR 325/6 KT. THE TRACK GUIDANCE

CONTINUES TO INDICATE THAT WILLA WILL MOVE NORTHWESTWARD TODAY,

THEN TURN NORTHWARD ON MONDAY, AND THEN HEAD NORTH-NORTHEASTWARD

ON TUESDAY BETWEEN A DEEP-LAYER RIDGE THAT EXTENDS WESTWARD FROM THE

GULF OF MEXICO AND AN APPROACHING MID-LEVEL TROUGH. THE DYNAMICAL

MODEL GUIDANCE REMAINS IN GOOD OVERALL AGREEMENT ON THIS SCENARIO,

BUT THERE ARE DIFFERENCES IN HOW QUICKLY WILLA WILL ACCELERATE

NORTH-NORTHEASTWARD.  THE UKMET AND ECMWF ARE MUCH SLOWER THAN THE

REMAINDER OF THE DYNAMICAL MODELS, WITH THE GFS AND GFS ENSEMBLE

MEAN THE FASTEST.  THE NHC TRACK FORECAST BRINGS THE CENTER OF THE

WILLA ONSHORE OF THE COAST OF SOUTHWESTERN MEXICO WITHIN 72 H, AND

IT LIES CLOSEST TO THE HFIP CORRECTED CONSENSUS, WHICH IS A LITTLE

FASTER THAN THE OTHER CONSENSUS AIDS.



THE HURRICANE IS EXPECTED TO REMAIN WITHIN LOW VERTICAL WIND SHEAR

AND OVER WARM WATERS OF AROUND 28 DEGREES CELSIUS DURING THE NEXT

DAY OR TWO.  THESE VERY FAVORABLE CONDITIONS ARE EXPECTED TO ALLOW

STEADY TO RAPID STRENGTHENING THROUGH MONDAY NIGHT, AND THE NHC