WTPZ41 KNHC 161444 RRA

TCDEP1



HURRICANE FERNANDA DISCUSSION NUMBER  19

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP062017

800 AM PDT SUN JUL 16 2017



IT APPEARS THAT FERNANDA COMPLETED AN EYEWALL REPLACEMENT OVERNIGHT

WITH AN 1109 UTC SSMI MICROWAVE OVERPASS SHOWING EVIDENCE OF A

SINGLE EYEWALL WITH A DIAMETER OF ABOUT 15-20 N MI.  THIS MAY

HAVE LED TO THE RESTRENGTHENING THAT WAS INDICATED IN THE PREVIOUS

ADVISORY.  SINCE THAT TIME, THE EYE HAS REMAINED VERY DISTINCT IN

INFRARED SATELLITE PICTURES BUT THE CONVECTIVE CLOUD TOPS HAVE

WARMED A LITTLE THIS MORNING.  ALTHOUGH DVORAK DATA T-NUMBERS HAVE

DECREASED SLIGHTLY, THE INITIAL INTENSITY REMAINS AT 115 KT, IN

AGREEMENT WITH THE DVORAK CI-NUMBERS FROM TAFB AND SAB.



FERNANDA IS FORECAST TO REMAIN OVER WARM WATER AND WITHIN A LOW

SHEAR ENVIRONMENT DURING THE NEXT 24 HOURS. DURING THAT TIME,

ADDITIONAL EYEWALL REPLACEMENT CYCLES COULD OCCUR LEADING TO SOME

FLUCTUATIONS IN INTENSITY.  SINCE THE TIMING OF EYEWALL REPLACEMENT

CYCLES ARE DIFFICULT TO PREDICT, LITTLE CHANGE IN INTENSITY

IS INDICATED IN THE NHC FORECAST THROUGH MONDAY MORNING.  AFTER THAT

TIME, FERNANDO IS FORECAST TO BEGIN MOVING OVER COOLER WATERS WHICH

SHOULD INITIATE GRADUAL WEAKENING.  THE RATE OF WEAKENING IS

EXPECTED TO INCREASE LATER IN THE PERIOD WHEN FERNANDA MOVES OVER

SSTS OF 25-26C AND WESTERLY SHEAR INCREASES.  THE NHC INTENSITY

FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND IS CLOSE TO THE

VARIOUS CONSENSUS AIDS.



THE HURRICANE IS MOVING WEST-NORTHWESTWARD AT ABOUT 11 KT. THE

TRACK FORECAST REASONING REMAINS UNCHANGED YET AGAIN. FERNANDA IS

EXPECTED TO REMAIN ON A WEST-NORTHWESTWARD HEADING DURING THE NEXT