WTPZ41 KNHC 171440 RRA

TCDEP1



HURRICANE FERNANDA DISCUSSION NUMBER  23

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP062017

800 AM PDT MON JUL 17 2017



FERNANDA'S EYE HAS - ONCE AGAIN - BECOME CLEAR IN THE SHORTWAVE

INFRARED IMAGERY WITH A SLIGHTLY ASYMMETRIC RING OF VERY COLD CLOUD

TOPS SURROUNDING THE 15 NM EYE.  A BLEND OF THE SUBJECTIVE DVORAK

FIXES FROM SAB/TAFB ALONG WITH THE OBJECTIVE ADVANCED DVORAK

TECHNIQUE GIVES 110 KT INTENSITY, MAINTAINING FERNANDA AS A CATEGORY

3 HURRICANE.



IN THE SHORT TERM, THE SSTS BENEATH FERNANDA WILL GRADUALLY COOL,

REACHING 26C IN ABOUT 36 HOURS.  BY DAYS 4 AND 5, THE VERTICAL SHEAR

SHOULD GO UP SUBSTANTIALLY DUE TO FERNANDA MOVING CLOSER TO A

TROPICAL UPPER-TROPOSPHERIC TROUGH.  THUS THE OFFICIAL INTENSITY

FORECAST SHOWS STEADY WEAKENING WITH THE SYSTEM BECOMING A REMNANT

LOW AROUND DAY 5.  THIS FORECAST IS CLOSEST TO A BLEND OF THE LGEM

AND D-SHIPS STATISTICAL INTENSITY SCHEMES, AS WELL AS THE HCCA

CORRECTED CONSENSUS TECHNIQUE.  (THE HWRF AND COAMPS DYNAMICAL

MODELS APPEAR TO HOLD ON TO TOO STRONG A SYSTEM AT DAYS 3 AND

BEYOND, BASED UPON THE ENVIRONMENT THAT FERNANDA IS EXPECTED TO

ENCOUNTER.)



THE HURRICANE IS TRACKING TOWARD THE WEST-NORTHWEST AT ABOUT 9 KT.

FERNANDA IS EXPECTED TO TURN SLIGHTLY TOWARD THE NORTHWEST DURING

THE NEXT COUPLE OF DAYS AS IT MOVES AROUND THE SOUTHWESTERN

PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE.  BY DAYS 3 TO 5, THE

SYSTEM SHOULD TURN BACK TOWARD THE WEST AS IT GETS ADVECTED ALONG IN

THE LOW-LEVEL FLOW AS A WEAKENING TROPICAL CYCLONE.  THE NHC

FORECAST IS NEARLY UNCHANGED FROM THE PREVIOUS ADVISORY AND IS BASED

UPON THE TVCN MULTI-MODEL CONSENSUS TECHNIQUE.