WTPZ45 KNHC 150839 RRA

TCDEP5



HURRICANE DARBY DISCUSSION NUMBER  15

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP052016

200 AM PDT FRI JUL 15 2016



DARBY HAS CHANGED LITTLE IN ORGANIZATION DURING THE PAST SEVERAL

HOURS, WITH SATELLITE IMAGERY SHOWING A RAGGED 25 N MI WIDE EYE

EMBEDDED IN THE CENTRAL DENSE OVERCAST.  SUBJECTIVE SATELLITE

INTENSITY ESTIMATES ARE 90 KT FROM TAFB AND 77 KT FROM SAB, WHILE

VARIOUS OBJECTIVE ESTIMATES FROM CIMSS ARE IN THE 75-80 KT RANGE.

BASED ON THESE DATA, THE INITIAL INTENSITY REMAINS AT 80 KT.



THE INITIAL MOTION IS 280/10.  THERE IS NO CHANGE TO THE FORECAST

PHILOSOPHY FROM THE PREVIOUS ADVISORY, AND THERE ARE NO IMPORTANT

CHANGES TO THE FORECAST TRACK.  THE MODEL GUIDANCE IS IN EXCELLENT

AGREEMENT THAT DARBY WILL MOVE GENERALLY WEST-NORTHWESTWARD FOR THE

NEXT 36-48 HOURS, FOLLOWED BY A MORE WESTWARD MOTION AFTER, AS THE

SUBTROPICAL RIDGE TO THE NORTH OF THE HURRICANE BUILDS SLIGHTLY

SOUTHWARD AND WESTWARD. THE NEW NHC TRACK REMAINS JUST A LITTLE TO

THE SOUTH OF THE CENTER OF THE GUIDANCE ENVELOPE.



SOME STRENGTHENING IS POSSIBLE DURING THE NEXT 12 HOURS WHILE THE

CENTER OF DARBY REMAINS OVER RELATIVELY WARM WATER.  AFTER THAT,

THE FORECAST TRACK TAKES THE CYCLONE OVER DECREASING SEA SURFACE

TEMPERATURES THROUGH 72-96 HOURS, POSSIBLY AS COLD AS 24C.   THIS

SHOULD CAUSE SIGNIFICANT WEAKENING DESPITE AN OTHERWISE FAVORABLE

SHEAR ENVIRONMENT.  IT IS POSSIBLE THAT DARBY COULD WEAKEN MORE THAN

CURRENTLY FORECAST, AS IT APPEARS THAT THE SEA SURFACE TEMPERATURES

NEAR 130W ARE COLDER THAN THOSE USED BY THE SHIPS MODEL.  AFTER 96

HOURS, THE FORECAST TRACK TAKES THE CYCLONE OVER SEA SURFACE=