WTPZ45 KNHC 140853 RRA

TCDEP5



HURRICANE DARBY DISCUSSION NUMBER  11

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP052016

200 AM PDT THU JUL 14 2016



DARBY CONTINUES TO GENERATE A LARGE AREA OF COLD CLOUD TOPS NEAR

THE CENTER, AND RECENT MICROWAVE IMAGES SHOW A MID-LEVEL EYE IS

PRESENT.  HOWEVER, THE IMAGES ALSO SUGGEST THIS FEATURE IS DISPLACED

TO THE SOUTH OR SOUTHWEST OF THE LOW-LEVEL CENTER, POSSIBLY DUE TO

THE EFFECTS OF NORTHEASTERLY VERTICAL WIND SHEAR. SATELLITE

INTENSITY ESTIMATES FROM TAFB AND SAB REMAIN UNCHANGED AT 65 KT, AND

EARLIER AMSU INTENSITY ESTIMATES WERE NEAR 70 KT.  SO, THE INITIAL

INTENSITY REMAINS 70 KT.



THE INITIAL MOTION IS 275/10.  THE DYNAMICAL MODELS FORECAST A

LARGE DEEP-LAYER RIDGE OVER MUCH OF THE EASTERN AND CENTRAL PACIFIC

FOR THE NEXT SEVERAL DAYS, AND THIS FEATURE SHOULD STEER DARBY

GENERALLY WESTWARD THROUGH THE FORECAST PERIOD.  THE TRACK GUIDANCE

HAS SIMILAR TRACKS TO THAT OF THE PREVIOUS ADVISORY, BUT IT SHOWS

A SLIGHTLY FASTER FORWARD SPEED.  THUS, THE NEW FORECAST TRACK,

WHICH IS A BLEND OF THE GFS AND ECMWF FORECASTS, IS SIMILAR TO, BUT

A LITTLE FASTER THAN, THE PREVIOUS TRACK.



THE CURRENT SHEAR SHOULD SUBSIDE IN THE NEXT 12 HOURS OR SO, WITH

DARBY LIKELY TO REMAIN IN A LIGHT SHEAR ENVIRONMENT DURING THE

REMAINDER OF THE FORECAST PERIOD.  THEREFORE, SEA SURFACE

TEMPERATURE IS EXPECTED TO BE THE MAJOR FACTOR CONTROLLING DARBY'S

INTENSITY.  THE HURRICANE IS CURRENTLY OVER SEA SURFACE TEMPERATURES

NEAR 27C, AND THIS SHOULD CONTINUE FOR THE NEXT 36 HOURS OR SO.

DURING THIS TIME, THE INTENSITY FORECAST CALLS FOR SLOW

STRENGTHENING.  FROM 48-72 HOURS, THE FORECAST TRACK TAKES DARBY=