WTPZ45 KNHC 060300 RRA

TCDEP5



TROPICAL STORM IVETTE DISCUSSION NUMBER  14

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP102016

800 PM PDT FRI AUG 05 2016



THE CONVECTIVE STRUCTURE OF IVETTE HAS NOT CHANGED SUBSTANTIALLY

THIS EVENING WITH MOST OF THE CONVECTION LIMITED TO THE NORTHEASTERN

SEMICIRCLE.  A BLEND OF THE TAFB/SAB DVORAK, CIMSS ADVANCED DVORAK,

AND AMSU INTENSITY ESTIMATES INDICATE ABOUT 50 KT AT THE INITIAL

TIME, UNCHANGED FROM THE PREVIOUS ADVISORY.  IVETTE REMAINS SMALL IN

SIZE, AS INDICATED BY THE LIMITED CENTRAL DENSE OVERCAST AND

TROPICAL-STORM-FORCE WIND RADII FROM CIRA/AMSU.



WHILE IVETTE REMAINS OVER 28C WATER, THE VERTICAL SHEAR APPEARS TO

STILL BE DISRUPTING THE CONVECTION, AS THE CENTER - LIKE YESTERDAY -

IS OCCASIONALLY SHOWING UP JUST WEST OF THE CIRRUS CANOPY. EVEN

THOUGH THE SHEAR IS QUITE LOW (5 TO 10 KT FROM THE CIMSS AND SHIPS

ANALYSES), IVETTE'S SMALL SIZE AND MODERATE INTENSITY ISN'T ENOUGH

TO OVERCOME THE SHEAR'S DETRIMENTAL EFFECTS.  THE TROPICAL STORM HAS

ABOUT 12-24 HOURS OF TIME LEFT TO INTENSIFY BEFORE THE COMBINATION

OF COOL SSTS, DRY STABLE AIR, AND STRONG SOUTHWESTERLY VERTICAL

SHEAR KICKS IN.  ONCE THAT COMBINATION BEGINS, IVETTE SHOULD

STEADILY WEAKEN AND BECOME A REMNANT LOW IN ABOUT FOUR DAYS AND

DISSIPATE SHORTLY AFTERWARDS.  THE NHC INTENSITY FORECAST, BASED

UPON THE IVCN INTENSITY CONSENSUS TECHNIQUE, INDICATES A SLIGHT

INTENSIFICATION SHORTLY BEFORE WEAKENING COMMENCES IN A COUPLE DAYS.

 IT IS OF NOTE THAT THE ONLY MODEL TO SHOW SIGNIFICANT STRENGTHENING

- COAMPS, BOOSTING IVETTE TO ABOUT 60 KT - HAS BEEN THE BEST

PERFORMING GUIDANCE DURING THE CYCLONE'S LIFETIME.=