WTPZ45 KNHC 041435 RRA

TCDEP5



TROPICAL STORM IVETTE DISCUSSION NUMBER   8

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP102016

800 AM PDT THU AUG 04 2016



AFTER IVETTE PRODUCED VERY LITTLE CONVECTION NEAR ITS LOW-LEVEL

CENTER LAST EVENING, A LARGE BURST OF THUNDERSTORMS DEVELOPED AROUND

0700 UTC, AND THE CIRRUS CANOPY HAS CONTINUED TO EXPAND SINCE THEN.

HOWEVER, THERE IS NO DATA TO SUPPORT THAT THIS CONVECTION HAS LED TO

ANY INTENSIFICATION YET, AND THE MAXIMUM WINDS REMAIN 40 KT BASED ON

DVORAK CI NUMBERS OF 3.0/45 KT AND 2.5/35 KT FROM TAFB AND SAB,

RESPECTIVELY.



VERTICAL SHEAR APPEARS TO HAVE DECREASED BELOW 10 KT, WHICH MAY BE

FOSTERING THE RECENT INCREASE IN CONVECTION.  WITH SEA SURFACE

TEMPERATURES REMAINING BETWEEN 27-28C AND SHEAR EXPECTED TO BE LOW

DURING THE NEXT THREE DAYS OR SO, INTENSIFICATION IS STILL

ANTICIPATED.  BUT BECAUSE IVETTE HAS FAILED TO STRENGTHEN DURING THE

PAST 24 HOURS, THE PEAK WINDS SHOWN BY THE INTENSITY MODELS CONTINUE

TO DECREASE, AND NONE OF THE GUIDANCE MAKES THE CYCLONE A HURRICANE.

FOR NOW, THE NHC OFFICIAL FORECAST CONTINUES TO SHOW IVETTE REACHING

HURRICANE INTENSITY IN 2-3 DAYS, BUT THIS FORECAST MAY NEED TO BE

ADJUSTED IF IVETTE DOES NOT START STRENGTHENING SOON.  A SIGNIFICANT

INCREASE IN SHEAR AND MARGINAL SSTS SHOULD LEAD TO FAIRLY QUICK

WEAKENING ON DAYS 4 AND 5.



IVETTE IS MOVING WESTWARD, OR 280/13 KT.  A STRONG SUBTROPICAL HIGH

LOCATED NORTH OF THE CYCLONE IS EXPECTED TO STEER IVETTE WESTWARD

FOR THE NEXT 36 HOURS.  AFTER THAT TIME, A BREAK IN THE RIDGE

NORTHEAST OF HAWAII SHOULD CAUSE THE STORM TO SLOW DOWN AND MOVE

WEST-NORTHWESTWARD THROUGH THE END OF THE FORECAST PERIOD.  AGAIN=