WTPZ41 KNHC 060251 RRA

TCDEP1



TROPICAL STORM ILEANA DISCUSSION NUMBER   6

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP112018

1000 PM CDT SUN AUG 05 2018



A NEW BURST OF DEEP CONVECTION DEVELOPED NEAR THE LOW-LEVEL CENTER

BEGINNING AROUND 2200 UTC.  A SECOND ASCAT PASS EARLIER THIS

AFTERNOON SHOWED WINDS OF 40-45 KT, WHILE SATCON ESTIMATES FROM

UW-CIMSS WERE A LITTLE ABOVE 50 KT.  GIVEN THESE DATA, ILEANA'S

MAXIMUM WINDS ARE ESTIMATED TO BE 45 KT.  THE SHEAR IS FORECAST TO

BE ON THE ORDER OF 15 KT, WHICH IS NOT THE MOST IDEAL ENVIRONMENT

FOR STRENGTHENING, BUT THE CYCLONE WILL ALSO BE MOVING OVER VERY

WARM WATERS OF 30-31 DEGREES CELSIUS AND THROUGH A MOISTURE-LADEN

ENVIRONMENT. NEARLY ALL OF THE INTENSITY MODELS INDICATE ADDITIONAL

STRENGTHENING, WITH SOME, SUCH AS THE SHIPS AND LGEM MODELS,

BRINGING ILEANA NEAR OR TO HURRICANE STRENGTH IN A DAY OR SO.  ON

THE FLIP SIDE, THE GFS AND ECMWF HAVE ILEANA OPENING UP INTO A

TROUGH ON THE NORTHERN SIDE OF TROPICAL STORM JOHN IN 36-48 HOURS.

GIVEN THE LARGE SPREAD IN MODEL SCENARIOS, THE UPDATED NHC INTENSITY

FORECAST IS INCREASED ONLY A LITTLE FROM THE PREVIOUS ADVISORY.  A

48-HOUR FORECAST IS STILL PROVIDED FOR CONTINUITY, BUT IF THE GFS

AND ECMWF ARE RIGHT, THE CYCLONE COULD DISSIPATE BY THAT TIME.



ILEANA IS MOVING A LITTLE FASTER TOWARD THE WEST-NORTHWEST WITH AN

INITIAL MOTION OF 290/11 KT.  ADDITIONAL ACCELERATION WITH A TURN

TOWARD THE NORTHWEST IS EXPECTED OVER THE NEXT DAY OR SO AS THE

CYCLONE MOVES BETWEEN TROPICAL STORM JOHN AND LARGE-SCALE RIDGING

OVER MEXICO AND THE SOUTHERN UNITED STATES.  THE UPDATED NHC TRACK

FORECAST IS ESSENTIALLY RIGHT ALONG THE PROJECTION FROM THE PREVIOUS