WTPZ41 KNHC 181450 RRA

TCDEP1



TROPICAL STORM ESTELLE DISCUSSION NUMBER  13

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP062016

900 AM MDT MON JUL 18 2016



ALTHOUGH THE CLOUD TOPS ARE NOT AS COLD AS THEY WERE YESTERDAY, THE

AREA OF CONVECTION IS A LITTLE MORE SYMMETRIC AROUND THE CENTER

INDICATING THAT THE NORTHWESTERLY SHEAR IS RELAXING.  A COUPLE OF

RECENT MICROWAVE IMAGES ALSO SHOW LESS TILT BETWEEN THE LOW- AND

MID-LEVEL CENTERS, HOWEVER THE INNER CORE IS STILL NOT WELL

ORGANIZED. THE INITIAL WIND SPEED IS MAINTAINED AT 60 KT, WHICH IS

A LITTLE ABOVE THE LATEST DVORAK ESTIMATES.  AN AUTOMATED WEATHER

STATION ON CLARION ISLAND, ABOUT 35 N MI NORTH OF THE CENTER,

RECENTLY REPORTED A SUSTAINED WIND OF 51 KT WITH A GUST TO 71 KT.



THE VERTICAL WIND SHEAR OVER ESTELLE IS FORECAST TO BECOME VERY

LOW LATER TODAY, AND REMAIN LIGHT DURING THE NEXT FEW DAYS.  SINCE

THE TROPICAL STORM IS FORECAST TO REMAIN OVER WARM WATER FOR

ANOTHER 36 HOURS OR SO, MODEST STRENGTHENING IS STILL ANTICIPATED

AND THE NHC FORECAST AND MOST OF THE GUIDANCE STILL CALLS FOR

ESTELLE TO BECOME A HURRICANE WITHIN THE NEXT 24 HOURS.  IN

36 TO 48 H, THE CYCLONE WILL BE MOVING OVER DECREASING SSTS

WHICH SHOULD COMMENCE THE WEAKENING PROCESS.  A FASTER RATE OF

WEAKENING SHOULD BEGIN BY 72 HOURS, WHEN ESTELLE MOVES OVER SSTS

BELOW 24C AND INTO A MORE STABLE AIRMASS.



THE INITIAL MOTION ESTIMATE IS 295/9 KT. ESTELLE SHOULD MOVE

WEST-NORTHWESTWARD TO THE SOUTH OF THE SUBTROPICAL RIDGE DURING THE

NEXT 3 TO 4 DAYS.  AFTER THAT TIME, A WEAKNESS IN THE RIDGE CAUSED

BY A MID- TO UPPER-LOW TO THE NORTHEAST OF THE HAWAIIAN ISLAND

SHOULD CAUSE THE CYCLONE TO TURN NORTHWESTWARD BY DAY 5.  THE TRACK=