WTNT44 KNHC 282055 RRA

TCDAT4



TROPICAL DEPRESSION NINE DISCUSSION NUMBER   1

NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092016

500 PM EDT SUN AUG 28 2016



DATA FROM A NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT THE AREA OF

LOW PRESSURE LOCATED IN THE FLORIDA STRAITS NOW HAS A WELL-DEFINED

CENTER.  SATELLITE IMAGERY SHOWS A SIGNIFICANT INCREASE IN THE

CONVECTIVE ORGANIZATION TODAY, AND AS A RESULT THE SYSTEM IS NOW

CLASSIFIED AS A TROPICAL CYCLONE.  THE INITIAL INTENSITY IS SET TO

30 KT BASED ON THE HIGHEST BELIEVABLE WIND DATA FROM THE AIRCRAFT,

WHICH REPORTED A CENTRAL PRESSURE OF 1009 MB.



THE DEPRESSION WILL BE MOVING THROUGH A MARGINAL ENVIRONMENT FOR

INTENSIFICATION DURING THE NEXT DAY OR SO, WITH VERTICAL SHEAR OF

15 TO 20 KT.  AS A RESULT ONLY SLOW STRENGTHENING IS EXPECTED IN

THE SHORT TERM.  LATER ON, THE ENVIRONMENT MAY IMPROVE A LITTLE AS

THE SHEAR IS FORECAST TO DECREASE SOMEWHAT AND BECOME

SOUTHWESTERLY, WHICH SHOULD ALLOW FOR A LITTLE MORE STRENGTHENING.

HOWEVER, THERE ARE MIXED SIGNALS IN THE MODEL GUIDANCE, WITH THE

ECMWF NOW SHOWING THE CYCLONE DISSIPATING IN THE GULF, WHILE THE

GFS DELAYS DEVELOPMENT UNTIL 4-5 DAYS.  MUCH OF THE TROPICAL

CYCLONE GUIDANCE IS MORE AGGRESSIVE.  GIVEN THIS UNCERTAINTY, THE

NHC INTENSITY FORECAST IS QUITE CONSERVATIVE AND SHOWS THE SYSTEM

PEAKING AT 45 KT, BELOW ALL THE EXPLICIT INTENSITY GUIDANCE IN

CONSIDERATION OF THE NEGATIVE SIGNAL FROM THE ECMWF.  NEEDLESS TO

SAY, THE CONFIDENCE IN THE INTENSITY FORECAST IS EVEN LOWER THAN

USUAL FOR THIS SYSTEM.



THE INITIAL MOTION ESTIMATE IS AN UNCERTAIN 270/09 GIVEN THE RECENT

FORMATION OF THE CENTER.  THE CYCLONE WILL BE STEERED IN THE SHORT=