Official Discussion issued by the National Hurricane Center

Kirk (AL122018) DATA RELEASED: 9/24/2018 5:00:00 AM UTC

Copy of official data

Tropical Depression Kirk Discussion Number   8
NWS National Hurricane Center Miami FL       AL122018
500 AM AST Mon Sep 24 2018

After having a minimal amount of deep convection late yesterday,
Kirk is now producing some thunderstorm activity in fragmented bands
around the estimated center.  However, earlier ASCAT data and low
cloud motion suggest that the circulation resembles a sharp trough
instead of a closed low that is necessary for a tropical cyclone.
Hopefully more visible satellite images and additional scatterometer
data will help better assess the circulation and status of Kirk.
For now, advisories are being maintained on the system, and the
initial intensity is held at 30 kt based on the earlier ASCAT data
and a blend of the Dvorak estimates.

Kirk is moving very quickly to the west at about 21 kt, which is
likely the reason why the system has been struggling.  A continued
westward motion but at a decreasing forward speed is expected during
the next two to three days while the cyclone remains on the south
side of a low- to mid-level ridge.  After that time, a large
deep-layer low pressure system over the central Atlantic should
cause Kirk to gain more latitude.  The NHC track forecast is largely
an update of the previous one, and remains near the southern side of
the guidance envelope near the GFS and ECMWF models.  This forecast
takes Kirk toward the Lesser Antilles in 3 to 4 days and interests
there should monitor the progress of this system.

Although Kirk will be moving over warmer SSTs and remain in
relatively moist conditions, its fast forward speed will likely
limit the system from strengthening significantly during the next
few days, so only a little intensification is predicted.  The global
models show a notable increase in westerly shear when Kirk reaches
the eastern Caribbean Sea in about 4 days, and that should cause
weakening and possibly even dissipation by the end of the forecast
period.  The NHC intensity forecast lies near the lower side of the
guidance envelope, in best agreement with the NOAA HCCA model.


INIT  24/0900Z  9.5N  37.4W   30 KT  35 MPH
12H  24/1800Z  9.9N  40.5W   30 KT  35 MPH
24H  25/0600Z 10.2N  44.6W   35 KT  40 MPH
36H  25/1800Z 10.5N  48.4W   35 KT  40 MPH
48H  26/0600Z 10.9N  51.7W   40 KT  45 MPH
72H  27/0600Z 12.1N  57.1W   40 KT  45 MPH
96H  28/0600Z 13.2N  61.5W   35 KT  40 MPH
120H  29/0600Z 14.0N  66.0W   30 KT  35 MPH

Forecaster Cangialosi