180 
WTNT42 KNHC 262032
TCDAT2

Tropical Storm Kirk Discussion Number  12
NWS National Hurricane Center Miami FL       AL122018
500 PM AST Wed Sep 26 2018

The storm's cloud pattern now has a more comma-shaped appearance,
with the estimated center near the western edge of the comma head.
Some low-cloud lines are becoming exposed over the western portion
of the circulation, which is suggestive of some increase in
vertical shear.  Based on flight-level and uncontaminated SFMR winds
from the Air Force Hurricane Hunter mission a few hours ago, the
intensity is kept at 50 kt for this advisory.  The dynamical
guidance is in good agreement that the shear will increase
significantly in 18 to 24 hours, and a weakening trend is likely to
commence around that time.  The system is predicted to dissipate
due to the strong shear over the Caribbean Sea in about 5 days, and
several of the reliable global models show this occurring even
sooner.  The official intensity forecast is similar to the latest
multi-model consensus, IVCN, which has been a good performer in the
Atlantic basin so far this year.

Kirk is moving west-northwestward, or 285/16 kt.  A pronounced
mid-level ridge over the southwestern North Atlantic and Florida
should continue to steer Kirk on a west-northwestward to westward
heading through the forecast period.  Based on the latest track
model guidance, the official forecast is somewhat faster than the
previous one and now takes Kirk over the Lesser Antilles in about
24 hours.  On this basis, the arrival of tropical-storm-force winds
in the warning area is a few hours earlier than implied by the
previous advisory.  For specific timing information, please consult
the latest arrival time of tropical-storm-force winds graphic on the
National Hurricane Center website.

FORECAST POSITIONS AND MAX WINDS

INIT  26/2100Z 12.7N  55.7W   50 KT  60 MPH
 12H  27/0600Z 13.5N  57.9W   50 KT  60 MPH
 24H  27/1800Z 14.4N  60.2W   45 KT  50 MPH
 36H  28/0600Z 15.1N  62.5W   40 KT  45 MPH
 48H  28/1800Z 15.7N  65.0W   35 KT  40 MPH
 72H  29/1800Z 16.3N  70.0W   25 KT  30 MPH
 96H  30/1800Z 15.7N  74.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  01/1800Z...DISSIPATED

$$
Forecaster Pasch