Official Discussion issued by the National Hurricane Center

Kirk (AL122018) DATA RELEASED: 9/27/2018 11:00:00 AM UTC

Copy of official data

Tropical Storm Kirk Discussion Number  15
NWS National Hurricane Center Miami FL       AL122018
1100 AM AST Thu Sep 27 2018

Increasing vertical shear is having a notable influence on the
structure of Kirk, as visible satellite imagery shows that the
low-level center of the cyclone is now exposed to the west of the
main area of deep convection.  Nonetheless, the Air Force Hurricane
Hunters still found strong winds in that convection.  In fact, based
on SFMR and flight-level winds from the Hurricane Hunters, the
advisory intensity of 45 kt may be a conservative estimate.  With
the increasing vertical decoupling of the vortex and even stronger
shear associated with upper-level westerlies over the Caribbean
Sea, weakening is likely over the next couple of days.  Kirk should
degenerate into a remnant low in 2 to 3 days, if not sooner.  The
official forecast is close to the multi-model intensity consensus,
IVCN.

The storm continues moving west-northwestward, with a current
motion estimate of 285/13 kt.  A mid-level high pressure area just
to the east of Florida is likely to steer Kirk on a
west-northwestward to westward course for the next few days.  Some
further slowing of forward speed is expected as the high weakens
slightly.  The NHC track forecast is very close to the latest HFIP
corrected consensus prediction.

Interests in the Lesser Antilles should bear in mind that, although
Kirk is becoming disorganized, strong winds are still occurring
over the eastern portion of the circulation.  These winds are still
likely to spread westward over the islands in the Tropical Storm
Warning area later today.  Higher winds are especially likely over
elevated terrain.

FORECAST POSITIONS AND MAX WINDS

INIT  27/1500Z 13.8N  59.3W   45 KT  50 MPH
12H  28/0000Z 14.3N  61.0W   40 KT  45 MPH
24H  28/1200Z 14.9N  63.2W   35 KT  40 MPH
36H  29/0000Z 15.5N  65.4W   30 KT  35 MPH
48H  29/1200Z 15.9N  67.7W   25 KT  30 MPH
72H  30/1200Z 16.0N  72.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
96H  01/1200Z...DISSIPATED

$$
Forecaster Pasch