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Tropical Storm Kirk Discussion Number 17
NWS National Hurricane Center Miami FL AL122018
1100 PM AST Thu Sep 27 2018
Satellite images, radar data, aircraft data, and surface
observations all indicate that Kirk's center made landfall on St.
Lucia around 0030 UTC. However, that fact is of minimal consequence
since most of the inclement weather is displaced more than 60 n mi
to the east of the center due to continued 30-40 kt of westerly
shear. An Air Force Reserve Hurricane Hunter aircraft has been
investigating Kirk, and SFMR winds within the convection to the east
still appear to support an initial intensity of 45 kt.
Since the shear affecting Kirk is not expected to abate during the
next couple of days, the storm's maximum winds are forecast to
gradually decrease, as is shown by all of the intensity guidance.
In fact, the global models continue to insist that Kirk's
circulation will open up into a trough, possibly within 24-36 hours.
To maintain continuity with the previous forecast, the new NHC
intensity forecast continues to show Kirk weakening to a tropical
depression in 36 hours but then shows dissipation by 48 hours.
Kirk's center has been moving south of due west during the past
6-12 hours, possibly due to some interaction with the mountains of
St. Lucia, and the initial motion estimate is 260/10 kt. Once the
center moves farther from the island, however, it is expected to
resume a west-northwestward motion and increase in speed a bit as
it comes under the influence of stronger ridging to its north. The
NHC official forecast follows the general trend shown by the track
guidance, and at least speed-wise, it is very close to the previous
forecast and the HCCA model. However, given the recent motion of
the center, the new forecast is nudged southward and lies south of
the most reliable track models and consensus aids.
Interests in the Lesser Antilles should continue to bear in mind
that, although Kirk has become less organized over the past 24
hours, heavy rainfall and winds are still occurring over the eastern
portion of the circulation. These winds and rains are still likely
to spread westward over the islands in the Tropical Storm Warning
area through early Friday. Higher winds are especially likely over
FORECAST POSITIONS AND MAX WINDS
INIT 28/0300Z 13.8N 61.4W 45 KT 50 MPH
12H 28/1200Z 14.3N 63.1W 40 KT 45 MPH
24H 29/0000Z 14.9N 65.4W 35 KT 40 MPH
36H 29/1200Z 15.3N 68.0W 30 KT 35 MPH