Official Discussion issued by the National Hurricane Center

(AL142018) DATA RELEASED: 10/6/2018 4:00:00 PM UTC

Copy of official data

Potential Tropical Cyclone Fourteen Discussion Number   1
NWS National Hurricane Center Miami FL       AL142018
400 PM CDT Sat Oct 06 2018

Satellite imagery and surface observations indicate that the
circulation of the low pressure area in the northwestern Caribbean
Sea is getting better defined, and that the associated convection
is becoming better organized.  While the system is currently not
well enough organized to call it a tropical depression, current
indications in the global models and the intensity guidance are that
the system will develop into a tropical cyclone within 24 h and
could bring tropical storm conditions to portions of western Cuba
and the northeastern Yucatan Peninsula.  Based on the need for
warnings and watches in these areas, advisories are being initiated
on Potential Tropical Cyclone Fourteen.

Although the intensity guidance is in excellent agreement that the
system should strengthen through the forecast period, the global
models indicate that shear caused by an upper-level trough over the
Gulf of Mexico will persist through at least 48 h.  In addition, the
strongest winds are currently well removed from the center, which is
likely to slow development.  Based on this, the intensity forecast
is in the lower part of the guidance envelope through 48 h, and then
shows a faster rate of development from 48-96 h when the shear is
forecast to diminish.  The intensity forecast is closest to a blend
of the IVCN and HCCA consensus models.

For the first 24-48 h, the disturbance should move generally
northward on the western side of a weak mid-level ridge over the
Caribbean Sea.  After that time, a large mid-latitude trough over
the central United States and a mid- to upper-level ridge over the
western Atlantic should steer the system generally northward at a
faster forward speed, with the system expected to move near or over
the northern Gulf coast in about 96 h.  After landfall, the system
is likely to recurve northeastward into the westerlies.  The track
guidance is in good overall agreement with this scenario.  However,
it should be noted that there is a nearly 300 n mi cross-track
spread in the guidance at the 96-h point.  The forecast track lies
just to the west of the various consensus models.

Key Messages for Potential Tropical Cyclone Fourteen:

1.  This system is expected to produce heavy rainfall and flash
flooding over portions of Central America, western Cuba, and the
northeastern Yucatan Peninsula of Mexico during the next couple of
days.  The system is also forecast to become a tropical storm by
Sunday night and tropical storm conditions are expected over
portions of western Cuba where a Tropical Storm Warning is in
effect.

2. The system could bring storm surge, rainfall, and wind impacts to
portions of the northern Gulf Coast by mid-week, although it is too
soon to specify the exact location and magnitude of these impacts.
Residents in these areas should monitor the progress of this system.

FORECAST POSITIONS AND MAX WINDS

INIT  06/2100Z 18.0N  86.6W   25 KT  30 MPH...POTENTIAL TROP CYCLONE
12H  07/0600Z 18.7N  86.7W   25 KT  30 MPH
24H  07/1800Z 19.9N  86.6W   30 KT  35 MPH...TROPICAL CYCLONE
36H  08/0600Z 21.0N  86.6W   35 KT  40 MPH
48H  08/1800Z 22.5N  86.7W   40 KT  45 MPH
72H  09/1800Z 26.0N  87.5W   55 KT  65 MPH
96H  10/1800Z 30.5N  86.5W   60 KT  70 MPH
120H  11/1800Z 35.5N  81.5W   30 KT  35 MPH...INLAND

$$
Forecaster Beven