Tropical Depression Eighteen Discussion Number 4
NWS National Hurricane Center Miami FL AL182024
1000 AM EST Mon Nov 04 2024

Data from the Air Force Hurricane Hunters, satellite images, and
surface observations indicate that the low pressure system over the
south-central Caribbean Sea has developed a well-defined center and
is producing organized deep convection. Therefore, the system now
meets the criteria of a tropical depression. The maximum
flight-level winds from the aircraft support holding the initial
wind speed steady at 30 kt. Deep convection is gradually organizing
near the center and in bands around it, especially on the south and
east sides of the circulation.

The depression has jogged a bit to the right of the previous track,
and the initial motion estimate is now 010/8 kt. A turn to the
northwest is expected later today, and that motion is forecast to
continue during the next few days as a ridge builds over the
southwestern Atlantic and northeastern Caribbean. This motion should
take the center of the system near Jamaica tonight, near or over the
Cayman Islands by late Tuesday, and across western Cuba on
Wednesday. After that time, when the system reaches the Gulf of
Mexico, the model solutions diverge, which appears to be due to
differences in the steering patterns and vertical depth of the
storm. The NHC track forecast is largely an update of the previous
one and remains close to the various consensus models. However, it
should be noted that the track forecast over the Gulf of Mexico is
of low confidence.

The environmental factors of low wind shear, high moisture, and warm
SSTs support intensification, and since the system now has a well
organized circulation, there is increasing confidence of steady
strengthening until the system reaches Cuba or the southeastern Gulf
of Mexico. In 3 or 4 days, when the system reaches the central Gulf,
a sharp increase in southwesterly vertical wind shear, drier air,
and slightly cooler waters should end the strengthening trend and
induce weakening. The NHC intensity forecast lies near the middle of
the guidance envelope, fairly close to the HCCA and IVCN consensus
aids.


Key Messages:

1. Hurricane conditions are expected in the Cayman Islands on
Tuesday and are possible in portions of Cuba early Wednesday, where
Hurricane Warnings and Watches are in effect. There is a risk of
dangerous impacts from hurricane-force winds and storm surge in the
Cayman Islands and portions of western Cuba. Tropical storm
conditions are expected in Jamaica this evening.

2. Interests in the Florida Keys should closely monitor this system
as tropical storm watches could be required for portions of these
areas later today.

3. The system is forecast to enter the Gulf of Mexico later this
week, but given significant uncertainties in the long-range forecast
track and intensity, it is too soon to determine what, if any,
impacts could occur. Residents in this area should regularly monitor
updates to the forecast.

4. The system will bring areas of heavy rain across portions of the
western Caribbean, including Jamaica and portions of Cuba through
mid-week. Flooding and mudslides are possible in these areas. Heavy
rainfall will spread north into Florida and adjacent areas of the
Southeast United States mid to late week.


FORECAST POSITIONS AND MAX WINDS

INIT 04/1500Z 15.2N 76.9W 30 KT 35 MPH
12H 05/0000Z 16.5N 77.6W 35 KT 40 MPH
24H 05/1200Z 18.2N 79.0W 45 KT 50 MPH
36H 06/0000Z 19.9N 80.7W 60 KT 70 MPH
48H 06/1200Z 21.7N 82.4W 70 KT 80 MPH
60H 07/0000Z 23.4N 83.9W 70 KT 80 MPH
72H 07/1200Z 24.6N 85.1W 70 KT 80 MPH
96H 08/1200Z 26.1N 87.4W 65 KT 75 MPH
120H 09/1200Z 27.4N 89.5W 55 KT 65 MPH

$$
Forecaster Cangialosi/Kelly

BULLETIN
Tropical Depression Eighteen Intermediate Advisory Number 4A
NWS National Hurricane Center Miami FL AL182024
100 PM EST Mon Nov 04 2024

...DEPRESSION NEARING TROPICAL STORM STRENGTH...
...TROPICAL STORM CONDITIONS EXPECTED TO BEGIN IN JAMAICA
LATE TONIGHT...


SUMMARY OF 100 PM EST...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...15.1N 76.4W
ABOUT 200 MI...325 KM S OF KINGSTON JAMAICA
ABOUT 430 MI...690 KM SE OF GRAND CAYMAN
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...N OR 10 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Cayman Islands

A Hurricane Watch is in effect for...
* Cuban provinces of Pinar del Rio, Artemisa, La Habana,
Mayabeque, Matanzas, and the Isle of Youth

A Tropical Storm Warning is in effect for...
* Jamaica

A Tropical Storm Watch is in effect for...
* Cuban provinces of Villa Clara, Cienfuegos, Sancti Spiritus, Ciego
de Avila, Camaguey, and Las Tunas

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued 36
hours before the anticipated first occurrence of
tropical-storm-force winds, conditions that make outside
preparations difficult or dangerous. Preparations to protect life
and property should be rushed to completion.system. Additional
watches or warnings could be required today.

A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours before
the anticipated first occurrence of tropical-storm-force winds,
conditions that make outside preparations difficult or dangerous.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, in this case within 24
hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.

Interests elsewhere in Cuba and the Florida Keys should closely
monitor this system.

For storm information specific to your area, please monitor
products issued by your national meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 100 PM EST (1800 UTC), the center of Tropical Depression Eighteen
was located near latitude 15.1 North, longitude 76.4 West. The
depression is moving toward the north near 9 mph (15 km/h). A
northwestward motion is expected to begin later today and forecast
to continue for the next few days. On the forecast track, the system
is expected to move near Jamaica late tonight, be near or over the
Cayman Islands on Tuesday, and approach Cuba on Wednesday.

Maximum sustained winds remain near 35 mph (55 km/h) with higher
gusts. Steady strengthening is forecast, and the depression is
expected to become a tropical storm later today or tonight, and a
hurricane by Wednesday.

The estimated minimum central pressure is 1000 mb (29.53 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Tropical Depression Eighteen can be found in the
Tropical Cyclone Discussion under AWIPS header MIATCDAT3 and WMO
header WTNT43 KNHC and on the web at
hurricanes.gov/text/MIATCDAT3.shtml

WIND: Hurricane conditions are expected in the Cayman Islands by
Tuesday afternoon and are possible in western Cuba and the Isle of
Youth on Wednesday. Tropical storm conditions are expected in
Jamaica by late tonight and are possible in central Cuba on
Wednesday.

RAINFALL: Heavy rainfall will impact areas of the western Caribbean
with the heaviest rainfall occurring over Jamaica and portions of
Cuba through mid-week. Rainfall totals between 3 to 6 inches with
locally up to 9 inches are expected. Flooding could occur over
portions of Jamaica and Cuba, with mudslides possible.

Heavy rainfall will spread north into Florida and adjacent areas of
the Southeast United States during mid- to late week.

For a complete depiction of forecast rainfall associated with
Tropical Depression Eighteen, please see the National Weather
Service Storm Total Rainfall Graphic, available at
www.nhc.noaa.gov/graphics_at3.shtml?rainqpf

STORM SURGE: Minor coastal flooding is possible in Jamaica tonight
and the Cayman Islands on Tuesday. Storm surge could raise water
levels by as much as 2 to 4 feet above normal tide levels in areas
of onshore winds along the southern coast of Pinar del Rio, Cuba,
including the Isle of Youth.

SURF: Swells generated by the system are expected to affect much
of the western Caribbean during the next few days. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 400 PM EST.

$$
Forecaster Cangialosi