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BULLETIN
Potential Tropical Cyclone Eighteen Advisory Number   1
NWS National Hurricane Center Miami FL       AL182017
500 PM EDT Fri Oct 27 2017

...TROPICAL STORM WARNINGS ISSUED FOR WESTERN CUBA AND THE
NORTHWESTERN BAHAMAS...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...17.5N 84.5W
ABOUT 305 MI...490 KM SSW OF THE ISLE OF YOUTH
ABOUT 415 MI...670 KM SSW OF HAVANA CUBA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NNW OR 330 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


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

The government of Cuba has issued a Tropical Storm Warning for
the Cuban provinces of Isla de la Juventud, La Habana, Ciudad de la
Habana, Matanzas, Cienfuegos, and Villa Clara.

The government of the Bahamas has issued a Tropical Storm Warning
for the northwestern Bahamas, including the Abacos, Andros Island,
Berry Islands, Bimini, Eleuthera, Grand Bahama Island, and New
Providence.

The government of the Bahamas has issued a Tropical Storm Watch
for the central Bahamas, including Cat Island, the Exumas, Long
Island, Rum Cay, and San Salvador.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Isla de la Juventud, La Habana, Ciudad de la Habana, Matanzas,
Cienfuegos, and Villa Clara
* Northwestern Bahamas

A Tropical Storm Watch is in effect for...
* Central Bahamas

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, in this case within 36 hours.

Interests in the Cayman Islands, South Florida, and the Florida
Keys should monitor the progress of this system.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 500 PM EDT (2100 UTC), the disturbance was centered near latitude
17.5 North, longitude 84.5 West. The system is moving toward the
north-northwest near 6 mph (9 km/h). A faster northward motion is
expected to begin tonight, followed by a faster motion toward the
northeast on Saturday and Sunday. On the forecast track, the system
will move across western Cuba late Saturday and move through the
northwestern Bahamas Saturday night and early Sunday.

Data from an Air Force Reserve Hurricane Hunter aircraft indicate
that maximum sustained winds are near 40 mph (65 km/h) with higher
gusts. Some strengthening is forecast during the next 24 to 36
hours.

Environmental conditions are expected to be conducive for
development, and the system is likely to become a tropical storm
tonight or Saturday.
* Formation chance through 48 hours...high...80 percent
* Formation chance through 5 days...high...80 percent

Tropical-storm-force winds extend outward up to 80 miles (130 km),
mainly to the south of the center.

The estimated minimum central pressure based on data from the
aircraft is 1006 mb (29.71 inches).


HAZARDS AFFECTING LAND
----------------------
RAINFALL:  The system has the potential to produce the following
rainfall totals:

Northern Honduras:  Additional 1 to 3 inches through Friday night.
Cayman Islands, western and central Cuba and northwestern
Bahamas:  4 to 8 inches with maximum totals of 10 inches.

These rainfall amounts may produce life threatening flash floods and
mudslides.

South Florida including the Florida Keys:  3 to 5 inches, isolated
maximum of 8 inches possible.

These rainfall totals may produce flash flooding, especially in
urbanized areas.

WIND:  Tropical storm conditions are expected to first reach the
warning area in Cuba Saturday and the northwestern Bahamas Saturday
night.


NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM EDT.
Next complete advisory at 1100 PM EDT.

$$
Forecaster Brennan

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