From the 11 AM NHC Advisory
BULLETIN
Potential Tropical Cyclone Nine Advisory Number 1
NWS National Hurricane Center Miami FL AL092020
1100 AM AST Tue Jul 28 2020
...DISTURBANCE FORECAST TO BECOME A TROPICAL STORM BEFORE REACHING
THE LEEWARD ISLANDS...
...TROPICAL STORM WARNINGS ISSUED...
SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...13.8N 53.7W
ABOUT 585 MI...940 KM ESE OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 23 MPH...37 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
A Tropical Storm Warning is in effect for Puerto Rico, including
Vieques, and Culebra, and the U.S. Virgin Islands.
The government of Antigua has issued a Tropical Storm Warning for
Antigua, Barbuda, the British Virgin Islands, Montserrat,
St. Kitts, and Nevis.
The government of France has issued a Tropical Storm Warning for
Guadeloupe, Martinique, and St. Martin.
The government of the Netherlands has issued a Tropical Storm
Warning for Saba and St. Eustatius.
The government of St. Maartin has issued a Tropical Storm Warning
for St. Maartin.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Warning is in effect for...
* Puerto Rico, Vieques, Culebra
* U.S. Virgin Islands
* British Virgin Islands
* Antigua, Barbuda, Montserrat, St. Kitts, and Nevis
* Guadeloupe, Martinique, and St. Martin
* Saba and St. Eustatius
* St. Maartin
Interests elsewhere in the Leeward Islands and Hispaniola should
monitor the progress of this system.
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.
For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area
outside of the United States, please monitor products issued by
your national meteorological service.
DISCUSSION AND OUTLOOK
----------------------
At 1100 AM AST (1500 UTC), the disturbance was centered near
latitude 13.8 North, longitude 53.7 West. The system is moving
toward the west near 23 mph (37 km/h), and this general motion
should continue during the next few days. On the forecast track,
the system is forecast to move through the Leeward Islands on
Wednesday, and near or over the Virgin Islands and Puerto Rico
Wednesday night, and near or over Hispaniola on Thursday.
Maximum sustained winds are near 40 mph (65 km/h) with higher gusts.
Some strengthening is expected during the next 48 hours, and the
system is forecast to become a tropical storm tonight or Wednesday.
Environmental conditions are expected to be conducive for
additional development and a tropical storm tonight or Wednesday.
* Formation chance through 48 hours...high...80 percent
* Formation chance through 5 days...high...90 percent
Tropical-storm-force winds extend outward up to 230 miles (370 km)
primarily to the northeast of the center.
The estimated minimum central pressure is 1007 mb (29.74 inches).
HAZARDS AFFECTING LAND
----------------------
Key messages for Potential Tropical Cyclone Nine can be found in
the Tropical Cyclone Discussion under AWIPS header MIATCDAT4 and
WMO header WTNT44 KNHC.
WIND: Tropical storm conditions are expected to reach the Leeward
Islands on Wednesday and spread into the U.S. and British Virgin
Islands and Puerto Rico Wednesday afternoon through Thursday
morning.
RAINFALL: The potential tropical cyclone will produce total rain
accumulation of 3 to 6 inches with maximum amounts of 10 inches
across the northern Leeward Islands, British and U.S. Virgin
Islands and Puerto Rico. Rainfall accumulations of 2 to 4 inches
possible across the Windward Islands. This rainfall may produce
life threatening flash flooding and mudslides, as well as potential
riverine flooding.
NEXT ADVISORY
-------------
Next intermediate advisory at 200 PM AST.
Next complete advisory at 500 PM AST.
$$
Forecaster Brown
