ZCZC MIATCPAT4 ALL
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Potential Tropical Cyclone Nine Intermediate Advisory Number 6A
NWS National Hurricane Center Miami FL AL092020
800 PM AST Wed Jul 29 2020
...DISTURBANCE CONTINUES TO BRING HEAVY RAINFALL AND GUSTY WINDS TO
THE U.S. AND BRITISH VIRGIN ISLANDS AND PUERTO RICO...
SUMMARY OF 800 PM AST...0000 UTC...INFORMATION
ABOUT 140 MI...225 KM S OF PONCE PUERTO RICO
ABOUT 280 MI...450 KM SE OF SANTO DOMINGO DOMINICAN REPUBLIC
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
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
* St. Martin and St. Barthelemy
* Saba and St. Eustatius
* St. Maarten
* Dominican Republic entire southern and northern coastlines
* North coast of Haiti from Le Mole St Nicholas eastward to the
northern border with the Dominican Republic
* Turks and Caicos Islands
* Southeastern Bahamas including the Acklins, Crooked Island, Long
Cay, the Inaguas, Mayaguana, and the Ragged Islands
A Tropical Storm Watch is in effect for...
* Central Bahamas, including Cat Island, the Exumas, Long Island,
Rum Cay, and San Salvador
Interests in the northwestern Bahamas and Cuba 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.
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 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 800 PM AST (0000 UTC), the disturbance was centered near latitude
16.0 North, longitude 66.3 West. The system is moving toward the
west-northwest near 18 mph (30 km/h), and this general motion with a
reduction in forward speed is expected over the next few days. On
the forecast track, the system will continue to pass south of Puerto
Rico tonight, near or over Hispaniola on Thursday, near eastern Cuba
and the southeastern Bahamas on Friday, and approach the
northwestern Bahamas and southern Florida Friday night.
Maximum sustained winds are near 45 mph (75 km/h) with higher
gusts. Some increase in strength is forecast through tonight, with
weakening likely on Thursday due to land interaction. Some
restrengthening is possible by this weekend.
Environmental conditions are expected to be conducive for
additional development, and a tropical storm is forecast to form
* Formation chance through 48 hours...high...90 percent
* Formation chance through 5 days...high...90 percent
Tropical-storm-force winds extend outward up to 275 miles (445 km)
primarily to the north of the center.
The estimated minimum central pressure is 1004 mb (29.65 inches).
HAZARDS AFFECTING LAND
Key messages for Potential Tropical Cyclone Nine can be found in
the Tropical Cyclone Discussion under AWIPS header MIATCDAT4, WMO
header WTNT44 KNHC, and on the web at
WIND: Tropical storm conditions will continue across portions of
the Leeward Islands, the U.S. and British Virgin Islands and Puerto
Rico through tonight. These conditions are forecast to reach
portions of the Dominican Republic and Haiti within the warning area
by late tonight or early Thursday, and the southeastern Bahamas and
Turks and Caicos Thursday afternoon. Tropical storm conditions are
possible in the watch area on Friday.
RAINFALL: The disturbance is expected to produce the following
Across the northern Leeward Islands, British and U.S. Virgin
Islands: 3 to 6 inches.
Across Puerto Rico: 3 to 6 inches, with isolated maximum totals of
Across the Dominican Republic, northern Haiti, and Turks and Caicos:
3 to 6 inches, with isolated maximum totals of 8 inches.
Across the Inagua Islands and southeastern Bahamas: 4 to 8 inches.
These rainfall amounts may lead to life-threatening flash flooding
and mudslides, as well as potential riverine flooding beginning
today. Urban and small stream flooding is expected for the U.S.
Virgin Islands and eastern Puerto Rico.
SURF: Swells generated by Potential Tropical Cyclone Nine will be
affecting portions of the Leeward Islands, the Virgin Islands and
Puerto Rico through Thursday. These swells are forecast to
reach the north coast of the Dominican Republic, the Turks and
Caicos Islands and the southeastern Bahamas tonight or Thursday.
These swells are likely to cause life-threatening surf and rip
current conditions. Please consult products from your local
Next complete advisory at 1100 PM AST.