NWS National Hurricane Center Miami FL AL152017
1100 AM AST Sat Sep 16 2017
…TROPICAL STORM WATCHES ISSUED FOR A PORTION OF THE LESSER ANTILLES…
SUMMARY OF 1100 AM AST…1500 UTC…INFORMATION
ABOUT 755 MI…1220 KM ESE OF THE LESSER ANTILLES
MAXIMUM SUSTAINED WINDS…35 MPH…55 KM/H
PRESENT MOVEMENT…W OR 280 DEGREES AT 22 MPH…35 KM/H
MINIMUM CENTRAL PRESSURE…1008 MB…29.77 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
The government of St. Lucia has issued a Tropical Storm Watch for St. Lucia.
The government of France has issued a Tropical Storm Watch for Martinique and Guadeloupe.
The government of Barbados has issued a Tropical Storm Watch for Dominica.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Watch is in effect for…
* St. Lucia
A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours.
Interests elsewhere in the Lesser Antilles should monitor the progress of this system. Additional Tropical Storm or Hurricane Watches will likely be issued later today.
For storm information specific to your area, please monitor products issued by your national meteorological service.
DISCUSSION AND 48-HOUR OUTLOOK
At 1100 AM AST (1500 UTC), the disturbance was centered near latitude 12.2 North, longitude 50.5 West. The system is moving toward the west near 22 mph (35 km/h). A slower west-northwest motion is expected during the next couple of days. On the forecast track, the system is expected to approach the Leeward Islands on Monday.
Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Strengthening is expected during the next 48 hours. The disturbance is forecast to become a tropical storm later today and could be near hurricane strength when it approaches the Leeward Islands.
Satellite images indicate that the disturbance has become better organized, and it is expected to become a tropical cyclone later today or tonight.
* Formation chance through 48 hours…high…near 100 percent
* Formation chance through 5 days…high…near 100 percent
The estimated minimum central pressure is 1008 mb (29.77 inches).
HAZARDS AFFECTING LAND
WIND: Hurricane conditions are possible within portions of Leeward Islands by Monday night or Tuesday, with tropical storm conditions possible on Monday.
RAINFALL: The system is expected to produce total rain accumulations of 5 to 10 inches with isolated maximum amounts of 15 inches across portions of the central and southern Leeward Islands through Tuesday night. These rains could cause life-threatening flash floods and mudslides.
SURF: Swells generated by the system are expected to begin affecting the Lesser Antilles by Sunday night. These swells are likely to cause life-threatening surf and rip current conditions.
Source: The Daily Herald https://www.thedailyherald.sx/islands/69420-potential-tropical-cyclone-fifteen-advisory-number-1