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Potential Tropical Cyclone Seven Advisory Number 1...Corrected
NWS National Hurricane Center Miami FL AL072021
1100 AM AST Fri Aug 13 2021
Corrected to indicate issuance time of intermediate advisory.
...DISTURBANCE OVER THE CENTRAL TROPICAL ATLANTIC EXPECTED TO
BECOME A TROPICAL STORM BY SATURDAY...
...TROPICAL STORM WATCHES ISSUED FOR A PORTION OF THE LEEWARD
SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
ABOUT 840 MI...1350 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 21 MPH...33 KM/H
MINIMUM CENTRAL PRESSURE...1010 MB...29.83 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
The government of Antigua and Barbuda has issued a Tropical Storm
Watch for Antigua and Barbuda, St. Kitts and Nevis, and Montserrat.
The government of the Netherlands has issued a Tropical Storm Watch
for Saba and Sint Eustatius.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Watch is in effect for...
* Antigua and Barbuda, St. Kitts and Nevis, and Montserrat
* Saba and Sint Eustatius
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.
Interests elsewhere in the Leeward Islands, the Virgin Islands, and
Puerto Rico should monitor the progress of this system. Tropical
Storm Watches will likely be required for these areas later today
For storm information specific to your area, please monitor
products issued by your national meteorological service.
DISCUSSION AND OUTLOOK
At 1100 AM AST (1500 UTC), the disturbance was centered near
latitude 15.3 North, longitude 49.3 West. The system is moving
toward the west near 21 mph (33 km/h), and this general motion with
a gradual decrease in forward speed is expected into early next
week. On the forecast track, the system is expected to approach
the Leeward Islands on Saturday, move over the Leeward Islands
Saturday night and Sunday, and then be near the Virgin Islands and
Puerto Rico Sunday night and Monday.
Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Gradual strengthening is forecast during the next couple of days,
and the disturbance is expected to become a tropical depression
tonight and a tropical storm by Saturday.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...80 percent.
The estimated minimum central pressure is 1010 mb (29.83 inches).
HAZARDS AFFECTING LAND
Key messages for Potential Tropical Cyclone Seven can be found in
the Tropical Cyclone Discussion under AWIPS header MIATCDAT2 and
WMO header WTNT42 KNHC and on the web at
WIND: Tropical storm conditions are possible within the watch
area by Saturday night or early Sunday.
RAINFALL: The system is expected to produce rainfall of 3 to 6
inches across the northern Leeward Islands Saturday into Sunday.
This rainfall may produce scattered areas of flash flooding.
Next intermediate advisory at 200 PM AST.
Next complete advisory at 500 PM AST.