ZCZC MIATCPAT2 ALL
TTAA00 KNHC DDHHMM
Tropical Storm Grace Intermediate Advisory Number 16A
NWS National Hurricane Center Miami FL AL072021
800 AM EDT Tue Aug 17 2021
...GRACE NEARING JAMAICA...
...HEAVY RAINS CAUSING FLOODING ACROSS PORTIONS OF HISPANIOLA...
SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION
ABOUT 120 MI...195 KM E OF MONTEGO BAY JAMAICA
ABOUT 340 MI...550 KM ESE OF GRAND CAYMAN
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
The government of Jamaica has changed the Tropical Storm Watch for
Jamaica to a Tropical Storm Warning for Jamaica.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Hurricane Watch is in effect for...
* Yucatan Peninsula of Mexico from Cabo Catoche to Punta Allen
A Tropical Storm Warning is in effect for...
* Southern coast of the Cuban provinces of Santiago de Cuba, Granma,
Las Tunas, and Camaguey
* Cayman Islands
A Tropical Storm Watch is in effect for...
* Entire coast of Haiti
* Southern coast of the Cuban provinces of Ciego de Avila, Sancti
Spiritus, Cienfuegos, Matanzas, and Pinar del Rio, as well as Isla
de la Juventud.
A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.
Interests elsewhere in the Yucatan Peninsula of Mexico should
monitor the progress of Grace. Additional watches or warnings may
be required for portions of the Yucatan coast later today.
For storm information specific to your area, please monitor
products issued by your national meteorological service.
DISCUSSION AND OUTLOOK
At 800 AM EDT (1200 UTC), the center of Tropical Storm Grace was
located near latitude 18.2 North, longitude 76.1 West. Grace is
moving toward the west near 16 mph (26 km/h). A general westward to
west-northwestward motion is expected for the next several days. On
the forecast track, the center of Grace will move near or over
Jamaica today. Grace is forecast to move near the Cayman Islands
tonight, and then approach the Yucatan peninsula of Mexico late
Wednesday or early Thursday.
Reports from an Air Force Hurricane Hunter aircraft indicate
that the maximum sustained winds are near 45 mph (75 km/h) with
higher gusts. Gradual strengthening is forecast during the next
couple of days, and Grace could be near hurricane strength when it
approaches the Yucatan coast of Mexico late Wednesday and early
Tropical-storm-force winds extend outward up to 45 miles (75 km)
from the center.
The estimated minimum central pressure is 1005 mb (29.68 inches).
HAZARDS AFFECTING LAND
Key messages for Grace can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC
and on the web at
WIND: Tropical storm conditions are expected in portions of Jamaica
today. Tropical storm conditions are possible in Haiti early this
morning. Tropical storm conditions are expected along the southern
coast of Cuba within the warning area this afternoon and evening,
and over the Cayman Islands beginning tonight into early Wednesday.
Tropical storm conditions are possible along the southern coast of
Cuba within the watch area tonight and Wednesday.
Grace is expected to produce the following rainfall amounts:
Over Haiti...5 to 10 inches of rain with isolated maximum totals of
15 inches are expected across the southern terrain areas today. This
heavy rainfall should lead to flash and urban flooding, and possible
Over far southern Cuba, Jamaica, the Cayman Islands, and portions of
the Yucatan Peninsula....3 to 6 inches of rain with isolated maximum
totals of 9 inches are expected through Thursday. This heavy
rainfall may lead to flash and urban flooding.
SURF: Swells generated by Grace will continue to affect portions of
Hispaniola over the next day or so, and will spread westward to
Jamaica, the Cayman Islands, the southern coast of Cuba, and the
Yucatan Peninsula of Mexico. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office.
Next complete advisory at 1100 AM EDT.