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Tropical Storm Grace Intermediate Advisory Number 15A
NWS National Hurricane Center Miami FL AL072021
200 AM EDT Tue Aug 17 2021
...RECONNAISSANCE AIRCRAFT FINDS GRACE HAS BECOME A TROPICAL
...EXTREME HEAVY RAIN CAUSING FLOODING ACROSS PORTIONS OF
SUMMARY OF 200 AM EDT...0600 UTC...INFORMATION
ABOUT 230 MI...370 KM E OF MONTEGO BAY JAMAICA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
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 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.
Interests in the Yucatan Peninsula of Mexico should monitor the
progress of Grace. Watches may be required for portions of the
Yucatan coast later this morning.
For storm information specific to your area, please monitor
products issued by your national meteorological service.
DISCUSSION AND OUTLOOK
At 200 AM EDT (0600 UTC), the center of Tropical Storm Grace was
located near latitude 18.1 North, longitude 74.5 West. Grace is
moving toward the west near 14 mph (22 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 continue to move near
or over the Tiburon Peninsula of Haiti during the next couple of
hours, and then move between southeastern Cuba and Jamaica this
afternoon. 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 Reserve reconnaissance aircraft indicate
that maximum sustained winds have increased to near 35 mph (55 km/h)
with higher gusts. Additional strengthening is forecast during the
next few days, and Grace could be near hurricane strength when it
approaches the Yucatan coast of Mexico in a couple of days.
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 possible in Haiti early this
morning, and in Jamaica this afternoon. 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.
RAINFALL: Grace is expected to produce the following rainfall
Over Haiti and the Dominican Republic...5 to 10 inches of rain with
isolated maximum totals of 15 inches are expected across the
southern terrain areas through today. This heavy rainfall may lead
to flash and urban flooding, and possible mudslides.
Over far southern Cuba, Jamaica, and the Cayman Islands....2 to 4
inches of rain with isolated maximum totals of 6 inches are expected
through Thursday. This heavy rainfall may lead to flash and urban
Over the northern Yucatan Peninsula...3 to 6 inches of rain with
isolated maximum totals of 10 inches are expected Wednesday into
Thursday, which may lead to areas of 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 500 AM EDT.