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Hurricane Grace Intermediate Advisory Number 21A
NWS National Hurricane Center Miami FL AL072021
200 PM EDT Wed Aug 18 2021
...GRACE HEADED FOR THE YUCATAN PENINSULA OF MEXICO...
SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
ABOUT 295 MI...475 KM E OF TULUM MEXICO
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.38 INCHES
WATCHES AND WARNINGS
CHANGES WITH THIS ADVISORY:
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
A Tropical Storm Warning is in effect for...
* Cayman Islands
* Yucatan Peninsula of Mexico from north of Cancun to Campeche
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
A Tropical Storm Watch is in effect for...
* Southern coast Cuban province of Pinar del Rio, as well as Isla
de la Juventud
A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous. Preparations to protect life and property should be
rushed to completion.
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.
Interests elsewhere in eastern mainland Mexico should monitor the
progress of Grace.
For storm information specific to your area, please monitor
products issued by your national meteorological service.
DISCUSSION AND OUTLOOK
At 200 PM EDT (1800 UTC), the center of Hurricane Grace was located
near latitude 19.6 North, longitude 83.0 West. Grace is moving
toward the west-northwest near 15 mph (24 km/h). A general
west-northwestward to westward motion is expected for the next
several days. On the forecast track, Grace is expected to make
landfall in the eastern Yucatan Peninsula Thursday morning, move
over the Yucatan Peninsula on Thursday, and move over the
southwest Gulf of Mexico Thursday night or early Friday.
Maximum sustained winds are near 75 mph (120 km/h) with higher
gusts. Some strengthening is forecast before the center of Grace
reaches the Yucatan Peninsula. Weakening will occur while the
center moves over the Yucatan Peninsula on Thursday, with
restrengthening expected when Grace moves over the southwest Gulf of
Mexico on Friday.
Hurricane-force winds extend outward up to 25 miles (35 km) from
the center and tropical-storm-force winds extend outward up to 140
miles (220 km).
The minimum central pressure estimated from Air Force Hurricane
Hunter aircraft observations is 995 mb (29.38 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 along the southern
coast of Cuba within the watch area through today. Hurricane
conditions are expected within the warning area in the Yucatan
Peninsula of Mexico late tonight or early Thursday, with tropical
storm conditions beginning as early as this evening.
Grace is expected to produce the following rainfall amounts:
Over the Cayman Islands, portions of the Yucatan Peninsula and
Veracruz State of Mexico....4 to 8 inches with isolated maximum
totals of 12 inches are expected through Friday night. This
heavy rainfall could lead to flash and urban flooding, with
mudslides possible in Veracruz.
STORM SURGE: A dangerous storm surge will raise water levels by as
much as 3 to 5 ft above normal tide levels along the immediate
coast near and to the north of where the center makes landfall in
the northeastern Yucatan Peninsula late tonight or early Thursday.
Near the coast, the surge will be accompanied by large and
SURF: Swells generated by Grace will spread westward from Jamaica
and the Cayman Islands to the southern coast of Cuba and the Yucatan
Peninsula of Mexico through Thursday. 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 PM EDT.