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BULLETIN
Tropical Storm Grace Intermediate Advisory Number 19A
NWS National Hurricane Center Miami FL       AL072021
200 AM EDT Wed Aug 18 2021
 
...GRACE FORECAST TO BECOME A HURRICANE LATER TODAY...
...HEAVY RAINFALL AND FLASH FLOOD THREAT CONTINUES IN JAMAICA...
 
 
SUMMARY OF 200 AM EDT...0600 UTC...INFORMATION
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LOCATION...18.7N 80.1W
ABOUT 85 MI...140 KM ESE OF GRAND CAYMAN
ABOUT 70 MI...110 KM S OF CAYMAN BRAC
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES
 
 
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
 
None.
 
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
 
A Hurricane Warning is in effect for...
* Yucatan Peninsula of Mexico from Cancun to Punta Herrero,
including Cozumel
 
A Hurricane Watch is in effect for...
* Cayman Islands
 
A Tropical Storm Warning is in effect for...
* Jamaica
* Southern coast of the Cuban provinces of Granma, Las Tunas, and
Camaguey
* Cayman Islands
* Yucatan Peninsula of Mexico from north of Cancun to Dzilam
* Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto
Costa Maya
 
A Tropical Storm Watch is in effect for...
* 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
* North and west coasts of the Yucatan Peninsula from west of
Dzilam to Campeche
 
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 Hurricane Watch means that hurricane conditions are possible
within the watch area.
 
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 the Yucatan Peninsula of Mexico should
monitor the progress of Grace.  Additional watches or warnings may
be required 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 by an Air Force Reserve reconnaissance aircraft and 
satellites near latitude 18.7 North, longitude 80.1 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 away
from the western coast of Jamaica and and move near or over the 
Cayman Islands later this morning. Grace will approach the Yucatan 
peninsula of Mexico tonight or early Thursday.
 
Data from the reconnaissance aircraft indicate that maximum 
sustained winds remain near 60 mph (95 km/h) with higher gusts. 
Grace is forecast to strengthen into a hurricane by tonight, with 
some additional strengthening possible prior to the center reaching 
the eastern Yucatan Peninsula.
 
Tropical-storm-force winds extend outward up to 115 miles (185 km)
mainly north through east of the center. A reporting station near 
Rum Point Beach on the north shore of Grand Cayman recently 
measured a sustained wind of 34 mph (55 km/h) and a gust to 51 mph 
(82 km/h).
 
The latest minimum central pressure estimated from reconnaissance
aircraft data is 1000 mb (29.53 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
www.hurricanes.gov/graphics_at2.shtml?key_messages.
 
WIND:  Tropical storm conditions are expected to continue over
portions of western Jamaica for a few more hours. Tropical storm 
conditions
are expected along a portion of the southern coast of Cuba within
the warning area and over the Cayman Islands through this morning. 
Hurricane conditions are possible in the Cayman Islands later this 
morning. 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, with tropical storm conditions 
beginning as early as this evening.
 
RAINFALL:  The system is expected to produce the following rainfall
amounts:
 
Over Jamaica, the Cayman Islands, and portions of the Yucatan
Peninsula....3 to 6 inches of rain with isolated maximum totals of
10 inches are expected through Thursday. This heavy rainfall may
lead to flash and urban flooding, and across Jamaica, mudslides will
also be possible.
 
STORM SURGE:  A storm surge could raise water levels as high as 1 to
3 ft above normal tide levels in portions of the Cayman Islands.
 
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 destructive waves.
 
SURF:  Swells generated by Grace will spread westward from Jamaica
to 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 ADVISORY
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Next complete advisory at 500 AM EDT.
 
$$
Forecaster Stewart
 
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