000 WTNT32 KNHC 180248 TCPAT2 BULLETIN Tropical Storm Grace Advisory Number 19 NWS National Hurricane Center Miami FL AL072021 1100 PM EDT Tue Aug 17 2021 ...GRACE FORECAST TO BECOME A HURRICANE ON WEDNESDAY... ...HEAVY RAINFALL AND FLASH FLOOD THREAT CONTINUES IN JAMAICA... SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...18.4N 79.2W ABOUT 145 MI...235 KM ESE OF GRAND CAYMAN ABOUT 60 MI...95 KM W OF NEGRIL JAMAICA 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: The government of Mexico has issued a Tropical Storm Warning along the north coast of the Yucatan Peninsula from Cabo Catoche westward to Dzilam. A Tropical Storm Watch has been issued for the north and west coasts of the Yucatan Peninsula from west of Dzilam to Campeche. The government of Cuba has discontinued the Tropical Storm Warning for the Cuban province of Santiago de Cuba. 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 early Wednesday. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 1100 PM EDT (0300 UTC), the center of Tropical Storm Grace was located near latitude 18.4 North, longitude 79.2 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 overnight. Grace is forecast to move near or over the Cayman Islands early Wednesday, and then approach the Yucatan peninsula of Mexico late Wednesday or early Thursday. Data from NOAA and Air Force Reserve reconnaissance aircraft indicate that maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Grace is forecast to strengthen into a hurricane on Wednesday, with some additional strengthening possible prior to the center reaching the Yucatan Peninsula. Tropical-storm-force winds extend outward up to 115 miles (185 km) primarily to the east of the center. 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 Jamaica for a few more hours. Tropical storm conditions are expected along a portion of the southern coast of Cuba within the warning area through tonight, and over the Cayman Islands beginning by early Wednesday. Hurricane conditions are possible in the Cayman Islands by early Wednesday. Tropical storm conditions are possible along the southern coast of Cuba within the watch area tonight and Wednesday. Hurricane conditions are expected within the warning area in the Yucatan Peninsula of Mexico on Wednesday night with tropical storm conditions beginning as early as Wednesday 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 Wednesday 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 ------------- Next intermediate advisory at 200 AM EDT. Next complete advisory at 500 AM EDT. $$ Forecaster Brown