000 WTNT32 KNHC 171756 TCPAT2 BULLETIN Tropical Storm Grace Intermediate Advisory Number 17A NWS National Hurricane Center Miami FL AL072021 200 PM EDT Tue Aug 17 2021 ...HEAVY RAINS SPREADING OVER JAMAICA AND BEGINNING TO SPREAD OVER EASTERN CUBA... SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...18.5N 77.5W ABOUT 25 MI...40 KM E OF MONTEGO BAY JAMAICA ABOUT 250 MI...400 KM ESE OF GRAND CAYMAN MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...W OR 280 DEGREES AT 15 MPH...24 KM/H MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Tropical Storm Watch for Haiti is discontinued. 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... * Jamaica * 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... * 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 dangerous. 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 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 200 PM EDT (1800 UTC), the center of Tropical Storm Grace was located near latitude 18.5 North, longitude 77.5 West. Grace is moving toward the west near 15 mph (24 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 the northern coast of Jamaica this afternoon. Grace is forecast to move near or over the Cayman Islands late tonight and early Wednesday, and then approach the Yucatan peninsula of Mexico late Wednesday or early Thursday. Maximum sustained winds are near 50 mph (85 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 70 miles (110 km) from the center. Kingston, Jamaica recently reported a wind gust to 46 mph (74 km/h). 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 www.hurricanes.gov/graphics_at2.shtml?key_messages. WIND: Tropical storm conditions are expected to continue over portions of Jamaica today. Tropical storm conditions are expected along the southern coast of Cuba within the warning area later this afternoon through this evening, and over the Cayman Islands beginning tonight and into early Wednesday. Tropical storm conditions are possible along the southern coast of Cuba within the watch area tonight and Wednesday. RAINFALL: The system is expected to produce the following rainfall amounts: Over Haiti...an additional 2 to 4 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 mudslides. 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 10 inches are expected through Thursday. This heavy rainfall may lead to flash and urban flooding. STORM SURGE: A dangerous storm surge will raise water levels by as much as 2-4 feet 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 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 ADVISORY ------------- Next complete advisory at 500 PM EDT. $$ Forecaster Pasch