1. Heavy rainfall across Haiti, Cuba, Jamaica, the Cayman Islands, and the northern Yucatan Peninsula may lead to flash, urban, and small stream flooding, with the potential for mudslides highest in Haiti and Jamaica.

2. Tropical storm conditions are expected over portions of Jamaica today, and over the Cayman Islands later today and tonight. Tropical storm conditions are expected over portions of the southern coast of Cuba today in the warning area, spreading westward to possibly other portions of the southern coast of Cuba this evening through Wednesday morning.

3. There is an increasing risk of wind, rainfall, and storm surge impacts on the Yucatan Peninsula of Mexico Wednesday night and Thursday, and a Hurricane Warning will likely be needed for that area later today.

CHANGES WITH THIS ADVISORY: None. 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...
- 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 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.

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 in Jamaica today. Tropical storm conditions are possible in portions of Haiti for the next several hours. 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: 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.

At 1100 AM EDT (1500 UTC), the center of Tropical Storm Grace was located near latitude 18.3 North, longitude 76.8 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. The estimated minimum central pressure is 1005 mb (29.68 inches).

The cloud pattern of Grace is gradually becoming better organized on satellite images, but the system still lacks distinct banding features over the eastern semicircle. Cirrus-level outflow from the system appears to be well defined. Flight-level and SFMR-observed surface winds, as well as dropsonde measurements, support an intensity of 45 kt for this advisory.

Not much change in intensity is likely through this afternoon while the circulation of Grace interacts with the island of Jamaica. Thereafter, since the cyclone will be over the very high heat content waters of the northwestern Caribbean Sea with modestly low vertical shear tonight and Wednesday, strengthening is anticipated. Grace will likely become a hurricane tomorrow and continue to intensify before moving over the Yucatan Peninsula. The interaction with that land mass is expected to temporarily interrupt strengthening, with some reintensification over the Bay of Campeche in 3-4 days. The official intensity forecast is near the model consensus for the first half of the forecast period, but below the consensus for the latter part of the period owing to the inherent uncertainties for that extended time frame.

Grace continues to move just a little north of due west, or at about 280/13 kt. A well-defined 500 mb ridge should remain entrenched to the north of the tropical cyclone for the next several days. Therefore, a continued west to west-northwestward track is likely to continue for most, if not all, of the forecast period. The official forecast is close to the previous one through 72 hours and just slightly south of it at 4-5 days. This is very similar to the latest multi-model consensus prediction.