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

2. Tropical storm conditions are possible over portions of Hispaniola today and tonight, and over Jamaica on Tuesday. Tropical storm conditions are expected over portions of the southern coast of Cuba on Tuesday, spreading westward to the Cayman Islands and other portions of the southern coast of Cuba Tuesday evening through Wednesday morning.

3. There is a increasing risk of wind and rainfall impacts over the Yucatan Peninsula of Mexico Wednesday night and Thursday. Interests there areas should monitor the progress of Grace and updates to the forecast.

CHANGES WITH THIS ADVISORY: The government of Cuba has issued a Tropical Storm Warning for the southern coasts of the provinces of Santiago de Cuba, Granma, Las Tunas, and Camaguey. A Tropical Storm Watch has been issued for the southern coasts of the provinces of Ciego de Avila, Sancti Spiritus, Cienfuegos, and Matanzas, as well as Isla de la Juventud. The government of the Cayman Islands has issued a Tropical Storm Warning for the Cayman Islands. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for...
- 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 the Dominican Republic
- Entire coast of Haiti
- Jamaica
- Southern coast of the Cuban provinces of Ciego de Avila, Sancti Spiritus, Cienfuegos, and Matanzas, as well as Isla de la Juventud. 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, generally within 48 hours. Interests elsewhere in Cuba and the Yucatan Peninsula of Mexico should monitor the progress of Grace. Additional watches or warnings are possible later today or tonight. 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 possible in the Dominican Republic today, in Haiti today into tonight, and in Jamaica on Tuesday. Tropical storm conditions are expected along the southern coast of Cuba within the warning area on Tuesday, and over the Cayman Islands beginning late Tuesday into early Wednesday. Tropical storm conditions are possible along the southern coast of Cuba within the watch area Tuesday night and Wednesday.

RAINFALL: Grace is expected to produce the following rainfall amounts: Over Haiti and the Dominican Republic...5 to 10 inches of rain with isolated maximum totals of 15 inches are expected across the southern terrain areas through Tuesday. This heavy rainfall may lead to flash and urban flooding, and possible mudslides. Over Cuba, Jamaica, and the Cayman Islands...2 to 4 inches of rain with isolated maximum totals of 6 inches are expected through Thursday.

SURF: Swells generated by Grace will continue to affect portions of Hispaniola and Puerto Rico over the next day or so, and will spread westward to Jamaica, the Cayman Islands, and the southern coast of Cuba. 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 Depression Grace was located near latitude 17.7 North, longitude 71.4 West. Grace is moving toward the west near 15 mph (24 km/h). A westward to west northwestward motion is expected over the next several days. On the forecast track, the center of Grace will pass near the southern coast of Hispaniola today and tonight, and then pass between Jamaica, Cuba, and the Cayman Islands on Tuesday and Wednesday. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Some strengthening is forecast during the next few days, and Grace is expected to become a tropical storm again by Tuesday. The estimated minimum central pressure is 1007 mb (29.74 inches).

Air Force Reserve and NOAA Hurricane Hunters were both able to locate a center for Grace--probably the most well-defined center observed over the past few days. That center now appears to be moving onshore along the Barahona Peninsula of the Dominican Republic as we speak. The planes measured several possible areas of tropical-storm-force winds from the SFMR, however these observations have not been supported by the more reliable 925-mb flight-level winds for weaker systems, which were only as high as 38 kt, and warrant maintaining the 30-kt initial intensity. Dropsonde data indicate that the central pressure has fallen to 1007 mb.

The aircraft fixes confirm that Grace is moving westward, or 280/13 kt. High pressure over the western Atlantic is forecast to slide westward over the southeastern United States during the next several days, which should keep Grace on a westward to west- northwestward trajectory for the entire 5-day forecast period. This scenario is agreed upon by all of the available track models, and the new NHC track forecast has only been nudged slightly southward from the previous forecast based on the latest consensus aids.

Grace's intensity forecast remains complicated by interaction with land and the possibility of some westerly shear during the forecast period. However, the southern shift in the forecast track takes the center of Grace more definitively over very warm 30 degrees Celsius waters in the northwestern Caribbean Sea. Therefore, gradual strengthening is anticipated while Grace approaches the Yucatan coast of Mexico. Once the system reaches the Gulf of Mexico, the shear appears to decrease, and conditions there will likely be conducive for additional strengthening. In fact, many of the models, including the consensus aids, bring Grace to hurricane intensity, and the NHC intensity forecast has therefore been bumped upward, bringing Grace very near hurricane strength by the end of the forecast period.