1. Heavy rainfall across the Dominican Republic, 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 the Dominican Republic.

2. Tropical storm conditions are possible over portions of Hispaniola overnight, 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 possibly other portions of the southern coast of Cuba Tuesday evening through Wednesday morning.

3. There is a increasing risk of wind, rainfall, and storm surge impacts on 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 Watch for the southern coast of the province of Pinar del Rio. 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 Haiti
- Jamaica
- 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 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 in the Yucatan Peninsula of Mexico should monitor the progress of Grace. Watches may be required for portions of the Yucatan coast early Tuesday. 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 Haiti overnight, 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 far southern Cuba, Jamaica, and the Cayman Islands....2 to 4 inches of rain with isolated maximum totals of 6 inches are expected through Thursday. This heavy rainfall may lead to flash and urban flooding.

Over the northern Yucatan Peninsula...3 to 6 inches of rain with isolated maximum totals of 10 inches are expected Wednesday into Thursday, which may lead to areas of flash and urban flooding.

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 PM EDT (0300 UTC), the center of Tropical Depression Grace was located near latitude 18.2 North, longitude 73.8 West. The depression 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 near or over the Tiburon Peninsula of Haiti during the next couple of hours, and then move between southeastern Cuba and Jamaica on Tuesday. Grace is forecast to move near the Cayman Islands Tuesday night and then approach the Yucatan peninsula of Mexico late Wednesday or early Thursday. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Strengthening is forecast during the next few days, and Grace is forecast to become a tropical storm on Tuesday. Further strengthening is anticipated before Grace approaches the coast of Mexico in a few days. The estimated minimum central pressure is 1006 mb (29.71 inches).

IR and microwave imagery during the past few hours indicate that Grace's convective organization has improved a little since this afternoon. However, it is currently unknown if that has translated to a better-defined surface wind field. Dvorak intensity estimates from TAFB and SAB at 00Z supported tropical storm strength, and it is possible Grace has redeveloped sustained winds of that magnitude. A hurricane hunter aircraft is scheduled to investigate Grace in a few hours, so it seems prudent to avoid making a big change before the plane gets there. Grace is therefore conservatively maintained as a 30 kt depression for this advisory. Regardless of Grace's exact intensity right now, the immediate threat is still torrential rainfall across Hispaniola overnight, which will likely cause severe flooding in some locations.

The initial motion estimate is 280/12 kt. Confidence in the track forecast has increased considerably during the past 24 h and the track model spread is low. A mid-level ridge is forecast to build over the Gulf of Mexico during the next several days, which should keep Grace on a generally westward or west-northwestward track through day 5. Once Grace moves away from Haiti, it should remain over water until it reaches the Yucatan peninsula late Wednesday or early Thursday. Very little change was made to the official track forecast, which is based primarily on the multi-model consensus TVCN.

Now that Grace is forecast to avoid all major land masses for the next couple of days, all of the intensity guidance calls for some strengthening to occur. That said, with the exception of the COAMPS-TC model, the intensity guidance as a whole shows a slower rate of strengthening than it did 6 h ago. The NHC forecast is now very near the IVCN intensity consensus throughout the forecast, including over the Gulf of Mexico where it continues to show Grace reaching hurricane strength. Despite the slightly lower guidance for this forecast, it still can not be ruled out that Grace will reach hurricane strength over the western Caribbean. When the hurricane hunter aircraft reaches Grace in a couple hours and provides more information about the current organization of cyclone, we should have a better feel for how quickly it could intensify prior to reaching the coast of Mexico.