1. Heavy rainfall could lead to flash and urban flooding over the Virgin Islands. Across Puerto Rico, the Dominican Republic and Haiti, heavy rainfall may lead to flash, urban and small stream flooding, along with the potential for mudslides.

2. Tropical storm conditions are possible over portions of Hispaniola Monday and Monday night.

3. There is a risk of some wind and rainfall impacts across the Turks and Caicos Islands, the Bahamas, Cuba, and Florida, but forecast uncertainty is much higher than usual. Interests in those areas should monitor the progress of Grace and updates to the forecast.

CHANGES WITH THIS ADVISORY: The Tropical Storm Warning for Puerto Rico and the U.S. Virgin Islands has been discontinued. The government of the Dominican Republic has changed the Tropical Storm Warning to a Tropical Storm Watch from the southern Haitian border to Samana. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Watch is in effect for...
- Entire coast of the Dominican Republic
- Entire coast of Haiti A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, in this case within 24 to 36 hours. Interests elsewhere in the the Turks and Caicos Islands, the southeastern Bahamas, and Cuba should monitor the progress of Grace. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, 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 and 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 tonight and Monday, and in Haiti on Monday and Monday night.

RAINFALL: The system is expected to produce the following rainfall amounts today into Tuesday: Virgin Islands...3 to 6 inches. This rainfall may produce scattered areas of flash and urban flooding. Over Puerto Rico...3 to 6 inches with isolated higher amounts. Heavy rainfall could lead to flash, urban and small stream flooding and possible mudslides. Over Haiti and the Dominican Republic...4 to 8 inches with isolated maximum totals of 15 inches across southern terrain areas. Heavy rainfall could lead to flash and urban flooding and possible mudslides from Monday into Tuesday. By mid to late week, heavy rainfall from this system could impact portions of Cuba, the Bahamas and Florida.

SURF: Swells generated by Grace will continue to affect portions of the Leeward Islands, the Virgin Islands and Puerto Rico and will reach portions of Hispaniola tonight and Monday. These swells are likely to cause life threatening surf and rip current conditions. Please consult products from your local weather office.

At 500 PM AST (2100 UTC), the center of Tropical Depression Grace was located near latitude 17.0 North, longitude 67.3 West. The depression is moving toward the west near 15 mph (24 km/h). A generally west northwestward motion is expected over the next few days. On the forecast track, Grace will move over Hispaniola on Monday, near or over eastern Cuba on Tuesday, and near or over west central Cuba on Wednesday. Maximum sustained winds have decreased to near 35 mph (55 km/h) with higher gusts. Little change in strength is forecast during the next 48 hours. The estimated minimum central pressure is 1011 mb (29.86 inches).

An earlier ASCAT pass over Grace suggested that the maximum winds were 25-30 kt and this has been confirmed by observations from a NOAA Hurricane Hunter aircraft. Aircraft and scatterometer data also suggest that the circulation is elongated and disorganized. Based on these data, the system is being downgraded to a 30-kt depression at this time. Since the system is below storm strength and is passing by Puerto Rico, the Tropical Storm Warnings for Puerto Rico and the U.S. Virgin Islands have been discontinued. The island of Hispaniola is kept under a Tropical Storm Watch given the possibility that the system could restrengthen tonight or tomorrow morning before moving over land. Most of the reliable guidance shows little change in strength over the next 2-3 days. This seems reasonable since the circulation will be interacting with the mountainous land mass of Hispaniola and Cuba for the next 72 hours. The official intensity forecast is near or a little above the DSHIPS and LGEM guidance during that time. Some restrengthening is possible later in the forecast period when the system is expected to move over the Gulf of Mexico. However, the global models are not very bullish on intensification in 4-5 days, perhaps due to drier air.

The system has moved mainly westward today, but the track models are generally in agreement on a west-northwestward motion over the forecast period. This is consistent with a well-defined mid-level ridge staying in place over the southwestern Atlantic and across Florida during this week. The official track forecast has been shifted a little south of the previous one, following the multi-model consensus.