1. Tropical storm conditions are expected across much of Cuba through Monday. Heavy rainfall is likely across Cuba and Jamaica through Monday and these rains could cause mudslides and life-threatening flash and urban flooding. Tropical storm conditions are expected in the Dry Tortugas on Monday.

2. Tropical storm conditions are possible over the Middle and LowerFlorida Keys on Monday.

3. While the details of the long-range track and intensity forecastsremain uncertain, Laura is forecast to strengthen over the Gulf ofMexico and there is an increasing risk of dangerous storm surge,wind, and rainfall impacts along portions of the U.S. Gulf Coast bythe middle of the week. This could result in a prolonged period ofhazardous weather for areas that are likely to be affected by Marco.Interests along the Gulf Coast should monitor the progress of Lauraand Marco and updates to the forecast during the next couple of days.

CHANGES WITH THIS ADVISORY:

A Tropical Storm Warning has been issued for the Dry Tortugas, Florida.

The government of Haiti has discontinued the Tropical Storm Warning for all of Haiti.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
- Little Cayman and Cayman Brac
- Cuban provinces of Camaguey, Las Tunas, Holguin, Guantanamo, Santiago de Cuba, Granma, Ciego De Avila, Sancti Spiritus, Villa Clara, Cienfuegos, Matanzas, Mayabeque, La Habana, Artemisa, Pinar del Rio, and the Isle of Youth
- Dry Tortugas

A Tropical Storm Watch is in effect for...
- Florida Keys from Craig Key to Key West and the Dry Tortugas

The Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, in this case within the next 12 to 24 hours.

A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, in this case within the next 24 hours.

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.

RAINFALL: Laura is expected to produce the following storm total rainfall accumulations through Tuesday:

Western Haiti, Jamaica, and Cuba: 4 to 8 inches, with maximum amounts of 12 inches.

Cayman Islands: 2 to 4 inches, maximum amounts of 6 inches.

Florida Keys, Turks and Caicos Islands, and the Northwest Bahamas: 1 to 2 inches.

Across the Greater Antilles this heavy rainfall could lead to lifethreatening flash and urban flooding, and the potential for mudslides.

From late Wednesday into Friday, Laura is expected to produce rainfall of 5 to 10 inches, with isolated maximum amounts of 15 inches across portions of the westcentral U.S. Gulf Coast near the Texas and Louisiana border north into portions of the lower Mississippi Valley. This rainfall could cause widespread flash and urban flooding, small streams and tributaries to overflow their banks, and the possibility of some minor river flooding to this region.

WIND: Tropical storm conditions are expected to spread westward within the warning area in Cuba through Monday. Tropical storm conditions are expected in Little Cayman, Cayman Brac, and the Dry Tortugas on Monday. Tropical storm conditions are possible within portions of the watch area in the Florida Keys Monday.

SURF: Swells generated by Laura are affecting portions of Hispaniola, eastern Cuba, the southeastern Bahamas and the Turks and Caicos Islands. These swells are expected to spread across central and western Cuba, the central and northwestern Bahamas, and the Florida Keys on Monday. Please consult products from your local weather office.

TORNADOES: An isolated tornado is possible across far southern Florida on Monday.

At 1100 PM EDT (0300 UTC), the center of Tropical Storm Laura was located near latitude 20.1 North, longitude 76.6 West. Laura is moving toward the westnorthwest near 21 mph (33 km/h) and this general motion with some decrease in forward speed is expected over the next couple of days. A turn toward the northwest is forecast by Wednesday. On the forecast track, the center of Laura will move near or over the southern coast of Cuba tonight and Monday, and move over the southeastern Gulf of Mexico Monday night and Tuesday. Laura is expected to move over the central and northwestern Gulf of Mexico Tuesday night and Wednesday.

Maximum sustained winds have increased to near 65 mph (100 km/h) with higher gusts. Gradual strengthening is expected, and Laura is forecast to become a hurricane by early Tuesday.

Tropicalstormforce winds extend outward up to 140 miles (220 km) from the center.

The estimated minimum central pressure is 1000 mb (29.53 inches).

Radar data from Cuba and satellite images indicate that Lauracontinues to gradually become better organized. Convection isquite deep on the south side of the circulation, and rainfall is likely very heavy over portions of eastern Cuba and Jamaica. A surface observation from Guantanamo Bay, Cuba, measured sustained winds of 52 kt with a wind gust to 63 kt a few hours ago. Based on this observation and the system's improved structure, the initial intensity is nudged up to 55 kt.

Laura continues to move swiftly to the west-northwest on the southside of a strong subtropical ridge, with the initial motionestimated to be 285/18 kt. The subtropical high is expected toexpand westward during the next couple of days, and that should keepLaura moving fairly quickly to the west-northwest near or over Cubathrough Monday and then across the south-central Gulf of Mexico onTuesday. The models suggest that a gradual turn to the northwest islikely by early Wednesday as the storm nears the western side of the ridge, followed by a northward motion after that. The details of the northwest and north turn are quite important when trying to figure out where the core of Laura is going to make landfall. However, at this time there is still a notable spread in the models and their ensemble members, meaning that it is still unclear exactly where the worst weather conditions will occur. The NHC track forecast is little changed from earlier and near the consensus aids. This forecast shows landfall along the northern Gulf coast in about 3 days.

The tropical storm is expected to move very near or over the entireisland of Cuba through Monday, and the interaction with the islandshould limit strengthening during that time. However, significantintensification is expected when the storm moves over the Gulf ofMexico due to a combination of favorable conditions of low windshear, high moisture, and warm SSTs. The NHC intensity forecast islargely an update of the previous one and lies near the middle ofthe guidance envelope. Although not explicitly forecast, Lauracould threaten the northwestern Gulf coast near major hurricanestrength.

Users are again reminded to not to focus on the exact details ofthe track or intensity forecast as the average NHC track error at72 h is around 100 miles and the average intensity error is around15 mph (13 kt). In addition, winds, storm surge, and rainfallhazards will extend far from the center.