1. Laura is forecast to reach the northwestern Gulf Coast as a hurricane late Wednesday and early Thursday. Do not focus on the details of the official forecast given the typical uncertainty in NHC's

2.to

3.day track and intensity predictions. In addition, storm surge, wind, and rainfall hazards will extend well away from Laura's center along the Gulf Coast. 2. There is a risk of life-threatening storm surge from San Luis Pass, Texas, to Ocean Springs, Mississippi, within the next

4. hours, and a storm surge watch has been issued for these areas outside of the southeast Louisiana Hurricane and Storm Damage Risk Reduction System. Residents in these areas should follow any advice given by local officials.3. Hurricane conditions are possible by late Wednesday from Port Bolivar, Texas, to west of Morgan City, Louisiana, with tropical storm conditions possible by Wednesday afternoon, and a hurricane watch has been issued. Additional hurricane watches may be needed farther south along the Texas coast if the track forecast shifts toward the south and west tonight and Tuesday. 4. Tropical storm conditions and heavy rainfall are expected across central and western Cuba through tonight. These rains could cause mudslides and life-threatening flash and urban flooding.

CHANGES WITH THIS ADVISORY:

A Storm Surge Watch is in effect from San Luis Pass, Texas, to Ocean Springs, Mississippi, including Lake Pontchartrain, Lake Maurepas, and Lake Borgne for areas outside of the southeast Louisiana Hurricane and Storm Damage Risk Reduction System.

A Hurricane Watch is in effect from Port Bolivar, Texas, to west of Morgan City, Louisiana.

A Tropical Storm Watch is in effect from south of Port Bolivar to San Luis Pass Texas and from Morgan City to the Mouth of the Mississippi River.

The Tropical Storm Warning for Little Cayman and Cayman Brac has been discontinued.

The Tropical Storm Warning for the Cuban provinces of Camaguey and Las Tunas has been discontinued.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Watch is in effect for...
- San Luis Pass Texas to Ocean Springs Mississippi
- Lake Pontchartrain, Lake Maurepas, and Lake Borgne

A Hurricane Watch is in effect for...
- Port Bolivar Texas to west of Morgan City Louisiana

A Tropical Storm Warning is in effect for...
- Cuban provinces of Ciego De Avila, Sancti Spiritus, Villa Clara, Cienfuegos, Matanzas, Mayabeque, La Habana, Artemisa, Pinar del Rio, and the Isle of Youth
- Florida Keys from Craig Key to Key West
- Dry Tortugas

A Tropical Storm Watch is in effect for...
- South of Port Bolivar to San Luis Pass Texas
- Morgan City Louisiana to the Mouth of the Mississippi River

A Storm Surge Watch means there is a possibility of life threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov.

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 tropicalstormforce 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.

A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 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.

Key messages for Laura can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC. STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... High Island TX to Morgan City LA including Sabine Lake, Calcasieu Lake, and Vermilion Bay...711 ft Port Bolivar TX to High Island TX...46 ft Morgan City LA to Mouth of the Mississippi River...46 ft Mouth of the Mississippi River to Ocean Springs MS including Lake Borgne...35 ft San Luis Pass TX to Port Bolivar TX...24 ft Galveston Bay...24 ft Lake Pontchartrain and Lake Maurepas...24 ft The deepest water will occur along the immediate coast near and to the right of the landfall location, where the surge will be accompanied by large and destructive waves. Surgerelated flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office.

RAINFALL: Laura is expected to produce the following storm total rainfall accumulations into tonight: Western Jamaica, Western Cuba and the Cayman Islands: 4 to 6 inches, with maximum amounts of 10 inches. Across the Greater Antilles this heavy rainfall could lead to lifethreatening flash and urban flooding, and the potential for mudslides. From Wednesday afternoon into Saturday, Laura is expected to produce rainfall of 4 to 8 inches, with isolated maximum amounts of 12 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 to overflow their banks, and minor to isolated moderate river flooding.

WIND: Tropical storm conditions are expected to spread westward within the warning area in western Cuba through this evening. Tropical storm conditions are also expected within the warning area in the middle and lower Florida Keys and the Dry Tortugas tonight. Hurricane conditions are possible in the hurricane watch area along the Gulf Coast by late Wednesday, with tropical storm conditions possible by Wednesday afternoon. SURF: Swells generated by Laura are affecting portions of Cuba, the central Bahamas, and the Florida Keys. Swells are expected to spread northward along portions of the west coast of Florida peninsula and the coast of the Florida panhandle on Tuesday and Tuesday night, and reach the northern and northwest Gulf coast by Wednesday. These swells are likely to cause lifethreatening surf and rip current conditions. Please consult products from your local weather office.

TORNADOES: An isolated tornado is possible through tonight across the Florida Keys.

At 500 PM EDT (2100 UTC), the center of Tropical Storm Laura was located near latitude 21.7 North, longitude 82.2 West. Laura is moving toward the westnorthwest near 20 mph (31 km/h), and this general motion with some decrease in forward speed is expected over the next day or so. A turn toward the northwest is forecast by Wednesday, and a northwestward to northnorthwestward motion should continue through Wednesday night. On the forecast track, the center of Laura will cross western Cuba this evening and move into the southeastern Gulf of Mexico overnight. Laura is then forecast to move over the central and northwestern Gulf of Mexico Tuesday night and Wednesday, and approach the northwestern coast of the Gulf of Mexico Wednesday night.

Maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Strengthening is expected when the storm moves over the Gulf of Mexico, and Laura is foreast to become a hurricane by late Tuesday. Additional strengthening is forecast on Wednesday.

Tropicalstormforce winds extend outward up to 175 miles (280 km) primarily to the northeast and east of the center.

The estimated minimum central pressure is 1001 mb (29.56 inches).

The satellite presentation of the tropical storm has improved somewhat with deep convection remaining over the center, and an increase in banding over the southeastern portion of the circulation. Earlier aircraft and scatterometer data, however, indicated that there has been little change in strength today, and the initial intensity remains 50 kt. These observations have shown the the stronger winds are located in the convective band well east and southeast of the center, and that the system currently lacks an inner core. This is likely the reason that Laura has not been able to strengthen while it has moved over water today. The aircraft also reported a fairly stable minimum pressure of 1001-1003 mb during its mission this morning and early afternoon.

The intensity forecast philosophy remains the same as the previous advisory. Once Laura moves over the southeastern Gulf of Mexico tonight, a combination of warm sea surface temperatures and low vertical wind shear should allow for steady strengthening. The latest iterations of the global and regional hurricane models continue to show significant deepening while Laura traverses the Gulf of Mexico, and a period or rapid strengthening is possible once an inner core is able to organize. The statistical guidance is again on the lower side of the intensity forecast envelope while the HWRF and CTCI models bringing Laura to major hurricane strength. The NHC intensity forecast is again between these solutions and is close to the consensus aids.

The initial motion estimate is 290/16 kt. A deep-layer ridge overthe western Atlantic is expected to build westward during the nextday or so. By early Wednesday, a mid- to upper-level trough overthe south-central United States is forecast to erode the westernportion of the ridge, which should cause Laura to turn northwestwardand then northward toward the northwestern Gulf coast. After landfall, Laura or its remnants are expected to become embedded in the mid-latitude westerlies and recurve over the eastern U.S. on days 4 and 5. The latest runs of the dynamical models are in a little better agreement, but the 1200 UTC ECMWF ensemble mean is located considerably left of its deterministic run, indicating that uncertainty regarding the track forecast remains. Users are again reminded to not to focus on the exact details of the track or intensity forecasts as the average NHC track error at 60 h is around 90 miles and the average intensity error is close to 15 mph. In addition, wind, storm surge, and rainfall hazards will extend far from the center.The new NHC forecast necessitates the issuance of storm surge and hurricane watches for portions of the U.S. Gulf Coast.