CHANGES WITH THIS ADVISORY: The Tropical Storm Warning has been extended eastward to Freeport, Texas. A Storm Surge Warning has been issued for the coast of Texas from Port Aransas to San Luis Pass, including Aransas Bay, San Antonio Bay, and Matagorda Bay.

A Hurricane Watch has been issued for the coast of Texas from Port Aransas to Sargent.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for...
- Port Aransas to San Luis Pass Texas
- Aransas Bay, San Antonio Bay, and Matagorda Bay A Hurricane Watch is in effect for...
- Port Aransas to Sargent Texas A Tropical Storm Warning is in effect for...
- Mouth of the Rio Grande to Freeport Texas
- Barra el Mezquital to the U.S./Mexico border A Storm Surge Watch is in effect for...
- Mouth of the Rio Grande to High Island Texas A Tropical Storm Watch is in effect for...
- North of Port Aransas to High Island Texas

A Storm Surge Warning means there is a danger of life threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. 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 tropical storm force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. Interests elsewhere along the upper Texas coast should monitor the progress of this system. 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 Nicholas can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4, WMO header WTNT44 KNHC and on the web at hurricanes.gov/graphics_at4.shtml?key_messages

RAINFALL: Nicholas is expected to produce storm total rainfall of 8 to 16 inches, with isolated maximum amounts of 20 inches, across portions of the middle and upper Texas coastal areas today through the middle of the week. Across the rest of coastal Texas into southwest Louisiana rainfall of 5 to 10 inches is expected. This rainfall may produce areas of considerable flash and urban flooding, especially in highly urbanized metropolitan areas. Additionally, there is the potential for isolated minor to moderate river flooding.

Over the northeastern portions of the Mexican state of Tamaulipas rainfall amounts of 2 to 5 inches can be expected today into Monday.

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... Port O'Connor to San Luis Pass TX including Matagorda Bay...3 5 ft Mouth of the Rio Grande to Port O'Connor, TX...2 4 ft San Luis Pass to High Island, TX including Galveston Bay...2 4ft Baffin Bay, Corpus Christi Bay, Aransas Bay and San Antonio Bay...2 4 ft High Island, TX to Intracoastal City including Sabine Lake and Calcasieu Lake..1 3 ft The deepest water will occur along the immediate coast in areas of onshore flow, where the surge will be accompanied by large and dangerous waves. Surge related 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.

WIND: Tropical storm conditions are expected to first reach the coast within the warning area in northeastern Mexico and southern Texas Monday morning, making outside preparations difficult or dangerous. These conditions will spread northward within the warning area through Monday night. Hurricane conditions are possible in the Hurricane Watch area Monday night. Tropical storm conditions are possible within the watch area by late Monday night or early Tuesday.

TORNADOES: A tornado or two will be possible Monday into Monday night across the middle and lower Texas coast.

SURF: Swells generated by Nicholas will begin affecting portions of the northwest Gulf coast later tonight and continue into Tuesday. These swells are likely to cause life threatening surf and rip current conditions. Please consult products from your local weather office.