CHANGES WITH THIS ADVISORY: A Tropical Storm Warning has been issued from Sabine Pass to Cameron, Louisiana. The Hurricane Warning is changed to a Tropical Storm Warning from Matagorda to Freeport. The Storm Surge Warning from Port O'Connor to Sargent including Matagorda Bay has been discontinued. The Hurricane Warning is discontinued from south of Matagorda to Port O'Connor. The Hurricane Watch is discontinued from Freeport to San Luis Pass. The Tropical Storm Warning is discontinued from Port O'Connor to North of Port Aransas. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for...
- Sargent to Sabine Pass including Galveston Bay A Tropical Storm Warning is in effect for...
- Matagorda to Cameron A Storm Surge Watch is in effect for...
- Sabine Pass to Rutherford Beach Louisiana 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. 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. Interests elsewhere in southwestern Louisiana should monitor the progress of Nicholas. For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office.

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 additional rainfall of 5 to 10 inches from the upper Texas coastal area into central to southern Louisiana, far southern Mississippi and far southern Alabama, with isolated storm totals of 20 inches across central to southern Louisiana. Life threatening flash flooding impacts, especially in urbanized metropolitan areas, are possible across these regions. Widespread minor to isolated major river flooding is expected across portions of the upper Texas Gulf Coast and southern Louisiana and Mississippi. For the latest rainfall reports and wind gusts associated with Hurricane Nicholas see the companion storm summary at WBCSCCNS4 with the WMO header ACUS44KWBC or at the following link https://www.wpc.ncep.noaa.gov/discussions/nfdscc4.html

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... Sargent, TX to High Island, TX including Galveston Bay...3 5 ft High Island, TX to Rutherford Beach, LA...2 4 ft Port Aransas, TX to Sargent, TX...1 3 ft Aransas Bay, San Antonio Bay, and Matagorda Bay...1 3 ft Rutherford Beach, LA to Intracoastal City, LA...1 3 ft Sabine Lake and Calcasieu Lake...1 3 ft The deepest water will occur along the immediate coast in areas of onshore winds, 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 continue within the warning area across Texas coasts through this morning and start along the Louisiana coast by afternoon.

TORNADOES: A tornado or two will be possible today and tonight along the upper Texas Coast and southern Louisiana.

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

At 400 AM CDT (0900 UTC), the center of Tropical Storm Nicholas was located near latitude 29.3 North, longitude 95.6 West. Nicholas is moving toward the north northeast near 9 mph (15 km/h). The storm should move more slowly to the northeast later today and then eastward by Wednesday over Louisiana. Little motion is anticipated on Thursday. Maximum sustained winds have decreased to near 70 mph (110 km/h) with higher gusts. Nicholas should weaken further today and is forecast to become a tropical depression by Wednesday. Tropical storm force winds extend outward up to 125 miles (205 km) from the center. A NOAA station at Galveston Bay, Texas recently reported a 1 minute sustained wind of 54 mph (87 km/h) gusting to 68 mph (109 km/h).