Alabama 811 | Know What's Below.

7 am Advisory — Nicholas Moving Erratically Just Offshore of Northeastern Mexico

| September 13, 2021 @ 7:10 am

SUMMARY OF 700 AM CDT…1200 UTC…INFORMATION
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LOCATION…25.4N 96.9W
ABOUT 40 MI…65 KM SSE OF MOUTH OF THE RIO GRANDE
ABOUT 210 MI…335 KM S OF PORT O’CONNOR, TEXAS
MAXIMUM SUSTAINED WINDS…60 MPH…95 KM/H
PRESENT MOVEMENT…NNW OR 345 DEGREES AT 5 MPH…7 KM/H
MINIMUM CENTRAL PRESSURE…1001 MB…29.56 INCHES

WATCHES AND WARNINGS
——————–
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 Freeport, Texas

A Tropical Storm Warning is in effect for…
* Mouth of the Rio Grande to High Island, Texas
* Barra el Mezquital to the U.S./Mexico border

A Storm Surge Watch is in effect for…
* Mouth of the Rio Grande to Port Aransas Texas
* San Luis Pass, Texas to Rutherford Beach Louisiana, including Galveston Bay
* Baffin Bay and Corpus Christi Bay

A Tropical Storm Watch is in effect for…
* East of High Island, Texas to Sabine Pass

DISCUSSION AND OUTLOOK
———————-
At 700 AM CDT (1200 UTC), the center of Tropical Storm Nicholas was located near latitude 25.4 North, longitude 96.9 West. Nicholas has been drifting toward the north-northwest near 5 mph (7 km/h). The storm should move northward later today at a faster forward speed, and turn north-northeastward on Tuesday. On the forecast track, the center of Nicholas will pass near or just offshore the coasts of northeastern Mexico and south Texas this morning, and move onshore along the coast of south or central Texas late this afternoon or evening.

Maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Strengthening is forecast today, and Nicholas could reach the northwest Gulf coast as a hurricane. Weakening is anticipated on Tuesday and Wednesday while Nicholas moves over land.

Tropical-storm-force winds extend outward up to 115 miles (185 km) from the center. A Weatherflow station on South Padre Island, Texas, recently reported a wind gust to 45 mph (72 km/h).

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

HAZARDS AFFECTING LAND
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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 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.

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
San Luis Pass, TX to Rutherford Beach, LA including Galveston Bay…2-4 ft
Mouth of the Rio Grande to Port O’Connor, TX…2-4 ft
Baffin Bay, Corpus Christi Bay, Aransas Bay and San Antonio Bay…2-4 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 first reach the coast within the warning area in northeastern Mexico and southern Texas this morning, making outside preparations difficult or dangerous. These conditions will spread northward within the warning area through tonight. Hurricane conditions are possible in the Hurricane Watch area as early as this afternoon. Tropical storm conditions are possible within the watch area by tonight or early Tuesday.

TORNADOES: A tornado or two will be possible today into tonight across the Texas coast.

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

Category: ALL POSTS, Severe Weather, Tropical

About the Author ()

Scott Martin is an operational meteorologist, professional graphic artist, musician, husband, and father. Not only is Scott a member of the National Weather Association, but he is also the Central Alabama Chapter of the NWA president. Scott is also the co-founder of Racecast Weather, which provides forecasts for many racing series across the USA. He also supplies forecasts for the BassMaster Elite Series events including the BassMaster Classic.

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