Nicholas has been downgraded to a tropical storm on Tuesday after making landfall along the Texas coast as a Category 1 hurricane.
The storm is packing sustained winds of up to 73 mph (117 kph) as it makes its way east from Texas to Louisiana. The National Hurricane Center said residents are facing "life-threatening storm surge inundation" from Sargent to Sabine Pass, Texas, including Galveston Bay, a popular beachside retreat for residents of neighboring Houston.
The Center warned that tropical storm conditions will continue from San Luis Pass, Texas to Cameron, Louisiana.
Water levels from Matagorda Bay to Galveston Bay were 3-5 feet above high tide levels when Nicholas made landfall, while water levels in Manchester reached 6 feet above normal high tide levels -- the fourth highest ever recorded since 1995, according to the National Oceanic and Atmospheric Administration.
Over half a million people are without power in Texas, according to the PowerOutage.US website, which tracks outages across the US. There are over 93,000 people without power in Louisiana, which is still recovering from Hurricane Ida's mass devastation.
The governors of both Texas and Louisiana have issued states of emergency.