A Tropical Area of Low Pressure Threatens the Already Flooded Gulf Coast

Written by Sarrah Pelorus

Last updated 5/21/2021, 6:09:40 PM

In the Gulf of Mexico, a tropical area of low pressure is being watched for possible development. This system could bring even more heavy rainfall to already saturated areas of Texas and Louisiana into this weekend.

 The surface circulation has formed in the western Gulf of Mexico just over 150 miles east of the South Texas coast. Which meteorologists are referring to as Invest 91L, a term used to identify systems that could potentially develop into a depression or storm. Currently, shower and thunderstorm activity near Invest 91L remains rather weak, partially due to a bout of dry air that has surrounded the system from a swirling upper-level low that spawned the surface low. If more thunderstorms and showers develop near the low-pressure center, a short-lived tropical depression or tropical storm could form before it moves inland over the Texas Gulf Coast tonight.

The biggest threats from this system thus far remain rainfall, tropical storm watches or warnings that could be issued later today. The National Hurricane Center has assigned a medium risk of development of this system on Friday. The threat of more heavy rain and possible flooding will be highest from eastern Texas into southern Louisiana. Flood watches have been issued by the National Weather Service for parts of those states. This includes Baton Rouge, Beaumont, Lake Charles, New Orleans and Shreveport. The biggest threat right now is flash flooding, especially in areas that have already been hard hit. Officials have ushered caution to residents recommending citizens to not attempt to drive through a flooded road if you encounter one and avoid travel at all if possible. The worst decision you can make in a flash flood is driving your vehicle into floodwaters of unknown depth. 

Many river gauges in southeast Texas and Louisiana have already risen above major flood stage because of this week's rainfall. The areas that are currently under flood watches could see at least an inch of additional rainfall. Heavier totals are likely where heavy rain stalls out for hours at a time, but it's not possible to pinpoint exact locations where that might happen at this time.

This system comes towards the south after a week of deadly flooding. Earlier in the week beginning Monday, a cluster of thunderstorms stalled over parts of southeast Texas and southwest Louisiana on Monday, with up to 18 inches of rain. The intense flooding prompted the National Weather Service to issue a rare flash flood emergency Monday night for the city of Lake Charles and surrounding areas of Calcasieu and Jefferson Davis parishes.

Numerous homes and buildings, including a church and a diner, took on water in Lake Charles, Louisiana, according to the National Weather Service. Vehicles were flooded up to the roofs in some areas. The rain was record breaking as Lake Charles Airport measured over 12 inches of rain Monday alone, which is the city's heaviest calendar-day rain in 41 years and also more rain that was received during both Hurricanes Laura and Delta in 2020. The flooding was relatively widespread as a flash flood emergency was also issued in western Jefferson County, Texas, where water was also reportedly entering homes in Fannett, Texas. (about 65 miles east-northeast of downtown Houston.) According to the National Weather Service, Interstate 10 reported flooding between Beaumont and Hamshire, Texas, as well.

The flash flooding was also reported in Port Arthur, Texas, in Jasper County, Texas, and parts of the north and east sides of the Houston metro area near Aldine, Baytown, Conroe and Humble. The National Weather Service also issued another flash flood emergency for the southeast Baton Rouge, Louisiana, area overnight Monday night, where up to a 12 inches of rainfall was recorded. The flooding prompted water rescues and covered a portion of Interstate 10 to the southeast of the city. The rain continued into Tuesday, a significant flash flooding impacted at least four homes and eight cars in Saline County, Arkansas, or just southwest of Little Rock. A total of 15 people had to be rescued because of flooding in the county.

Other flooding Tuesday or Tuesday night took place on the west and north sides of the Houston metro, as well as in Victoria and Port Lavaca. Victoria's over 16 inches of rain this month is not only a record for May, but is also a top five record wet month dating to 1946. The storms continued later into the week with parts of coastal and Deep South Texas receiving more flooding into Wednesday and Thursday. Streets were closed off in the Corpus Christi metro area for flooding as water reportedly entered businesses near Corpus Christi International Airport. In Nueces County up to 8 inches of rain was reported by the National Weather Service. The Lower Rio Grande Valley also was drenched by 3 to 5 inches of rain Wednesday. The flooding stretched to Kingsville, Laredo and Palacios, Texas where high water forced the shutdown of a four-mile stretch of Interstate 10 west of Sealy, Texas. Thursday brought even more heavy storms over the Baton Rouge metro area, renewing flooding in parts of East Baton Rouge and Ascension Parishes. Roads were closed in several locations, including near Baton Rouge Metro Airport.

The weather this week alone has been incredibly active. Stay ahead of the storms with WeatherTAP.com! Start your free trial today with no credit card information required at sign-up.