Thunderstorm Forecast Update: Strong to Severe Thunderstorms May Bring 'Excessive Rainfall' to Southern US on Saturday [NWS]

Thunderstorms are expected to impact the southern United States this weekend, causing multiple weather hazards that can cause widespread disruption, infrastructural damage, and life-threatening risks. In its thunderstorm forecast update, the National Weather Service (NWS) warned that strong to severe thunderstorms may bring "excessive rainfall" to the South US on Saturday, April 20.

The main threats posed by the looming storm system across the US region are damaging winds and large hail, as well as the potential occurrence of a tornado outbreak. For the past several weeks, severe thunderstorms have rampaged in different parts of the country, including in the Midwest, Central US, and the Southeast US. Some of these storms spawned several deadly tornadoes.

Thunderstorm Forecast Update

The most evident risk from the latest thunderstorm forecast update is the threat of flooding from the excessive rainfall being anticipated by US meteorologists this weekend. In its short-range forecast at 3:29 a.m. EDT (local time) on Saturday, the NWS' Weather Prediction Center (WPC) stated heavy rain and flash flooding events are possible across the southern Plains and lower Mississippi Valley.

The WPC explains that a "quasi-stationary front" hovering over the Southeast US, Gulf Coast, and southern Plains will be responsible for multiple showers and thunderstorms this weekend. The most affected areas of heavy rain events, with potential flash flooding risk, will be in areas from Texas to Mississippi. Northern Louisiana and southern Arkansas are included in these areas as well.

In its previous forecast earlier this week, the NWS on Friday, April 19, also warned of severe weather or a stormy weather event for the Southeast this weekend, where it forecasted for scattered showers and thunderstorms across the region. The current weather system over the region follows a deadly tornado outbreak earlier this month, where multiple people died across the Gulf Coast states.

Concerning the current severe weather system, the US Government weather agency on Saturday added that heavy rain from the thunderstorms may lead to isolated flash flooding and urban flooding. These potential risks may coincide with the overflow of rivers and streams across East Texas and the lower Mississippi Valley.

Potential Thunderstorm Threats

Previous thunderstorms in the US not only caused power outages, flooding, and weather-related deaths but also travel disruptions. In 2023, thunderstorms that slammed the Northeast US led to the cancelations and delays of thousands of flights nationwide, including domestic and international flights. Based on this year's forecasts, potentially disruptive thunderstorms are still possible.

In its 2024 US Spring Outlook in March 2024, the National Oceanic and Atmospheric Administration (NOAA) forecasted a warmer weather for most parts of the US, but a wetter weather in the Southeast US. Also, the majority of Continental US and Alaska will experience above-average temperatures from April to June this year, according to the NOAA.