30 Apr 2021 | 02:26 PM UTC
US: Adverse weather forecast across the southern regions through at least early May 4 /update 2
Heavy rainfall, strong winds, hail, and possible flooding forecast across southern US through at least early May 4.
Event
Thunderstorms with rounds of heavy rainfall, strong winds, and possible flooding are forecast to occur across portions of the southern US through at least early May 4. The affected area includes central, eastern, and southern Texas, central and eastern Oklahoma, far southeastern Kansas, Louisiana, Arkansas, far southwestern Missouri, Mississippi, western Alabama, and southwestern Tennessee.
The Storm Prediction Center (SPC) has issued a "Slight Risk" (Level 2 on a 5-tier scale) forecast for severe weather for far eastern Texas, eastern and southern Louisiana, far southeastern Arkansas, Mississippi, and far southwestern Tennessee May 2-early May 3. However, storms in this region are not forecast to be widespread or long-lived. Isolated intense storms are possible, which may contain hail, damaging winds, and a few tornadoes.
Heavy rainfall and flooding will be the main threat for the Southeast. As a result, the Weather Prediction Center (WPC) has issued a "Moderate Risk" for excessive rainfall for portions of southeastern Texas, where the heaviest rainfall is forecast. Additionally, officials have issued a "Slight Risk" for excessive rainfall for southern Texas. Officials could update and possibly extend the coverage of the relevant weather alerts over the coming day.
Government Advisories
As of April 30, officials with the National Weather Service have issued flood watches and warnings are in effect across portions of southeastern Texas and far southern Mississippi. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.
Hazardous Conditions
The storms will be capable of producing heavy downpours, damaging winds, hail, and tornadoes across the affected area through at least early May 4. Should sustained heavy rainfall occur, it could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed or a lack of stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where the soil has become saturated by heavy rainfall. Disruptions to electricity and telecommunications services are possible where significant flooding, landslides, or strong winds impact utility networks.
Transport
Floodwaters and debris flows could render some bridges, rail networks, or roadways impassable, impacting overland travel around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.
Severe weather could also trigger intermittent flight delays and cancellations at regional airports, though these are unlikely to be severe or prolonged. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track inundation. Localized business disruptions may occur in low-lying areas.
Advice
Monitor local media for weather updates and related advisories. Out of an abundance of caution, confirm all transport reservations and business appointments before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.
