15 Apr 2021 | 02:11 PM UTC
US: Adverse weather forecast across some southern regions through at least early April 18 /update 3
Heavy rainfall, strong winds, and possible flooding forecast across southern US through at least April 18. Disruptions possible.
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 April 18. The affected area includes central and eastern Texas, far southwestern and far southeastern Oklahoma, southern Arkansas, Louisiana, western and southern and central Mississippi, southern Alabama, far southern Georgia, and northern Florida. The Storm Prediction Center (SPC) has issued a "Slight Risk" (Level 2 on a 5-tier scale) for severe weather for portions of central Texas. 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. Officials could update and possibly extend the coverage of the relevant weather alerts over the coming days.
Heavy rainfall and flooding will be the main threat for the southern US. As a result, the Weather Prediction Center (WPC) has issued a "Slight Risk" for excessive rainfall for Louisiana, southern Mississippi, and far southwestern Alabama, where the heaviest rainfall is forecast. Officials could update and possibly extend the coverage of the relevant weather alerts over the coming days.
Government Advisories
As of April 15, officials with the National Weather Service (NWS) have maintained flood and flash flood watches and warnings for southern Louisiana, far southern Mississippi, far southwestern Alabama, and the far western Florida Panhandle. Officials could update and possibly extend the coverage of weather alerts over the coming days.
Hazardous Conditions
The storms will be capable of producing heavy downpours and damaging winds across the affected area through at least early April 18. 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 or landslides 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, including the I-10, 1-20, I-35, I-49, and I-65 corridors. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.
Severe weather could also trigger flight delays and cancellations at regional airports. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas that see heavy rainfall and potential track inundation. Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and some employees' inability to reach work sites.
Advice
Monitor local media for weather updates and related advisories. 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.
