US: Adverse weather forecast across the South, Southeast, and Ohio Valley regions through at least early March 17

Severe weather is forecast across parts of the South, Southeast, and Ohio Valley regions through at least early March 17. A storm system is forecast to bring heavy rainfall and thunderstorms. Strong winds, lightning, hail, and possible tornadoes may accompany storms. Heavy downpours may trigger flooding in low-lying areas, and strong winds may cause property damage and power outages.

As of late March 12, the US National Weather Service (NWS) has not yet issued any flood or flash flood watches and warnings. Authorities will likely issue new alerts as weather conditions change over the coming days.

The NWS's Storm Prediction Center has warned of an enhanced risk of severe thunderstorms (the middle level on a five-tier scale) from southeastern Oklahoma into western Arizona and far southwestern Missouri March 14. A slight risk of severe thunderstorms is in place across parts of the Central Plains and lower Missouri Valley March 13 and from northeastern Texas northeastwards into southeastern Iowa, northern Illinois, and southwestern Indiana March 14.

The NWS's Weather Prediction Center has forecast a slight risk of excessive rainfall (the second lowest level on a four-tier scale) from northeastern Texas northeastwards into far southeastern Missouri and southwestern Tennessee March 14, from eastern Texas eastwards into southeastern Tennesse and far southwestern North Carolina March 15, and from eastern Texas eastwards into central Alabama March 16-early March 17.

Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed 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 heavy rainfall has saturated the soil. 

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are likely where significant flooding or landslides impact utility networks.

The severe weather will likely contribute to transport disruptions throughout the region. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities will probably temporarily close low-lying routes that become inundated by floodwaters.

Severe weather will likely cause flight delays and cancellations at airports across the affected region. Flooding could block regional rail lines; freight and passenger train delays and cancellations are probable in areas with heavy rainfall and potential track inundation.

Localized business disruptions will likely occur in flood- or tornado-hit areas; some businesses might not operate at full capacity because of damage to facilities, possible evacuations, and some employees' inability to reach work sites.