US: Adverse weather forecast across the southern and central regions through at least early April 29 /update 1

Severe weather is forecast across parts of the South, Ohio Valley, and Upper Midwest regions through at least early April 29. Several rounds of severe storms are forecast across the affected area over the coming days, with the peak of the severe weather likely April 26-27. Heavy rainfall, 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 April 26, the US National Weather Service (NWS) has issued flash flood warnings for parts of southeastern Kansas and southwestern Missouri and flood warnings across scattered parts of eastern Texas, southern Arkansas, northern Louisiana, and west-central Illinois. A tornado watch is in place for parts of eastern Oklahoma and severe thunderstorm warnings and watches for parts of eastern and southern Oklahoma. 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) over parts of northeastern Kansas, eastern Nebraska, northwestern Missouri, and central, southern, and western Iowa April 26-27. There is a slight risk of severe storms for surrounding areas from northeastern Texas northward to far southeastern South Dakota and northern Iowa April 26-27. There is a further enhanced risk of severe thunderstorms from northern Texas through central Oklahoma and central and eastern Kansas into southeastern Nebraska, northwestern Missouri, and southwestern Iowa April 27-28 and a slight risk for areas from south-central Texas northeast-eastward to the Upper Michigan Peninsula. There is a further slight risk of severe thunderstorms from northeastern Texas northward to southern Iowa April 28-29.

The NWS's Weather Prediction Center has warned of a slight risk of excessive rainfall (the second lowest level on a four-tier scale) from northeastern Texas north-northeastward to central Missouri April 26-27. There is a moderate risk of excessive rainfall from northern Texas across central and east-central Oklahoma into southeastern Kansas April 27-28 and a slight risk for surrounding areas from central Texas north-northeastward to southern Iowa. There is a further risk of excessive rainfall for northeastern Texas, eastern Oklahoma, northwestern Louisiana, much of Arkansas, and southern Missouri April 28-29.

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 possible where significant flooding or landslides impact utility networks.

The severe weather could 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 may 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 possible in areas with heavy rainfall and potential track inundation.

Localized business disruptions will probably 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.