US: Adverse weather forecast across eastern regions through at least Sept. 29

Severe weather is forecast across parts of the eastern US through at least Sept. 29. Heavy rainfall and thunderstorms fuelled by tropical moisture from former Hurricane Helene are expected across parts of the Tenessee Valley, Ohio Valley, and southern Mid-Atlanitc regions. Strong winds, lightning, hail, and tornadoes may accompany storms. Heavy downpours could trigger flooding in low-lying areas and strong winds may cause property damage and power outages.

As of early Sept. 27, the National Weather Service (NWS) has issued flash flood warnings, tornado watches, flood warnings, watches, and advisories, and high wind warnings and advisories across parts of the affected area.

The NWS's Weather Prediction Center has warned of a high risk of excessive rainfall (the highest level on a four-tier scale) across parts of western North Carolina Sept. 27-28, as well as a moderate risk for parts of western North Carolina, west-central Tennessee, far southeastern Kentucky, and southwestern Virginia and a slight risk across much of rest of the affected area. A slight risk of excessive rainfall remains across parts of north-central Kentucky, southern Indiana, and far southwestern Ohio Sept. 28-29.

The NWS's Storm Prediction Center has warned of an enhanced risk of severe thunderstorms (the middle level on a five-tier scale) across coastal and adjacent inland areas of North Carolina and South Carolina Sept. 28-29. There is a slight risk of severe thunderstorms across much of the rest of North Carolina and parts of southern Virginia.

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. Disruptions to electricity and telecommunications services are possible where significant flooding or strong winds impact utility networks.

The severe weather could contribute to transport disruptions throughout the region. Traffic and commercial trucking delays might occur along regional highways. Flooding downpours could inundate some low-lying roads in areas with poor drainage. Strong winds might also pose a hazard to high-profile vehicles. Hazardous weather conditions might cause flight delays and cancellations at airports in the region.

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.