US: Adverse weather forecast across central and northern regions through at least early Sept. 18

Severe weather is forecast across parts of the northern and central US through at least early Sept. 18. A low-pressure system emerging from the Rockies Sept. 17 is expected to bring showers and some severe storms across parts of the northern and central plains. 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. 17, the US National Weather Service (NWS) Storm Prediction Center has warned of an enhanced risk of severe thunderstorms (the middle level on a five-tier scale) across parts of northeastern Colorado, western Nebraska, and far northwestern Kansas through early Sept. 18. There is a slight risk of severe thunderstorms across the rest of the affected area.

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.