Repeating and slow-moving storms will raise the risk of flash flooding and damaging winds over northern and central High Plains into Thursday night.
A combination of moisture streaming northward and very warm air in place will produce rounds of showers and thunderstorms in a swath from southeastern Montana to southwestern South Dakota, eastern Wyoming, eastern Colorado, Nebraska and Kansas.
Motorists traveling along area highways, including interstates 25, 70, 80 and 90, should be on the lookout for rapidly changing weather conditions.
"The most likely threats from these storms will be large hail and damaging winds," according to AccuWeather Meteorologist Becky Elliott.
"An isolated tornado cannot be ruled out, mainly in far northeastern Colorado and western Nebraska," Elliott said.
Cities that could be affected by severe thunderstorms include Miles City, Montana; Cheyenne, Wyoming; Rapid City, South Dakota; North Platte, Nebraska; Garden City, Kansas; and Denver.
While much of the High Plains is in need of gentle, soaking rainfall at this point of the summer, too much rain may fall too fast and result in flash flooding in some locations.
"As the storm complexes push eastward during the overnight hours, heavy rainfall and flash flooding is most likely across portions of the central Plains," Elliott said.