(NewsNation) —  The Omaha, Nebraska area has been hit by a monster storm that’s spawned tornadoes, baseball-sized hail and torrential rain, and caused what some spotters call “massive damage.” Authorities there, and across the Missouri river in Iowa, have declared tornado emergencies.

Spotters have already noted more than two dozen tornadoes in eastern Nebraska. One especially huge, nearly black twister near Waverly crossed Interstate 80, forcing drivers to pull off the road before encountering the winds.

Several counties posted tornado warnings and watches throughout the afternoon. Pictures posted to Rural Radio’s website showed several other twisters, as well as damage to homes and other buildings. Other photos on The Weather Channel site show homes completely destroyed.

Omaha TV stations, including KVET, are covering the event.

Tornado warning sirens were heard throughout the city of Omaha at around 5pm CT. Local media report thousands around Omaha are without power. Authorities in Nebraska and nearby western Iowa are warning people to seek shelter.

Tornado watches are also up for the many counties between Kansas City, Missouri, and Des Moines, Iowa.

The National Weather Service defines a tornado emergency as an event that causes significant, widespread damage with a high likelihood of numerous fatalities. NWS is posting updates on its X page.

This is a developing story. Check back for updates.