(NewsNation) — The rain and snow in California has died down, but other parts of the country should prepare for freezing rain, snow and threats of tornadoes and flash flooding in some areas.

A potent storm is strengthening in the Rockies, with periods of snow forecast across the Intermountain West. Intense rain is also possible late Monday and early Tuesday. It could lead to isolated instances of flash flooding, and possible excessive rainfall from southern Kansas through western Oklahoma and northwest Texas, according to the National Weather Service.

Heavy snowfall will begin Monday evening and persist throughout Tuesday for the central and northern high planes. The eastern portions of North and South Dakota are also slated to receive freezing rain, which could move into southwest Minnesota and northwestern Iowa, NWS meteorologist Rich Otto said.

“The max that we’re looking at right now could be a quarter-inch to even a half-inch of freezing rain accumulation,” Otto said.

Travelers should take extra caution as strong winds and widespread blizzard watches and warnings move throughout the central and high planes.

“Today is probably the last day to really prepare and grab extra winter supplies (to have) on hand,” Otto said Monday.

The system will persist throughout the week, bringing waves of severe weather farther east, affecting the Carolinas on Wednesday and Thursday and possibly affecting the Northeast into the weekend.

The greatest risk of heavy rainfall along with tornadoes, wind and hail in Eastern Texas and into Louisiana and Mississippi Valley will begin Tuesday and continue through Wednesday.

The Associated Press contributed to this report.