(CNN) Gov. Roy Cooper will declare a state of emergency Wednesday for the western part of North Carolina, the governor's office said in a statement.

The announcement follows heavy rains that slammed the mountainous area Tuesday and Wednesday, causing mudslides and forcing evacuations and road closures -- including a portion of Interstate 40. "Our emergency response and transportation crews have been working through the night to keep North Carolinians safe as conditions deteriorate," Cooper said.

" ... this storm isn't yet over. I'm urging people to keep a close eye on forecasts and flood watches, and asking drivers to use caution especially when traveling in our western counties."

The emergency declaration will help the state coordinate its response and "prepare for any additional impacts," the statement said.

In the last 24 hours, 4 to 7 inches of rain slammed parts of a region that had been hit by frequent rain for a couple of weeks. And in the next couple of days, there will be a threat of flash flooding as storms persist, the governor's office said.