WSDOT is warning motorists that all of Washington's major mountain passes will likely remain closed Friday and won't reopen until Sunday.

Communications Manager Lauren Loebsack said Blewett, Snoqualmie, Stevens and White Pass will all remain closed at least through Thursday.

"While there have perhaps been occasions overnight where they were all closed in the middle of the night momentarily, a lengthy closure of all of these passes is quite unusual," stated Loebsack.

WSDOT's avalanche control teams also had to be pulled from their work Thursday because of the threat of slides.

Loebsack said, "In Tumwater Canyon alone we had 50 snow slides, two of which trapped a plow driver this morning."

35 inches of new snow was reported on Blewett Pass Thursday morning. Loebsack said crews have never seen so much snow in one day before in the area.

More From NewsRadio 560 KPQ