A large low pressure trough is positioned over the northwest U.S., Western Canada, and the waters off the northeast Pacific and will continue to influence our weather. The potent shortwave that moved through the region Monday is already in Saskatchewan.
The next strong shortwave is out over the Pacific waters but is strengthening and moving quickly around the base of the trough. That storm system will bring the Inland Northwest the next round of valley rain and mountain snow later today, tonight and into Wednesday.
A Winter Storm Warning will go into effect at 4:00 p.m. today to 4:00 p.m. on Wednesday for areas above 3000 feet in Chelan and Okanogan counties. That means passes including Snoqualmie, Stevens, Loup Loup, and Blewett could see around 8-12 inches of snow. A break in the active weather pattern is expected Friday and Saturday before precipitation chances increase again Saturday night and especially on Sunday.