Sat imgry seems to confirm 18Z GFS (though it may be a bit heavy handed). Warmth aloft will have a hard time moving N of Seatac. Most models continue to appear initially 2-4 deg warm. Sat imgry shows little development. N of the red line on the sat img, watch out. #wawx pic.twitter.com/LEbpgpeQuy

— NWWashingtonWX (@wx_washington) December 19, 2022