A Ridge of high pressure will hold its grip over the Inland Northwest for most of the day today which will prevent deeper level moisture from pushing east of the Cascades. A lot of high clouds, but not enough moisture for precipitation for Northcentral Washington today, expect light winds with afternoon high temperatures in the mid to upper 30’s. Fog in the valleys is patchy.
Tonight through Tuesday, a tightly wound low pressure system will move into the inland northwest. Timing of the weather front is an important detail as it will make all the difference with precipitation type and whether or not there is accumulating snow, at least on the roads. Timing in the lee of the Cascades into the western basin and Okanogan Highlands will be early in the morning on Tuesday. Temperature profiles support snowfall over much of this area with up to half an inch possible at Moses Lake and Ephrata, around an inch for Wenatchee and up to 2 inches for Omak and Republic. The added orographics will squeeze out a little bit more snow for places like Leavenworth, Plain and the Methow Valley with between 2 to 4 inches for the morning hours.
For Wednesday into the upcoming weekend, expect mild and unsettled weather. The Columbia Basin, Methow Valley and the Wenatchee Valley can expect cloudy skies each day with anywhere from a 30-50% chance of mainly rain showers with afternoon high temperatures unseasonably mild into the lower and mid 50’s with overnight lows in the lower to mid 30’s.