Morning sunshine will give way to bands of high clouds this afternoon as a weak weather system moves into British Columbia. High temperatures are expected to generally be in the 70s across the Inland Northwest with a few spots like Moses Lake and Wenatchee flirting with 80 degrees. Pre-frontal south winds this afternoon are expected to be between 10-15 mph across much of eastern Washington and far north Idaho. Gusts of 20 mph or more will be possible late in the afternoon up the Okanogan Valley and over the Waterville Plateau. Look for a wind shift early this evening as the front spreads across the Cascades. West winds gusting to 25 mph are expected through sunset in Wenatchee, Chelan, Vantage, and Waterville.
For both Wednesday and Thursday, under mostly sunny skies, afternoon temperatures will again reach the upper 70’s with some communities like Lewiston, Moses Lake, Wenatchee, and Omak near 80 degrees. Look for westerly gap winds Wednesday night in the lee of the Cascades that could blow between 10 and 20 mph around Wenatchee, Chelan, and Vantage.
By Friday, the ridge of high pressure that’s been in place shifts just slightly to the east allowing some instability to move in bringing Northcentral Washington a 30% chance for evening showers with afternoon high temperatures near 80 degrees.
Saturday through Monday, weather model agreement is quite good that an offshore low-pressure system will shift into Western Washington on Saturday and then over eastern Washington on Sunday and Monday. This will bring a much wetter and cooler weather pattern to the Inland Northwest as a strong cold front also pushes through the region on Saturday. The front will obviously deliver much cooler temperatures, and it will probably bring breezy conditions on Sunday as well. Highs on Saturday will be in the upper 60’s to lower 70’s with a 40% chance of scattered showers. The temperatures will cool even further for Sunday and Monday with highs in the upper 60’s to near 70 degrees. There is also a 30% chance of showers o Sunday going down to a 20% chance of mainly isolated showers on Monday.