A dry and stable upper level ridge of high pressure is building over the Pacific Northwest today and will persist through the weekend and will become pinched between an upper level trough and a closed area of low pressure off the coast. This will lead to a dry and warming period for the next two days as the upper ridge holds the dominant influence over the weekend…followed by a stabilization or slight moderation of temperatures on Monday. No precipitation and only minimal clouds are expected during this period.
Weather for today calling for sunny skies, light winds and warmer temperatures with highs in the mid to upper 70’s.
As we get tot the weekend tomorrow the high-pressure ridge intensifies bringing Northcentral Washington mostly sunny to sunny skies along with unseasonably warm temperatures with highs on both Saturday and Sunday in the upper 70’s to lower 80’s. However, on Sunday a strong easterly surface pressure gradient will form over the eastern part of our forecast area with northeast winds becoming noticeably breezy late Saturday and then really charging up into the solidly windy and gusty category on Sunday through Monday mid-day or so before the gradient begins to relax. The Columbia Basin east of the Waterville Plateau will be subject to 15 to 30 mph sustained winds with gusts in the 35 to 40 mph range on both Sunday and Monday.
On Monday the offshore closed low will begin to take a dominant weather role as it encroaches on the Oregon coast…flattens the ridge and forces the axis east through the forecast area. This will open the door for moist southerly flow to begin spreading thickening high clouds into the area Monday with high temperatures in the mid to upper 70’s.
By Tuesday the offshore low drifts even closer to the coast and allows the moisture to push toward the Canadian border. Despite the northward push, most of the deep instability will remain fixed over the far southeast portions of the forecast area for another chance of afternoon/evening thunderstorms.
Meanwhile the increased moisture will result in a decent chance of showers for most locations. Northcentral Washington can expect mostly cloudy skies both Tuesday and Wednesday with a 40% chance of showers on Wednesday and a 20% chance of scattered showers on Thursday with afternoon high temperatures both days near 70 degrees.