Heatwave and Smoky Skies to Persist in Inland Northwest Washington Before Cooler Change

Today's weather will be dominated by high pressure, allowing temperatures to rise near or slightly above Friday's levels.Photo byAndrey GrinkevichonUnsplash

The Inland Northwest is bracing for another scorching weekend as high temperatures are expected to remain in the 90s through Sunday. Cities such as Lewiston, Moses Lake, Omak, and Leavenworth could flirt with the 100-degree mark today, driven by a persistent ridge of high pressure. However, the heat will be accompanied by worsening air quality due to wildfire smoke spreading from Oregon and Central Idaho.

Today's weather will be dominated by high pressure, allowing temperatures to rise near or slightly above Friday's levels. The significant factor impacting temperature potential will be the haze and smoke, which may block some solar radiation and keep temperatures from reaching their highest possible values. Light northeast winds are anticipated throughout the day.

Looking ahead to Sunday, a shortwave trough currently off the California and Oregon coast will begin to influence the weather. This trough will bring increased cloud cover and potentially thicker haze or smoke as it moves northeast into the Inland Northwest. The resulting changes in the air mass are expected to lower high temperatures slightly. The region will also experience some moisture, leading to a modest chance of thunderstorms, particularly in the Cascades and southeastern Washington, as well as north-central Idaho. While thunderstorms are possible, the chance for lightning is relatively low, and rainfall amounts are expected to be minimal.

Winds will shift from light northeast to breezy southerly conditions, with gusts up to 25 mph near any showers or thunderstorms. The Blue Mountains may see gusts reaching 30 mph or higher. As the ridge breaks down in the evening, cooler air will start to flow into the region.

The forecast for next week shows a significant pattern change with a trough expected to arrive in the Pacific Northwest by Tuesday and Wednesday. This shift will bring cooler temperatures, dropping roughly 5 degrees each day from Monday through Wednesday. Breezy conditions are likely, with sustained winds of 15 mph or more becoming more common. The combination of high temperatures in the 80s to low 90s and low humidity could create elevated fire weather conditions, although it remains uncertain if red flag warnings will be issued.