Dry weather will be hard to find next week across the Northwest
The jet stream will be more "flat" this week and oriented towards the Northwest U.S. as opposed to the "wavy" north to south pattern that we've recently seen. This will steer moisture and storm systems persistently into the Northwest through Thursday and keep temperatures lower than normal.
A strong "flat" jet stream will send moisture and storm system persistently into the Northwest U.S. through early next week. Shown are 250 mb wind speeds from the 12Z Fri. GFS model.
So for places like Seattle, Portland, Boise and Spokane, it may be wise to have an umbrella as there will be plenty of chances for rain and showers through the week. The highest chance for heavier rain will be early Monday and again early Tuesday as two systems pass through. Next week will also end up cooler than normal thanks to the rain and clouds.
While the jet stream remains north, most of California (except for far northern California) will stay dry through the week and will still continue to run above-normal with temperatures.
A flat upper-level ridge will help promote warm weather and keep storm systems from pushing south.
A "flat" 500 mb ridge over California and the Southwest will keep storm systems form pushing south. Meanwhile, below-normal 500 mb heights will lead to stormy and cool weather across the Northwest through the middle of next week. Shown is 500 mb height anomalies from the 12 Fri. GEFS.
Weather models towards the end of the week suggest that the pattern will change a bit, with a 500 mb ridge developing off the West Coast over the Pacific Ocean and a deep trough developing over the Intermountain West. This will shift most of the unsettled weather and cooler air to this area and away from the Northwest.
Models suggest that a 500 mb trough will be focused over the Intermountain West over the weekend and early next. This is where the cool and unsettled weather will shift. Shown is 500 mb height anomalies from the 12 Fri. GEFS for next weekend into the following week.
