A persistent flow of air coming off of the Pacific Ocean will support a bout of cool and showery weather for Portland and surrounding communities into the weekend.
A large dip in the jet stream has formed over the Northwest and in the north Pacific Ocean and this pattern will continue to send moisture and cool conditions onshore into early next week.
A cold front will move through the region tonight, which coincides with the time period of heaviest rainfall. By Saturday, the front will move into the northern Rockies and cooler air will descend on the Pacific Northwest. Temperatures across the Portland metro area will struggle to get into the middle 50s on Saturday with overcast skies and scattered showers.
Slight improvement is expected on Sunday as showers become less widespread, but the onshore flow will keep things rather cloudy and cool.
The aforementioned dip in the jet stream will keep clouds and chilly showers around through at least Monday.
In fact, the air will become so cool aloft that snow will fall down to pass level in the Washington Cascades. This will bring the first significant snow to both Stevens and Snoqualmie passes.
Some snow will even fall in the Oregon Cascades with snow levels dropping to about 4,500 feet on Saturday.
Severe thunderstorms with the risk of a few tornadoes will advance eastward across the northern Plains and Upper Midwest into Friday.
A dangerous outbreak of severe storms will strike the northern High Plains and Canadian Prairies on Wednesday.
Join us on Thursday for AccuWeather LIVE as we will discuss the debate of climate change and hurricane frequency and the top five things you need to know about summer weather.
A hot and humid weekend is shaping up for Chicagoland just in time for the official start of summer, while severe thunderstorms fire nearby to the north.
A tornado touched down at Denver International Airport as a severe weather system moved through the area.
A brief synopsis of the top five worst weather events of last summer.
3-4" rains common across the state.
New Brunswick, NJ (1835)
Great New Brunswick Tornado; 5 dead, 17-mile path through the center of town; in all, 145 buildings were damaged. This is the worst tornado catastrophe in New Jersey history to date.
Central Illinois (1964)
19th-20th) Hail as large as grapefruits battered more than 50 counties, causing crop and property damage totalling $9.2 million.