Soaking rain, snow and a blast of cold air is heading for the Northwest on Sunday and into this week.
Snow levels on Sunday will start out above pass level in the Washington Cascades.
However, rain can be heavy at times in the foothills and passes with the risk for flooding in low-lying and poor drainage areas. Some rivers and streams can fill and overflow their banks from runoff.
The flood threat and reduced visibility during bouts of heavy rain can cause delays on the roads, including I-90 though Snoqualmie Pass.
Snow levels on Sunday night will fall to pass level and there can enough accumulation to create slippery roads.
Gusty winds over 30 mph will also accompany this storm, which can snap off smaller branches and perhaps cause localized power outages.
By late on Monday into Monday night, snow levels will fall below 1,000 feet across western Washington southward into western Oregon.
Seattle and the surrounding lowlands can get snow showers mixed with rain showers late on Monday and Portland, Ore., can have a snow shower on Monday night.
Snow levels will start out at 5,000 to 6,000 feet on Sunday in the northern Rockies, then fall on Sunday night into Monday as colder air arrives, getting down to the valley floors across Idaho and Montana by Monday morning.
Snow will be heavy at times through Monday night, and the heavy snowfall rates will significantly reduce visibility and cause roads to become snowpacked and treacherous.
Gusty winds will create blowing and drifting, making driving conditions even more hazardous.
Travel across I-90 from northern Idaho into Montana and I-15 in western Montana will become increasingly difficult as the snow starts to pile up.
Temperatures across portions of the Northwest will be abnormally cold this week.
Several locations, including Seattle and Portland, will flirt with their record low temperatures at times this week.
For the middle and latter portions of this week, AccuWeather.com meteorologists are forecasting temperatures 20 to 35 degrees below normal for some locations in Idaho, Montana and Wyoming.
There could be numerous record low temperatures either tied or broken, as some locations will plummet to 20 below zero or colder.
The risk of flooding downpours and gusty thunderstorms will increase across southern Florida as a tropical disturbance shifts northwestward from Cuba this weekend.
Slow-moving and repetitive downpours will raise the risk for flash flooding along the western Gulf Coast into early next week.
Stargazers will want to dig out their binoculars and telescopes this weekend as Venus and Jupiter shine so close that they appear as one large, bright star in the evening sky.
Typhoon Lionrock is poised to make landfall in Japan early in the new week with heavy rainfall, damaging winds and an inundating storm surge.
Hawaii is facing not one, but two tropical threats next week as Madeline and Lester churn westward.
Hot and dry weather will greet fans and competitors at the 2016 U.S. Open Tennis Championships in Flushing, New York, as play begins Monday, Aug. 29.
The Bronx, NY (1990)
Strong thunderstorms dumped 4.24 inches of rain.
Nassau, NY (1990)
Thunderstorm winds overturned boat, injuring 12.
Mt. Washington, NH (1856)
A total of 3 inches of snow on peak of mountain.