weatherblog

Street flooding likely in storminess this weekend

This first bout of fall storminess will being several types of impacts to the Northwest tonight through the weekend. None of them will be major problems for most, but heavy rain combined with leaves coming off our trees will cause storm drains and urban/street flooding at times.

The start of the rain is this evening around Puget Sound.

A Wind Advisory is in effect for the coast and north/west of Everett where winds could top 40 mph in gusts.

For the rest of us -- including Puget Sound -- the wind gusts this evening into tomorrow are likely to be in the 15-30mph range.  It’s not a big deal in terms of actual wind speed but will be enough to hasten the fall of leaves, which begets more street flooding. Rain will likely not be as constant on Saturday but with passing downpours, we will pick up more than an inch of rain in most lowland spots between tonight and tomorrow night.

Thunderstorms will also be possible tomorrow as the atmosphere will be modestly unstable.

In the mountains, the snow levels will have fallen to about 5,000 feet by late Saturday into Sunday bringing some snow to the higher peaks. We’ll probably see new snow at Paradise on Mount Rainier (5,400 feet) but likely no issues down on U.S. 2 at Stevens Pass (4,000 feet). Perhaps some wet snow could mix in there but no accumulation. Snoqualmie Pass will be all rain.

On Sunday, it looks like we could have a brief lull during the morning, but then more heavy rain arrives by afternoon stretching into Sunday night.

Monday will bring scattered showers but a relative break before another quick-hitting weather system moves through on Tuesday into Wednesday. By then, lowland spots will have received an average of 2-3 inches of rain with the mountains (below the snow level) getting 4-8 inches. This will push our rivers higher but probably no flooding of area rivers.