A potent front brought heavy rains to the region Wednesday morning, causing a number of traffic backups and dozens of accidents Wednesday morning.
It was only the beginning.
While the rain let up toward mid-morning and the sun could even be found peeking through the clouds, a second, stronger storm was racing toward the region, due in just after the evening commute finishes for another round of heavy rains and blustery winds.
Seattle received 1.37 inches of rain since Tuesday evening -- 1.22 inches of that since midnight. Volunteer weather spotters with the CoCoRahs.org reported 24-hour rain storm totals well over an inch across the Puget Sound region -- with some spots reaching over 2 inches.
The heavy rains are putting pressure on our area river, and Flood Watches are up on all mountain-fed rivers in Western Washington, meaning there is potential for flooding. The exception was a Flood Warning was issued for the Skokomish River in Mason County meaning flooding was imminent. River forecasters just expect minor flooding.
In addition, an avalanche warning was posted through Wednesday afternoon for the western slopes of the Cascades as the snow level rose above the passes. Highway 2 was closed at Stevens Pass for several hours due to an avalanche across the roadway before reopening around 3:30 p.m.
Photos of Avalanche on Stevens Pass pic.twitter.com/zJ7IcjaGCgTrooper Mark Francis (@wspd7pio) March 5, 2014Traffic was backed up on several area highways Wednesday morning due to water over the pavement and traffic accidents. One persistent trouble spot was Highway 520 at 108th Avenue NE, where rainwater backed up over part of the roadway.
Travel times between cities were as long as 103 minutes between Everett and Bellevue and 94 minutes from Everett to Seattle during the commute's peak just after 8 a.m.
There were also reports that a mudslide near Algona has knocked an abandoned house off its foundation, but was causing no other problems.
Round 2 Tonight
An even stronger storm was marching toward Western Washington for Wednesday evening, expected to bring a renewed heavy rain through the night and well into Thursday. Additional rainfall totals of 1-2 inches are possible in the lowlands, with another 2-6 inches possible in the mountains.
In addition, gusty winds will be along with this storm, although as of this point it doesn't look like winds will be severe. Best chance of gusts nearing 40-45 mph will be from south of Seattle and along the central and southern coast with most other ares in the 25-35 mph range.
Expect potential urban and small stream flooding with this second storm, as well as an increased risk of land and mudslides.
Breaks in rain give rivers a break
While it has been very soggy this week -- Seattle is just a bit over a half-inch short of its average 3.72" March monthly rain total already -- we've been a bit lucky in that the rain hasn't been too consistent. Our worst river flooding events come when we have a warm, Pineapple Express-type system park over the region for 36-48 hours bringing a relentless rain to the mountains. This time our heavy rains are coming in four spurts -- the storm Sunday into Monday, the Tuesday morning storm, the storm early this morning, and the one coming Wednesday night.
But the breaks between those storms -- even though they were/are brief -- are enough to at least get some of the heavy rains down the river drainages and keep the issue from compounding. (Plus we were a bit lucky in that those first two storms had low snow levels to keep some moisture stuck on the mountains as snow.) It's akin to having someone filling up a large bucket of water, toss it on you, then go refill it while the water drips off you before dousing you again, as opposed to just blasting you non-stop with a fire hose.
So as of right now if rainfall totals hold to forecasted values, we could see some minor flooding but major flooding is not expected. You can track current river status at NOAA's Advanced Hydrologic Prediction Service.
A Brief Wring-Out
Forecast models suggest we'll dry out Thursday night and remain dry Friday. A new storm will push through during Saturday afternoon into Sunday but it looks like a fairly routine event. After the weekend, a much more calmer weather pattern is in the offing.