WA state flooding/weather? Did I miss a thread? How's everyone?

[masraum]

Did I miss a thread? I've been seeing stuff about flooding and weather in Washington state. I didn't see as much as I would have thought considering, and didn't see anything here. I know we've got folks in Washington.

How is everyone? Anyone impacted?

https://www.pbs.org/newshour/nation/historic-floods-have-washed-away-homes-and-stranded-families-in-washington-state

[LWJ]

It is supposed to be a big deal. I am in Oregon and we seem to have missed the bad stuff. Everyone I know in WA is talking about it. A buddy almost lost his private bridge to his house in Oregon last week. Creek didn't quite get high enough. Close one.

[Jeff Higgins]

It has been about the worst flooding that I can remember, and I have lived in and around the Seattle are for my entire 65 years.

We have a rather unique geography/weather combination that contributes to this during the Fall and Spring. We have two large mountain ranges, the Olympics to the west of the Puget Sound area, and the Cascades to the east, which divide Western Washington from Eastern Washington. Our weather comes over the Olympics and stalls up against the Cascades, which impede its eastern progress. As a result, there are two distinctly different "Washingtons" - Western Washington and Eastern Washington. The west side gets all of the rain, the east side is essentially high desert.

It never gets all that cold here, our weather tempered by the Pacific Ocean. As a result, the snow levels in our two mountain ranges fluctuates dramatically, especially during Fall and Spring. The snow level can drop to sea level and be right back up to 10,000 feet in a week at this time of the year. The rain, or if cold enough, the snow essentially does not stop in the Fall and Spring. So we get huge snow packs that melt rather suddenly, accompanied by that steady rain. Talk about a recipe for disaster, with water levels in our river valleys rising at alarming rates when we hit this combination. We have one really big river system, the Columbia and Snake, that drain Eastern Washington (and B.C., and Idaho), but a myriad of smaller systems on the west side of the Cascades that all drain right through the east side of the Puget Sound area, including Seattle, Tacoma, Olympia, and many other smaller cities. And, well, they soon get overwhelmed by melting snow and continued rain.

Once "winter" really sets in and snow levels in the Cascades stabilize, this all stops. Only to start again during the spring melt and continuing rain. None of this would be all that much of a problem, of course, if only common sense were applied with regards to development. It doesn't. So we see massive development in our flood plains. That development has now transformed "100 year" flood plains into five to ten year flood plains, with all of the pavement limiting drainage.

It's a real mess, with no real solution. Mother Nature always wins...

[jyl]

Apparently the roads to the ski resorts are washed out? Adding insult to injury.

[masraum]

Thanks for all of the information, Jeff. It sounds like this is one of those things that's expected, but then comes around and is on the extreme end and surprises everyone like the big hurricane and/or flooding events around the Gulf of Mexico and East Coast.

Houston has a similar issue, where we are expected to flood, but developers have come in and according to the articles that I've seen built tens of thousands of residences in the flood plains. So then you've got homes and roads covering the flood plains, and because of all of the paved over ground, there's no place for the water to go other than up.

Yesterday, I saw a video of a home floating down a river. I've seen photos of washed out roads. I have been surprised by how little media I've seen on it, almost like a non-issue.

[Jeff Higgins]

Yes, access to the ski resorts has been all but cut off. We also have a number of resort towns, the most notable being Leavenworth, a German themed town, that are dependent upon tourism year round. They are all but cut off as well.

We have five mountain passes over the Cascade range, only two of which remain open through the winter. They are high enough that they do not flood, of course, but they have had some severe mud slides caused by the rapidly melting snow and steady rain, causing them to close as well, temporarily.

It never rains very hard here at all. Just all the time. We don't get the torrential downpours , much less the hurricanes found in other parts of the country. So, to trigger the kind of flooding and mud slides we are experiencing right now, we need to store it up. The early snow pack serves to do just that. The worst thing it can do around here is snow early in our mountains, 'cause we know it's gonna melt, at least a few times, before it gets cold enough to stabilize. Some years are worse than others.

[jhynesrockmtn]

Originally Posted by jyl

Apparently the roads to the ski resorts are washed out? Adding insult to injury.

They don't have enough snow to be open yet, which is quite unusual. Highway 2 is washed out which is Stevens pass. So yes, when they do get some snow, they won't open until the roads are repaired. I live in eastern WA and our ski resort openings have either been pushed back, or opened and then closed again. We had a high of 57 in Spokane the other day. Record high's for this time of year. I drove over to Seattle the 1st weekend in December and the main pass had almost no snow on the ground.

We're supposed to get a big windstorm overnight tonight. We'll see if that actually happens. If as predicted, it should come with a lot of downed trees and loss of power. We are stocking up today.

[Skip Newsom]

Great background explanation Jeff!

This is not over by any means either, 55mph winds forecast for tomorrow and continuing rain. The Skagit is supposed to crest again over flood stage. The soil saturation allows trees to go down more easily, so it’s an additional impact to the crazy amount of flooding.

Last night the Town of Pacific had a levee failure and folks woke to evacuation orders from officers knocking on doors and a helicopter at 2 AM.

A few big reservoirs always start draining down in fall to allow for spring run off, they were used to absorb and slow impacts up north.
The towns down stream on the Skagit would have been completely devastated.

Ross lake was down to 1584’ lake level, it went up 10’ in 48 hours- it’s a 23 mile long lake/reservoir, a mile or more wide in places and over 500’ deep near the dam.
Baker lake went up 11’ in the same period, it’s 8 miles long.
I’d bet both spillways on Ross are dumping- I would love to see and hear that! same with Diablo and Gorge lakes all situated in that valley and hydro power projects.

Prior to that the Skagit had severe flooding and is still a risk if a levee fails, the Skagit drains 150 miles of mountain sides, and is second biggest in the state.


We have been lucky where I’m at about 45 minutes North of Seattle, seems the biggest rainfall totals were north and south of us.
The Stilliguamish River is 3 miles north, it hit flood stage and caused some closed roads but nothing major comparatively.

I’m hearing Highway 2 will take months to repair, that a major E-W route. No doubt lots of my favorite trails are also damaged, the full impacts won’t be known until spring.

The Governor is filing a Major Disaster Declaration asking for more support from the feds.
National Guard are out doing a ton of work and support, I saw a convoy heading South on I 5 recently.
I appreciate them putting themselves in harm’s way and in poor conditions!

[jyl]

What a mess. Sorry you WA'ers are going through this.

[masraum]

highway 2 closed for months...

[masraum]

[masraum]

[pwd72s]

Originally Posted by LWJ

It is supposed to be a big deal. I am in Oregon and we seem to have missed the bad stuff. Everyone I know in WA is talking about it. A buddy almost lost his private bridge to his house in Oregon last week. Creek didn't quite get high enough. Close one.

Hang in, supposed to get VERY WET in the entire Willamette Valley tomorrow...

[LWJ]

We may not be out of the woods yet. And Washington may be about to get a lot worse. Lots of rain coming down now and the forecast is for pretty significant accumulation this weekend. The soil could not be more saturated. There will be slides at a minimum.

[pwd72s]

So far so good here 100 miles South of PDX..light winds and the usual light rain. The Irony for me personally is that there is an 18KW Generac unit sitting on a slb here, but not hooked up here because all the power company linemen are busy elsewhere...I've been given a maybe date of Jan 5 before the unit becomes functional.

[Jeff Higgins]

Yes, soil saturation is another inherent problem in this area. Anyone remember our huge Osso mud slide of a decade ago? Took out most of the town of Osso and killed dozens. Tragically, the USGS had flagged that very hill way back in the 1950's, if not earlier, as enough at risk as to ban development below it. Alas, someone sued and won that right. We see how that worked out. But I digress.

Much of our forested land is in a similar state of saturation. Think big blobs of pudding with trees growing out of them. Too much additional water too quickly and it breaks over the point where that particular mass at that particular slope just can't hold any longer and down it comes.

We do, periodically, get earthquakes as well. Shake that mound of pudding and it takes much less saturation to make it come down. That's what happened in Osso. Thank God we have not had an earthquake in the middle of all of this.

[LWJ]

^^^I have never been able to look into the future but we used to have family in Darrington. Driving past Osso, I was shocked and commented at all the prior slides and the houses directly below to my family. It was crystal clear to me what would happen.

A few years later, I was unfortunately 100% correct.

Mother Nature bats last.

[jyl]

Mt Hood Meadows had 4” snow this am, then temps rose to 38F :-(

Next seven ish days it is supposed to be below freezing up up there, but not greatly below, and this seem to be leaning warm vs forecasts.