Wednesday, January 7, 2009

Flood Day

It was kind of surreal for me this morning....I biked to work absolutely dry and in warm conditions, while ten miles to the south there was moderate rain and all hell was breaking loose in the mountains. One of the most profound rain shadows I have experienced in a while (see the radar). On the radar this morning you also see how the focus of the heaviest rain has moved east and south of Seattle since last night. And NO rain in an east-west band from Seattle to Lynnwood stretching west towards the Olympics. You don't have to go too far east to pick up heavy rain--North Bend is being pummelled. The computer models have consistently showed the development of this rain shadow and is a prime example of how for the weather prediction enterprise has come in the last ten years. Forecasting rain shadows is FAR easier than predicting snow!

An interesting graphic based on the radar I have never shown you is the storm-total analysis. Basically, one can relate the radar signal scattering off the rain to precipitation rate, and then add that up over time. So weather radar can be used as a rain gauge...although an imperfect one.

I have attached the storm total rain for the past three days. Remember, there is major blockage of the beams by the Olympics and Cascades...so you are not seeing the whole picture. But what you can see is fairly daunting. The is a broad region of greater than 6 inches (yellows) surrounding the rain shadow and substantial areas of ten inches or more (reds) on the windward slopes of the Cascades. We cannot see the heavy rains on the SW side of the Olympics because there is no radar coverage there (another reason why our congressional delegation needs to secure the resources to acquire a coastal radar! With all the infrastructure spending being discussed this essential piece of warming and prediction infrastructure should be a high priority. If we can spend 7 million for solar panels on top of Qwest field, surely we can afford the radar which would greatly improve weather prediction and warnings!).


Both Stevens and Snoqualmie passes have gotten more than 7 inches so far. North Bend has received around 5 inches. And we are only half-way through this event.

The hydrological models are going for a very major event on many of our local rivers, with extensive flooding to be expected. As I noted in my last message, the NWS has an excellent web site with detailed river flow information. I should mention that Chapter 3 of my book describes the nature of NW floods and reviews major floods of the past.

Want good news?...the weather models are going for a dry day on Friday, some light showers over the weekend, and an extended dry period next week. You will think you are in California.

30 comments:

Brad said...

No rain and 50°F in Poulsbo at 5 am when I went for a run. That's warmer than many mornings in July/August.

TrickyCoolJ said...

Sounds like snowboarding anytime soon is out of the question. Just curious, is it ever possible for that really cold arctic air (like from two weeks ago) to collide with a pineapple express? Or is the pineapple express too strong to allow that to happen?

...sure wish I would have taken that intro to weather class when I was still at UW.

Joseph Ratliff said...

Raining like mad here in Lacey...roads are flooded by the sidewalks...except in front of where I live, because we as neighbors have cleaned our drains... go figure ;)

Stay safe and dry out as soon as possible everyone. Pay attention to school early dismissals and stuff if you have children. KOMO4 is on right now mentioning that on news coverage 11:30am.

Josh said...

Plenty of moisture up here in Bellingham. Numerous urban and small stream flooding and the bigger rivers rising…..Shot video of Squalicum PKW. Complete river running down the PKW….Bellingham just on the edge of the rain shadow transition zone. I think with a more southwest or southern flow Bellingham proper could have received even more…. High Pressure on the way? Fallowed by artic incursion late next week???

Anonymous said...

We're just east of North Bend. Both the access roads into our neighborhood are blocked by a huge landslide. The high road, Dorothy Lake has slid onto our road, SE Middle Fork. WSDOT is going door to door to let us know we are trapped indefinitely. Have to walk out 2.5 miles to nearest safe road. We've also lost power because of the slide. Yeah for generators! We're on the Middle Fork Snoqualmie - 55 feet above it, thank goodness--and the river is wild. We went through the 2006 storm without a hitch, but I think the 2 feet of snow with the rain on top of it is going to make this a much more damaging storm even if the flooding isn't as bad. Good luck everyone and stay safe.

Jim G said...

Bellingham was simply moderate rain off and on yesterday until I slept at midnight. This morning I woke to schools closed, power outages and road flooding in totally unexpected intersections.

Sure enough, overflow stream water was running in many unexpected major streets. Stormwater Retention Ponds that have never seen water were full to overflow. A jet-ski was reported in one low-lying urban intersection. Many roads are closed.

Years ago, I analyzed 10-years of 15-min local rain-data, looking for local "design storms." The worst 24-hour rains would never be described as "storm" -- they were "continuous boring drizzle" sometimes compounded by saturated surface or snow-melt.

Fact is I never found any search definition for my "design-storm" other than total 3, 6, 12 and 24-hr accumulated rainfall.

Thanks for your many blog insights.

Ashley said...

No rain and 53˚F here in Woodinville. Wind is still heady. Little Bear Creek has run over in the Basset Pond area (they have 165th closed through there because of it).

And have I mentioned how much I love this blog lately? Because I do, I really really do.

Michael said...

Holy cow! The Queets is up to 87,800 cfs. The 53-year record had been 61,400 in 2002. I can't imagine how big it will be tomorrow!

USGS REal-Time Water Data: Queets

Anonymous said...

Just took visitors on the long route to grocery store via looking at the Newaukum and Chehalis rivers. We are likely to be stranded on our hilltop for a couple/few days. I fear a number of our businesses will not survive a 2nd record flood in 13 months. Newaucum is still flowing freely into the Chehals, which has about 5 feet or so before it starts going over the road. Collateral damage will hit us for about $1000, a pittance compared to what so many face. Rob

Anonymous said...

Josh, no arctic intrusion late next week. Long range models do not show anything like that. BUT as long as there is an amplified ridge, it is a possibility in the long range. Many long range forecasters think it could happen, especially Ed Berry, who said 4 weeks before we got our cold that the Pacific Northwest would get arctic air. He now thinks a similar pattern is likely (not saying it would be two weeks long with record snow, maybe more of a normal arctic outbreak).

RedmondMan said...

sigh

Another gloomy, gloomy day in the shadow. Weather all around me, but gray clouds and wind where I am at. I find this weather super depressing. I hope something shifts soon.

Anonymous said...

We had huge fallen tree limbs in our back yard this morning...glad nobody was outside when they fell.

Good idea, cleaning out the storm drains. I really think the reason the snow melt was SOOOOOOOO uneventful was because people were told to clean storm drains.

With all of the fallen debris, people need to continue keeping their storm drains clean. I know this won't stop all flooding, but it will certainly prevent some.

Anonymous said...

We had major rain east of renton, and over through may valley last night. Today, there is still a bit of rain there and in Issaquah as well. On SR900 this morning, the drainages were raging like a small river, and we had flooding on the roads in a few spots. One guy was outside cleaning the drainpipe that runs under his driveway.

Anonymous said...

I talked to someone in Centralia today who owns a business down there. He was flooded 13 months ago and from the looks of it, they will have the same situation again. The good news is they acted quicker and had U-Hauls lined up in front to move stuff out.

Anonymous said...

Here's another view of the storm totals from radar as displayed in Google Earth (looking east from the Olympics towards the Cascades and generated from the NWS page at http://radar.weather.gov/ridge/kmzgenerator.php). The train shadowing and total amounts are pretty impressive...

christopher said...

Uncanny rain shadow here in between Poulsbo and Silverdale on the Kitsap Pen. as well as 50 degrees. All of the 12 inches of snow is gone. Only the bottom of Frosty is left. I am very thankful that we are perched on a ridge with no major rivers around.

Joan Neslund said...

Raining hard at Holden Village, 48.2N 120.75W (Elev. 3224 ft), avalanches have closed the road and much of the 130" of snow that we have had is now turning to slush. We can see a few avanches from the village and we know that we have a huge possiblity for more.

Our biggest danger is the snow slidding off of the buildings (roofalanches we call them). We have to route our paths to avoid the tons of ice and snow that slides off in this warm weather. Warm weather here about 38 degrees and pretty ugly for this time of year.


http://ajneslund.blogspot.com

Brian said...

Hey Cliff. Can we expect this rain shadow to collapse tonight? Some forecasters are calling for it, others aren't. What do you think?

Fes said...

Hey Cliff, when can we expect a return back to cooler temps with drops in the freezing level for the mountains along with snow?

Anonymous said...

Seems like the rain shadow has pretty much collapsed. We had very little rain on Bainbridge up until about 30" ago. Now it's raining hard but not as windy.

srexecmark said...

You don't have to go very far to see the mess this is creating:
http://www.komonews.com/news/37226989.html

Big slide at Snoqualmie Pass.

artsandletters said...

You can follow in real time the data for the rising rivers here:

http://waterdata.usgs.gov/wa/nwis/current/?type=flow

Anonymous said...

so who is going to pay for the time i miss at work after they close 1-5?

Walter in West Seattle said...

0.0% - Probabilistic prediction of thinking I'm in California next week.

Anonymous said...

I'm all for coastal radar, but why the gratuitous trade-off against some solar collectors that begin to give City Light some experience with this form of distributed generation before the solar revolution hits Seattle. Which will be sooner than many think. If we want to point a finger at something, how about a $307,000,000,000 guarantee of the obligations of Citygroup, with zero due diligence and no Congressional involvement in the decision? That's approximately 200,000 times more than the solar panels cost.

Anonymous said...

"Walter in West Seattle said...
0.0% - Probabilistic prediction of thinking I'm in California next week."

100% correct!

Anonymous said...

Lakewood, Steilacoom, back side of N Ft. Lewis

Chris...How much does a radar site cost? What are the major reasons UW/private money can't put up what we need?

I know, dumb question, and I'm not even a blonde, but I'd like to know.

Anonymous said...

How is thinking you are in California good news??? Aren't you a meteorologist? How can you LIKE boring extended periods with no weather at all??

Anonymous said...

All I can say is it is now 9:30 pm here in Kingston, and the real rain is just starting to hit us here. There were showers off and on this afternoon, but to turn on the TV and see the rain amoints that were being received throughout Western Washington? Wow.

All I can say is I hope those in flood areas can get away and stay safe.

Peter said...

Unless I missed it (we were evacuated from Puyallup so I have not read all your blogs) you haven't mentioned that this was a classic "rain on snow" event. The 70 inches of snow you mentioned during the first days of the year stored a lot of water. Then the system switched to a Pineapple Express and the warmth and the rain melted a good deal of snow (depending on the elevation.) So a significant amount of the water in our rivers came from melting snow from previous storms, not just from the 12+ inches in this storm. Since this is a well-described phenomenon I would think your readers would be interested in it.

Peter