Washington Landslide Death Toll Grows to 14

By: Dr. Jeff Masters , 2:03 PM GMT on March 25, 2014

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The death toll has grown to fourteen from Saturday's massive landslide near Oso, Washington, located about 50 miles north-northeast of Seattle. At least seven were injured, and 176 are listed as missing, though this total is likely to decrease dramatically as missing people check in. The landslide was triggered by unusually heavy rains over the past 30 days in the region. A personal weather station located about ten miles west of the slide recorded 13.81" of precipitation in the 30 days prior to the slide, including 5.17" in the ten days just before. Precipitation imagery from NOAA's Advanced Hydrological Precipitation Service (Figure 2) shows that the 30-day precipitation amounts in the region were more than 8" above average--about double the usual amount of rain for this time of year.


Figure 1. The Oso, Washington area before the March 22, 2014 landslide as seen on Google Earth (top) and after the landslide, as photographed by the Washington Department of Transportation (bottom.) The landslide blocked the North Fork of the Stillaguamish River and Highway 530.


Figure 2. Precipitation for the 30-day period ending March 24, 2014, was 150% - 200% of average in Oso, Washington--about 8" above average. Image credit: NOAA/AHPS.


Figure 3. Predicted precipitation for the 7-day period ending on Tuesday, April 1, 2014. The landslide area to the northwest of Seattle is expected to receive 2 - 4" of precipitation, which will slow recovery efforts from the landslide. However, the rains over Northern California will be welcome, helping to fill drought-depleted reservoirs as that state's dry season approaches. Image credit: NOAA/HPC.

A re-activation of an old landslide
According to Dave Petley, Professor of Hazard and Risk in the Department of Geography at Durham University in the United Kingdom, it is clear that major landslides have occurred here on many previous occasions, so much so that the landslide is known as either the Hazel landslide or the Steelhead landslide. In his excellent Landslide Blog, my go-to source of information for any landslide, he writes: "The landslide has been widely reported as a mudslide. In terms of the lower portion, which did the damage, this is correct, although in places it might have been more of a mudflow than a mudslide. However, the upper portion is a rotational landslide–the rotated block with the fallen trees is very clear. A working hypothesis would be that this block failed catastrophically, transferring load onto the block below, which in turn generated very high pore water pressures, causing fluidisation and a very rapid mudflow that struck the settlements across the river." He writes that the last event on a similar scale he knows of was the 25th December 2003 debris flow in San Bernadino County, California, which killed sixteen people. Weather historian Christopher C. Burt has a post about the worst landslides in U.S. history, which puts this week's landslide in context.

The Yakima Herald has a very nice article that details the chronology of events on the Oso landslide. This includes:
• 1949: A large landslide (1000 feet long and 2600 feet wide) affected the river bank
• 1951: Another large failure of the slope; the river was partially blocked
• 1967: Seattle Times published an article that referred to this site as “Slide Hill”
• 1997 report, by Daniel Miller, for the Washington Department of Ecology and the Tualialip Tribes
• 1999: US Army Corps of Engineers report by Daniel and Lynne Rodgers Miller that warned of “the potential for a large catastrophic failure”
• 25 January 2006: large movement of the Steelhead landslide blocked the river



When Will Spring Come For REAL? Join Me at 5:30pm EDT Tuesday for a Google Hangout Discussion
Spring has officially begun for those of us in the Northern Hemisphere, but it's still more like winter in the Midwest and Northeast U.S. In celebration of the new season, I'll host a 15-minute Google Hangout on Tuesday, March 25th at 5:30pm EDT to review where on Earth the most severe winter weather is occurring, and forecast when those of us still experiencing winter can expect to see Spring--for real! I'll focus on the forecast for four cities: Detroit, Boston, Seattle, and Moscow, and discuss some of the remarkable weather events those cities have seen this month. You can watch the hangout by visiting our Weather Underground Spring Forecast page.



Jeff Masters

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fri nite into saturday......................
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963 MB's at 9am Atlantic.

God knows what the pressure is now....most likely much lower.
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Quoting 730. Bluestorm5:
From Twitter. NWS Boston think Bob and '93 storm had stronger winds in Nantucket.

@NWSBoston 6m
Evaluating Nantucket ASOS data, today's 82 mph gust seems to be the fastest gust recorded since ASOS data flow began Apr 1, 1998

‏@NWSBoston 6m
Data records are scarce for Nantucket, but likely faster wind gusts were observed during Hurricane Bob (1991) & perhaps the Superstorm of 93


If that storm was 100 miles further west....those records likely would've been smashed.
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GFS for Saturday..again gee..................
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whew gonna drop a foot of snow...............
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From Twitter. NWS Boston think Bob and '93 storm had stronger winds in Nantucket.

@NWSBoston 6m
Evaluating Nantucket ASOS data, today's 82 mph gust seems to be the fastest gust recorded since ASOS data flow began Apr 1, 1998

‏@NWSBoston 6m
Data records are scarce for Nantucket, but likely faster wind gusts were observed during Hurricane Bob (1991) & perhaps the Superstorm of 93
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Convection building around the center? what the...

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Quoting 724. PedleyCA:
Landslide Blog

Here is more info on that slide...
gee so many missing people over there..
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Landslide and Barrier Lake Near Oso, Washington
On March 22, 2014, a rainfall-triggered landslide near Oso, Washington sent muddy debris spilling across the North Fork of the Stillaguamish River. The slide left an earthen dam that blocked the river, causing a barrier lake to form. The Operational Land Imager (OLI) on the Landsat 8 satellite acquired this image of landslide debris and the barrier lake on March 23, 2014.


Image Credit: NASA Earth Observatory image by Jesse Allen, using Landsat data from the U.S. Geological Survey

Caption: Adam Voiland

Large Image



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Quoting 723. HurricaneCamille:


the 1993 storm was definitely larger....however the satellite presentation of this one certainly looks more impressive to me.
Actually, I looked at the pictures again and they both similar in size. I'm just thankful we got to observe a storm like 1993 storm this winter (maybe not so thankful for you or your fellow Canadians...)
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Landslide Blog

Here is more info on that slide...
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Quoting 719. Bluestorm5:
Right now, the storm is analysed at 962 mb. Storm of the Century in March of 1993 was 960 mb so there's good chance that this storm will end up being stronger than Storm of the Century. However, looking at the satellite pictures and reports, I'll say 1993 storm is still more impressive due to the track and the size. Again, only if the low deepened sooner and the track is farther west...

1993 storm:



2014 storm:





the 1993 storm was definitely larger....however the satellite presentation of this one certainly looks more impressive to me.
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Quoting 717. yonzabam:


You don't have to have planes in the air to measure wind speeds. It's a (very) reasonable question - are nor'easters subject to the same wind speed duration criteria as hurricanes?


When the storm is off the coast the odds of a buoy picking up the true peak winds are the best shot we have. Even then, I doubt the true peak winds will be found.
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721. beell
Quoting 720. ricderr:

Only little odd thing that sticks out to this arm-chair guesser, ric. Not sure if you could call it a disconformity.



i see what you're showing....not sure what it is....nor do i have any clue how long ago it took place...but since i am an armchair expert :-) i'm going to positively state that's due to a volcanic episode


Could be-it's the right color!
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Only little odd thing that sticks out to this arm-chair guesser, ric. Not sure if you could call it a disconformity.



i see what you're showing....not sure what it is....nor do i have any clue how long ago it took place...but since i am an armchair expert :-) i'm going to positively state that's due to a volcanic episode
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Right now, the storm is analysed at 962 mb. Storm of the Century in March of 1993 was 960 mb so there's good chance that this storm will end up being stronger than Storm of the Century. However, looking at the satellite pictures and reports, I'll say 1993 storm is still more impressive due to the track and the size. Again, only if the low deepened sooner and the track is farther west...

1993 storm:



2014 storm:



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Levi Cowan ‏@TropicalTidbits · 58 seg
And warm seclusion begins. RAP 16z analyzed 850mb air temperature: Link

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Quoting 713. HurricaneCamille:


Be reasonable here, we don't have recon out investigating the system. In reality we don't know for sure just how powerful she is.


You don't have to have planes in the air to measure wind speeds. It's a (very) reasonable question - are nor'easters subject to the same wind speed duration criteria as hurricanes?
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Damm. Canadian 12Z April 5th. Below zero across the midwest. BRRRR!

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Quoting 703. hydrus:

One can see the two centers here.


Classic F-word?
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Quoting 703. hydrus:

One can see the two centers here.


Looks like one center and a dry air slot to me...
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Quoting 707. yonzabam:


Hurricane winds have to be sustained for 60 seconds to be 'official'. Is it the same for nor'easters? Official UK storm speeds are 10 seconds sustained, so an 80 mph gale here isn't comparable to a cat 1 hurricane.


Be reasonable here, we don't have recon out investigating the system. In reality we don't know for sure just how powerful she is.
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Just went outside and got some footage. Not really that windy out yet (i'd guess its gusting around 70 KM maybe a little less) Getting whipped in the face with ice pellets galore. Definitely coming down real heavy.
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711. beell
Quoting 685. ricderr:
i don't see any evidence of clear cutting nor has any hydrologist stated that was the case....in fact they say a major cause of this was the undercutting of the banks of the river below






Only little odd thing that sticks out to this arm-chair guesser, ric. Not sure if you could call it a disconformity.
(click for larger image)

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Quoting 708. Mikeylikesthesite:
The backside of the nor easter when that passes what est' wind gusts do u guys think that may be, just curious im quite certain our power will be done for a large area of Nova Scotia?


I suspect your winds will gusts to 80 soon just as I said in the e-mail a few days back.

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Oh, if only that storm took more western track and exploded earlier...
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The backside of the nor easter when that passes what est' wind gusts do u guys think that may be, just curious im quite certain our power will be done for a large area of Nova Scotia?
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Quoting 701. LargoFl:
regardless of what month this is..this storm IS a hurricane..........URGENT - MARINE WEATHER MESSAGE
NATIONAL WEATHER SERVICE CARIBOU ME
1235 PM EDT WED MAR 26 2014

ANZ050-270045-
/O.CON.KCAR.HF.W.0001.000000T0000Z-140327T0600Z/
COASTAL WATERS FROM EASTPORT ME TO SCHOODIC POINT ME OUT 25 NM-
1235 PM EDT WED MAR 26 2014

...HURRICANE FORCE WIND WARNING REMAINS IN EFFECT UNTIL 2 AM EDT
THURSDAY...

* WINDS AND SEAS...NORTH WINDS 40 TO 55 KT WITH GUSTS UP TO 75 KT.
SEAS 13 TO 18 FEET.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HURRICANE FORCE WIND WARNING MEANS WINDS OF 64 KNOTS OR GREATER
ARE IMMINENT OR OCCURRING. ALL VESSELS SHOULD REMAIN IN PORT...OR
TAKE SHELTER AS SOON AS POSSIBLE...UNTIL WINDS AND WAVES SUBSIDE.

&&

$$


Hurricane winds have to be sustained for 60 seconds to be 'official'. Is it the same for nor'easters? Official UK storm speeds are 10 seconds sustained, so an 80 mph gale here isn't comparable to a cat 1 hurricane.
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Quoting 703. hydrus:

One can see the two centers here.


Models showing our first real threat of severe weather next week.


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One can see the two centers here.
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Quoting 652. KEEPEROFTHEGATE:
everything will be fine as long as there is no shots of the shower curtain

just kidding

Did I see something about "The Shower Curtain"

hahahahaha What memories :o)
Hows everybody today??? Here on the Gulf Coast it's still a bit "Cold"

Taco :o)
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regardless of what month this is..this storm IS a hurricane..........URGENT - MARINE WEATHER MESSAGE
NATIONAL WEATHER SERVICE CARIBOU ME
1235 PM EDT WED MAR 26 2014

ANZ050-270045-
/O.CON.KCAR.HF.W.0001.000000T0000Z-140327T0600Z/
COASTAL WATERS FROM EASTPORT ME TO SCHOODIC POINT ME OUT 25 NM-
1235 PM EDT WED MAR 26 2014

...HURRICANE FORCE WIND WARNING REMAINS IN EFFECT UNTIL 2 AM EDT
THURSDAY...

* WINDS AND SEAS...NORTH WINDS 40 TO 55 KT WITH GUSTS UP TO 75 KT.
SEAS 13 TO 18 FEET.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HURRICANE FORCE WIND WARNING MEANS WINDS OF 64 KNOTS OR GREATER
ARE IMMINENT OR OCCURRING. ALL VESSELS SHOULD REMAIN IN PORT...OR
TAKE SHELTER AS SOON AS POSSIBLE...UNTIL WINDS AND WAVES SUBSIDE.

&&

$$
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Quoting 699. HurricaneCamille:
Here in Sydney the wind is really picking up.....snow has picked up as well. It's looking pretty damn white out there lol

Hope you stay safe, dry and warm over there!
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Here in Sydney the wind is really picking up.....snow has picked up as well. It's looking pretty damn white out there lol
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Quoting 648. Dragod66:


out my bathroom window!
"She came in through the bathroom window, protected by a silver spoon....
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UKMET..when they warn of a coming Nor'easter THIS is what they mean..geez....
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Eric Fisher ‏@ericfisher · 2 h
Spiking MT @stormchaser4850: Developing: (@NSTAR_News) (@nationalgridus) reporting a combined 13,500+ customers without power in MA

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Levi Cowan ‏@TropicalTidbits · 5 min
Red dot is buoy 44150 - measured 973mb at 15z. RAP analysis was 6mb too high with 979mb at that location: Link
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Chris Beal ‏@NJSnowFan · 9 min
Wow MT "@WesternMEwx: Coastal #Maine Jonesport buoy gust of 101 MPH!! (87.4 kts) http://1.usa.gov/1gCgA3o Link




guess this makes the 50 mph gusts we're expecting this evening pale in comparison.....i won't complain now
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Nam for tomorrow morning..stay safe folks........
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The Weather Channel ‏@weatherchannel · 3 min
At 11:35am EDT a buoy 23 mi SE of Jonesport, Maine recorded a peak gust of 112 mph. #Noreaster #Blizzard

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Quoting 688. Luisport:
Chris Beal ‏@NJSnowFan · 9 min
Wow MT "@WesternMEwx: Coastal #Maine Jonesport buoy gust of 101 MPH!! (87.4 kts) http://1.usa.gov/1gCgA3o Link
yes this is a real big and dangerous storm,hope everyone is heeding their local warnings
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ground saturation played a role as well


yep...sure did
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689. Skyepony (Mod)
Station 44005 (LLNR 820) - GULF OF MAINE - 78 NM East of Portsmouth, NH

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Chris Beal ‏@NJSnowFan · 9 min
Wow MT "@WesternMEwx: Coastal #Maine Jonesport buoy gust of 101 MPH!! (87.4 kts) http://1.usa.gov/1gCgA3o Link
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Seems like a ridge is fighting for its very life over northern Europe. What a display of meteorological bravery and a weird cloud formation lined up N-S heading to Iceland.

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Quoting 685. ricderr:
i don't see any evidence of clear cutting nor has any hydrologist stated that was the case....in fact they say a major cause of this was the undercutting of the banks of the river below









ground saturation played a role as well
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i don't see any evidence of clear cutting nor has any hydrologist stated that was the case....in fact they say a major cause of this was the undercutting of the banks of the river below









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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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