The ARkStorm: California's coming great deluge

By: Dr. Jeff Masters , 4:04 PM GMT on January 28, 2011

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For thirty days and thirty nights the rain fell in unending torrents. By the end of the biblical deluge, rivers of water ten feet deep flowed through the streets of Sacramento, and an astounding 29.28 inches of rain had fallen on San Francisco. According to wunderground's weather historian, Christopher C. Burt, in the Sierras, the moist flow of air from Hawaii--often called an "atmospheric river" or the "Pineapple Express"--hit the steeply sloping mountainsides and rose upwards. The air expanded and cooled, causing truly prodigious rains, with the mining town of Sonora receiving 8.5 feet of rain over a 2-month period. The resulting floods inundated California's Central Valley with a lake 300 miles long and 20 miles wide.

The above event occurred in January 1862, and similar extreme rain events have deluged in California seven times in the past 2,000 years--about once every 300 years. Great storms like the flood of 1862 will happen again. If the planet continues to warm, as expected, the odds of such an event will at least double by 2100, due to the extra moisture increased evaporation from the oceans will add to the air. A group of scientists, emergency managers, and policy makers gathered in Sacramento, California earlier this month to discuss how the state might respond to a repeat of the 1862 rain event--the ARkStorm Scenario. The "AR" stands for "Atmospheric River", the "k" for 1,000 (like a 1-in-1000 year event), and of course "ARkStorm" is meant to summon visions of biblical-scale deluge, similar to the great flood of 1862. The team's final report envisions the most expensive disaster in world history, with direct damages and loss of economic activity amounting to $725 billion.

"Atmospheric Rivers" was a term coined in the 1990s to describe plumes of moisture that ride up out of the subtropics into the mid-latitudes along the axis of a cold front. Traditional water vapor satellite imagery does not show these plumes very well, and it was only when microwave satellite imagery from polar orbiting satellites became available in the late 1990s that the full importance of these Atmospheric Rivers came to be revealed. Atmospheric Rivers account for a significant portion of California's cold season rainfall and snowfall, and an entire session was devoted to them at the December 2010 American Geophysical Union (AGU) meeting in San Francisco, the world's largest Earth Science meeting.


Figure 1. The total amount of rainfall one could get if all the moisture in the air were condensed and fell out as rain is called the Total Precipitable Water (TPW). Here, TPW values from microwave satellite measurements are plotted, and show a plume of very moist air connecting the subtropics near Hawaii with Southern California. TPW vales in excess of 20 mm (about 0.8 inches, blue and warmer colors) are "Atmospheric Rivers", and are often associated with heavy rainfall events capable of causing flooding. This Atmospheric River occurred on December 21, 2010, and brought very heavy flooding rains to Southern California. Image credit: University of Wisconsin CIMSS.

California's Delta Region levees at high risk of failure
Much of Central California's water supply and agricultural areas are protected by an antiquated and poorly maintained set of levees along the Sacramento and San Joaquin Rivers that are in serious danger of failure during an extreme flood or major earthquake. The 1,600 miles of levees protect 500,000 people, 2 million acres of farmland, and structures worth $47 billion. Of particular concern is the delta at the confluence of California's Sacramento and San Joaquin rivers, about 80 miles inland from San Francisco Bay. The Delta Region receives runoff from more than 40% of California, and is the hub of California's water supply system, supplying water to 25 million people and 3 million acres of farmland. Key transportation and communication lines cross the region. The Delta Region is home to dozens of islands with highly productive farms that have subsided to elevations as much as 25 feet below sea level. Jeffrey Mount, director of the Center for Integrated Watershed Science and Management at the University of California at Davis, said in a recent interview with MSNBC, "The chances of a catastrophic flood occurring in the Sacramento-San Joaquin Delta sometime in the next 50 years are about two out of three." He called Sacramento, which is only protected to a 1-in-80 year flood by its levees, "the most at-risk large metropolitan area in the country, with less than half the protection that New Orleans had. It is at extreme risk due to levee failure and subsidence."" The most serious catastrophe for the levees in the Delta Region would be a major earthquake occurring during the dry season. Such a quake would allow salt water to intrude from San Francisco Bay, shutting off the fresh water supply for millions of Californians for months. Collapse of the levees during the wet season would be less devastating, as water pressure from the relatively high flow rates of the Sacramento and San Joaquin Rivers would keep salt water from intruding into the Delta Region. There are no good solutions to California's Delta Region water vulnerabilities, but a new $10 billion dollar canal that would route fresh water around the region is being proposed as a possible way Califoria could avoid losing its fresh water supply if a catatrophic failure of the Delta Region levees allowed salt water intrusion to occur.

A 2009 study by the California Department of Water Resources concluded:

The Delta Region as it exists today is unsustainable. Seismic risk, high water conditions, sea level rise and land subsidence threaten levee integrity. A seismic event is the single greatest risk to levee integrity in the Delta Region. If a major earthquake occurs, levees would fail and as many as 20 islands could be flooded simultaneously. This would result in economic costs and impacts of $15 billion or more. While earthquakes pose the greatest risk to Delta Region levees, winter storms and related high water conditions are the most common cause of levee failures in the region. Under business-as-usual practices, high water conditions could cause about 140 levee failures in the Delta over the next 100 years. Multiple island failures caused by high water would but could still be extensive and could cause approximately $8 billion or more in economic costs and impacts. Dry-weather levee failures [also called sunny-day events] unrelated to earthquakes, such as from slumping or seepage, will continue to occur in the Delta about once every seven years. Costs to repair a single island flooded as the result of a dry-weather levee failure are expected to exceed $50 million. The risk of flooding in the Delta Region will only increase with time if current management practices are not changed. By the year 2100, Delta levee failure risks due to high water conditions will increase by 800 percent. The risk of levee failure from a major earthquake is projected to increase by 93 percent during the same period.


The ARkStorm scenario and Great Flood of 1862 are discussed in much more detail by weather historian Christopher C. Burt in his latest post.


Figure 2. Levee failure on the Upper Jones Tract in the Delta Region on June 4, 2004. Image credit: California Department of Water Resources. A 1997 flood in the Delta Region did $510 million damage, damaged or destroyed 32,000 homes and businesses, and left 120,000 homeless.

Wilma pounding New Zealand; Australia eyes two potential new tropical cyclones
With February nearly upon us, the traditional peak of the Southern Hemisphere tropical cyclone season is here. Activity has picked up markedly this week, with the formation of the year's first two Category 4 tropical cyclones, Tropical Cyclone Wilma and Tropical Cyclone Bianca. Wilma passed over American Samoa as a strong tropical storm, and hit Tonga as a Category 3 storm, causing substantial damage to the islands, but no deaths or injuries. Wilma is currently pounding New Zealand's North Island with heavy rains and strong winds, and is the strongest tropical cyclone to affect that country in fourteen years, according to weatherwatch.co.nz. Tropical Cyclone Bianca is expected to skirt the west coast of Australia over the next few days and rapidly weaken, but could bring heavy rains to the coast near Perth when it makes landfall on Sunday as a tropical storm. Of much greater concern for Australia are two potential tropical cyclones that could hit the flood-ravaged state of Queensland next week. Both the European Center and GFS models predict that the remains of Tropical Cyclone Anthony will regenerate into a tropical storm and hit Queensland early next week. A second and potentially more powerful storm is forecast by the European model to form next week in the islands to the east of Australia, and threaten Queensland at the end of the week. The GFS model has backed off on its prediction of such a storm forming. If the cyclone were to form, it would be a serious blow for Queensland, which is struggling to recover from record floods. As reported in the latest Bureau of Meteorology climate statement and flood summary, the past four months (September - December) have been the rainiest such period in Queensland's history, and the resulting flooding disaster has been Australia's most expensive natural disaster in history.


Figure 3. Tropical Cyclone Bianca, the globe's second major tropical cyclone of 2011, as seen at 06:30 GMT on January 28, 2011 by NASA's Aqua satellite. Biana is expected to rapidly weaken and hit the Australian coast near Perth as a tropical storm on Sunday. Image credit: NASA.

Have a great weekend, and I'll be back Monday with a new post.

Jeff Masters

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Quoting Patrap:


yeah,,maybe in dat Nordic slang no one would notice?


Jeg trodde aldri av det. Hvordan om dritt sekk
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A core looks like it may be trying to mature. Too bad there wasn't a better pass.

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Quoting washingtonian115:
I'd suspect you'd come out at this time of night.How are you? :)


I have a slight cold but it's only a minor nuisance. Yourself?
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Community Member Blogs
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Could someone tell me if this blog had a directory and where I might locate it?
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Quoting KoritheMan:


I always enjoy the summer. Winter can bite, here.
I'd suspect you'd come out at this time of night.How are you? :)
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Too bad it's a family blog. I could do a lot with that line.

Maybe I should unignore Grothar and find out what he's talking about.
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Yasi forecasted with a 18 ft Surge along a mostly N to S stretch with a lotta bays and inlets could be problematic for them.


The Surge Height May increase as well,,as a 200Kph Cyclone is Possible.

Size matters as well to Impact..exponentially.


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Quoting Grothar:


Too bad it's a family blog. I could do a lot with that line.



Bring it, Sonny.


Are you old enough to be up this late?
Member Since: July 23, 2010 Posts: 1 Comments: 12414
Member Since: Posts: Comments:
Quoting Patrap:
The Directory does hold some surprises Ive noticed today.

Arches and a Big River come to mind.


MPR.


Wow.
Member Since: July 23, 2010 Posts: 1 Comments: 12414
Quoting Grothar:


Too bad it's a family blog. I could do a lot with that line.


yeah,,maybe in dat Nordic slang no one would notice?
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Quoting Patrap:
Who is Ping and who is Pong...?

So we can set the archive right


Too bad it's a family blog. I could do a lot with that line.
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...Wise are you,who seek da Directory.

Ummm Yoda Hungry,,needs to make Rice for Gumbo he does..
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Quoting VAbeachhurricanes:


dude it was sarcasm...

For some people the cup is half full ... for others, half empty.
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Quoting VAbeachhurricanes:


How when one company that is run by conservatives does something wrong it means all conservatives are planet hating, evil people.
Like Enron?
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Quoting MiamiHurricanes09:
REMARKS:
310300Z POSITION NEAR 13.7S 163.6E.
TROPICAL CYCLONE (TC) 11P, LOCATED APPROXIMATELY 1100 NM EAST OF
CAIRNS, AUSTRALIA, HAS TRACKED WESTWARD AT 16 KNOTS OVER THE PAST
SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A
RAPIDLY CONSOLIDATING SYSTEM WITH TIGHTLY-CURVED BANDING WRAPPING
INTO A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER. ANIMATED WATER
VAPOR IMAGERY DEPICTS EXCELLENT RADIAL OUTFLOW. THE CURRENT
INTENSITY IS BASED ON DVORAK ESTIMATES OF 65 KNOTS FROM KNES AND
PGTW. TC 11P IS TRACKING ALONG THE NORTHERN PERIPHERY OF A DEEP
SUBTROPICAL RIDGE (STR) POSITIONED TO THE SOUTH. THE SYSTEM IS
EXPECTED TO TRACK WEST-SOUTHWESTWARD THROUGH TAU 72. THE STR IS
EXPECTED TO MAINTAIN THROUGH THE PERIOD BUT WILL SHIFT EAST AND RE-
ORIENT AS A MIDLATITUDE SHORTWAVE TROUGH DEEPENS OVER CENTRAL
AUSTRALIA AFTER TAU 72. THIS WILL ALLOW THE SYSTEM TO TURN
SOUTHWESTWARD AFTER MAKING LANDFALL NEAR TAU 72. THE AVAILABLE MODEL
GUIDANCE IS IN EXCEPTIONALLY CLOSE AGREEMENT THROUGH TAU 120,
THEREFORE, THERE IS GOOD CONFIDENCE IN THE FORECAST TRACK, WHICH IS
BASED LARGELY ON THE MODEL CONSENSUS. TC 11P HAS RAPIDLY INTENSIFIED
OVER THE PAST 24 HOURS, INCREASING FROM 35 TO 65 KNOTS, AND IS
EXPECTED TO INTENSIFY AT A 20-30 KNOT RATE PER DAY THROUGH
TAU 48, PEAKING AT 115 KNOTS NEAR TAU 48. TC 11P IS FORECAST TO MAKE
LANDFALL AS A 100+ KNOT, LARGE SYSTEM. TC 11P SHOULD DISSIPATE OVER
LAND BY TAU 96.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 310000Z IS 18
FEET. NEXT WARNINGS AT 311500Z AND 010300Z.//
NNNN


That's exactly what I've been afraid of...
Member Since: Posts: Comments:
Who is Ping and who is Pong...?

So we can set the archive right
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Quoting Patrap:
The Directory does hold some surprises Ive noticed today.

Arches and a Big River come to mind.



Got it.

Decoded.

System checking.
Member Since: July 23, 2010 Posts: 1 Comments: 12414
Quoting Patrap:
The Directory does hold some surprises Ive noticed today.

Arches and a Big River come to mind.


Is this is a riddle,Pat, I'll have to round up a few more brain cells....lol.....
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Quoting misanthrope:


Wow, guess we're going to have to start calling you Saint A-hole then.

Just wondering, aren't you the same guy who claimed that he doesn't trash anyone, ever? That is, before you called the Atmo Science facullty at A&M a bunch of alarmists. Or maybe an alarmist is a good thing to call an atmospheric scientist?

Not sure why you choose to lie about things that are so obviously untrue - it just seems to be your way. Right BJ?

? No, I said they were anything but.

It was right there in clear text. Look back, if you want.

My memory isn't good enough to lie...
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Quoting GeoffreyWPB:

Wow! Thanks. That's just about the whole movie right there!
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The Directory does hold some surprises Ive noticed today.

Arches and a Big River come to mind.
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Quoting EYEStoSEA:


Maybe they'll be back soon...hope so :)



I do, as well.
Member Since: July 23, 2010 Posts: 1 Comments: 12414
Quoting EYEStoSEA:


Was wondering about K-Man and KanKunKid...always enjoyed them, too.
I guess some people are only on during hurricane season.And during off season well you know all those rumors about the global warming debates?.Well I guess that's whats keping them away.
Quoting PSLFLCaneVet:


It's nice when no sweating is involved.

I always enjoy the winter. Summer can bite, here.
Summer can reek hear.Especially when your in rock creek park.You can smell the swamp.However I still love summer!
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Quoting Patrap:
The Purge was swift for some as of late.

Admin gave out er,,Bullet Points for some the past week.

permanent for some Handles.

This Blog has been banned by WunderBlogAdmin



Interesting, Pat.

Thanks.
Member Since: July 23, 2010 Posts: 1 Comments: 12414
Quoting PSLFLCaneVet:



Agreed.


Maybe they'll be back soon...hope so :)
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Quoting KoritheMan:


I always enjoy the summer. Winter can bite, here.


LOL, just a function of geography.

Evening, K.
Member Since: July 23, 2010 Posts: 1 Comments: 12414
Quoting EYEStoSEA:


Was wondering about K-Man and KanKunKid...always enjoyed them, too.



Agreed.
Member Since: July 23, 2010 Posts: 1 Comments: 12414
Quoting washingtonian115:
Hmmm I haven't seen DestinJeff around latley,or is he only around during hurricane season?.



I'd like to know what's keeping him from being on, as well.

Hear that, DJ?

Come on back, the waters need your special sauce.


LOL
Member Since: July 23, 2010 Posts: 1 Comments: 12414
Quoting PSLFLCaneVet:


I always enjoy the winter. Summer can bite, here.


I always enjoy the summer. Winter can bite, here.
Member Since: Posts: Comments:
The Purge was swift for some as of late.

Admin gave out er,,Bullet Points for some the past week.

permanent for some Handles.

This Blog has been banned by WunderBlogAdmin
Member Since: Posts: Comments:
REMARKS:
310300Z POSITION NEAR 13.7S 163.6E.
TROPICAL CYCLONE (TC) 11P, LOCATED APPROXIMATELY 1100 NM EAST OF
CAIRNS, AUSTRALIA, HAS TRACKED WESTWARD AT 16 KNOTS OVER THE PAST
SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A
RAPIDLY CONSOLIDATING SYSTEM WITH TIGHTLY-CURVED BANDING WRAPPING
INTO A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER. ANIMATED WATER
VAPOR IMAGERY DEPICTS EXCELLENT RADIAL OUTFLOW. THE CURRENT
INTENSITY IS BASED ON DVORAK ESTIMATES OF 65 KNOTS FROM KNES AND
PGTW. TC 11P IS TRACKING ALONG THE NORTHERN PERIPHERY OF A DEEP
SUBTROPICAL RIDGE (STR) POSITIONED TO THE SOUTH. THE SYSTEM IS
EXPECTED TO TRACK WEST-SOUTHWESTWARD THROUGH TAU 72. THE STR IS
EXPECTED TO MAINTAIN THROUGH THE PERIOD BUT WILL SHIFT EAST AND RE-
ORIENT AS A MIDLATITUDE SHORTWAVE TROUGH DEEPENS OVER CENTRAL
AUSTRALIA AFTER TAU 72. THIS WILL ALLOW THE SYSTEM TO TURN
SOUTHWESTWARD AFTER MAKING LANDFALL NEAR TAU 72. THE AVAILABLE MODEL
GUIDANCE IS IN EXCEPTIONALLY CLOSE AGREEMENT THROUGH TAU 120,
THEREFORE, THERE IS GOOD CONFIDENCE IN THE FORECAST TRACK, WHICH IS
BASED LARGELY ON THE MODEL CONSENSUS. TC 11P HAS RAPIDLY INTENSIFIED
OVER THE PAST 24 HOURS, INCREASING FROM 35 TO 65 KNOTS, AND IS
EXPECTED TO INTENSIFY AT A 20-30 KNOT RATE PER DAY THROUGH
TAU 48, PEAKING AT 115 KNOTS NEAR TAU 48. TC 11P IS FORECAST TO MAKE
LANDFALL AS A 100+ KNOT, LARGE SYSTEM. TC 11P SHOULD DISSIPATE OVER
LAND BY TAU 96.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 310000Z IS 18
FEET. NEXT WARNINGS AT 311500Z AND 010300Z.//
NNNN

Member Since: Posts: Comments:
Quoting JFLORIDA:
In 1999, a federal jury found that Koch Industries had stolen oil from government and American Indian lands, had lied about its purchases more than 24,000 times

Classy.

Yes, a bunch of real Americans, those Koch Brothers are. But you have to hand it to them; they donated $48 million between 1997 and 2008 toward GW denialist groups, money that was well spent judging by some of the comments seen here and elsewhere. Can't blame them for protecting their interests in fossil fuels, though; much of their $35 billion fortune comes from oil and coal, so they're the last ones you can expect to be honest about climate science.
Member Since: November 8, 2009 Posts: 4 Comments: 13461
Quoting washingtonian115:
Hmmm I haven't seen DestinJeff around latley,or is he only around during hurricane season?.


Was wondering about K-Man and KanKunKid...always enjoyed them, too.
Member Since: Posts: Comments:
Quoting washingtonian115:
When it get's to around 45 degres that's when most of the joggers start coming out.And the heavy coats are replaced with light jackets.


It's nice when no sweating is involved.

I always enjoy the winter. Summer can bite, here.
Member Since: July 23, 2010 Posts: 1 Comments: 12414
Hmmm I haven't seen DestinJeff around latley,or is he only around during hurricane season?.
Member Since: Posts: Comments:
Quoting VAbeachhurricanes:


yeah, just seems after a good snow, the sky is so clear, and sun so bright its just beautiful. Love just walking around the neighborhood shoveling driveways makin a bit of cash



LOL, agreed.
Member Since: July 23, 2010 Posts: 1 Comments: 12414
Quoting PSLFLCaneVet:



Nice.

I used to drive around in MN with the windows down, if the sun was out and it got to 40.
When it get's to around 45 degres that's when most of the joggers start coming out.And the heavy coats are replaced with light jackets.
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Quoting twincomanche:


Your idiot post speaks for itself.

Move on there is nothing of interest here.


dude it was sarcasm...
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Quoting PSLFLCaneVet:



Nice.

I used to drive around in MN with the windows down, if the sun was out and it got to 40.


yeah, just seems after a good snow, the sky is so clear, and sun so bright its just beautiful. Love just walking around the neighborhood shoveling driveways makin a bit of cash
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Live Long and Prosper..

And good Luck on the tests too.
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Alright got a physics and linear calc test to study for... im out you all have a great evening.
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Quoting twincomanche:


Go away. You are rude.
This has to be the best damn comment of the day.
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Quoting VAbeachhurricanes:


Hey, i shovel snow in just a t-shirt and sweatpants when the sun is out. You guys can get over it :P



Nice.

I used to drive around in MN with the windows down, if the sun was out and it got to 40.
Member Since: July 23, 2010 Posts: 1 Comments: 12414
Quoting twincomanche:


And this has to do with what?


How when one company that is run by conservatives does something wrong it means all conservatives are planet hating, evil people.
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Quoting VAbeachhurricanes:


btw thanks for taking mcnabb off our hands.
Love, Eagles Fans :D
I'm not even sure why they gave him that contract.It was a mistake I tell ya.
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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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