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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1004. Skyepony (Mod)
Quoting KoritheMan:


An additional piece of good news is that large hurricanes like Yasi typically have a much harder time intensifying, because there is greater mass to spin up.

Still, all good things must come to an end, and I'd imagine a pretty significant storm surge is likely along the Queensland coast due to the possibility that this system will grow even larger and intensify further.


It's been amazing how fast Yasi has come to be. It was declared an invest 48hrs ago..


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Quoting EYEStoSEA:
1000,1001,1002
It brings back memories as a kid,with all the thundrstorms.It also reminds me of Poltergist.
Member Since: August 14, 2010 Posts: 10 Comments: 16437
1002. Patrap
Member Since: July 3, 2005 Posts: 421 Comments: 127636
1001. Patrap
Quoting Grothar:
Actually, it is better to insult someone in German. It scares them more. If one does it in Norwegian or Swedish, it sounds like were singing to them.


.."Its not unusual to be,..Loved by anyone"..
Member Since: July 3, 2005 Posts: 421 Comments: 127636
Quoting PSLFLCaneVet:



Time for me to hit the rack.

Thanks, folks.

"Be excellent to each other."
G'Nite.
And, good advice.
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Quoting Grothar:
Actually, it is better to insult someone in German. It scares them more. If one does it in Norwegian or Swedish, it sounds like were singing to them.
Cake recipes sound vicious in German...
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Storm Relative 16km Microwave-Based Total Precipitable Water Imagery

To compliment the 16km storm relative TPW product listed above, water vapor imagery, with a spectral weight near 6.7 um is displayed with the same resolution, projection, and storm relative geometry. Water Vapor imagery is helpful in determining the location of deep convection, indicated by the coldest pixels, relative upper-level moisture content in areas devoid of deep convection, and upper-level atmospheric motions via animation of these images. The imagery can be used to infer favorable and unfavorable regions of environmental forcing (e.g., areas of increased vertical wind shear or atmospheric subsidence).


Yasi


Time of Latest Image: 201101310047

Member Since: July 3, 2005 Posts: 421 Comments: 127636
Quoting PSLFLCaneVet:



Time for me to hit the rack.

Thanks, folks.

"Be excellent to each other."


and goodnight to you.....
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Quoting bappit:
Atmo orifice?
At me?

Hehe, I like it!
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Actually, it is better to insult someone in German. It scares them more. If one does it in Norwegian or Swedish, it sounds like were singing to them.
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994. Skyepony (Mod)
Quoting JFLORIDA:
Koch Brothers Protest: 25 Arrested At California Conservative Meeting some protesters crossed the street to the Rancho Las Palmas Resort.

Deputies in riot gear arrested them without incident when they refused to leave the area.
_______________________________________________________



I've been keeping up with this. Sadly also the root & funding for the Tea Party. That environmental wrecking history there was tame when compared to the history of how Koch has puppet stringed the govt of this country. Sudden title wave of backlash in the media. Boycotts of their products.. Angel Soft, Brawny, Dixie, Mardi Gras, Quilted Northern, Soft n Gentle, Zee, Sparkle, Vanity Fair napkins, Georgia Pacific building products, Lycra & Stainmaster. They've been recently booed in public & well they're hated enough for Greenpeace to make a blimp about the matter..
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Time for me to hit the rack.

Thanks, folks.

"Be excellent to each other."
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1000,1001,1002
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2km Storm Relative IR Imagery with BD Enhancement Curve


The same infrared imagery shown in the earth relative framework is displayed in a storm relative framework, with a 2km resolution and enhanced with the "BD Curve" which is useful for directly inferring intensity via the Dvorak Enhanced IR (EIR) technique. Scaling is provided by two lightly hatched circles around the center. The two circles have radii of 1 and 2 degrees latitude, respectively.

Yasi


Time of Latest Image: 201101310332

Member Since: July 3, 2005 Posts: 421 Comments: 127636
That might be worse in the Google translation than the actual meaning.
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Quoting GeoffreyWPB:
Grothar er en tosk.


Og du også! Jeg skall dritte i nå.
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Quoting bappit:
I feel more like I do today than I did yesterday.
????
Member Since: August 14, 2010 Posts: 10 Comments: 16437
He's a bad influence. I had to do what needed to be done to protect myself.
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Quoting Levi32:


I also see the strong presence of some dry air. The banded structure and equatorward outflow are excellent, but the circulation remains laced with dry air, especially on the south side due to upper convergence infringing on the system. That said, the upper-level environment will likely improve gradually over the next couple days.



An additional piece of good news is that large hurricanes like Yasi typically have a much harder time intensifying, because there is greater mass to spin up.

Still, all good things must come to an end, and I'd imagine a pretty significant storm surge is likely along the Queensland coast due to the possibility that this system will grow even larger and intensify further.
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I feel more like I do today than I did yesterday.
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.."tomorrow's just da future yesterday"..
Member Since: July 3, 2005 Posts: 421 Comments: 127636
Atmo orifice?
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Quoting GeoffreyWPB:


Maybe that's why he put you on ignore :)


Go post a video! You odd little person. (LOL)
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Grothar er en tosk.
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Quoting KEEPEROFTHEGATE:
00z GFS update up next



Evening, Keeper.
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....I give up few secrets.

Dat one stays in da Vault.

Member Since: July 3, 2005 Posts: 421 Comments: 127636
Quoting Levi32:


I also see the strong presence of some dry air. The banded structure and equatorward outflow are excellent, but the circulation remains laced with dry air, especially on the south side due to upper convergence infringing on the system. That said, the upper-level environment will likely improve gradually over the next couple days.

Thank godness.I hope dry air continues to pull this beast down.
Member Since: August 14, 2010 Posts: 10 Comments: 16437
00z GFS update up next
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Quoting Patrap:
Jeg trodde virkelig at du var litt interessert i meg som person,


Jeg tror ikke slik. LOL

(How did you do that. Those internet translations always come out funny. That was perfect.)
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Quoting bappit:
Hmmmm, was the Google translate close?
Google translate hate me.It never translates anything right for me,but a boat load of crap.
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Ooofh..


The Water Planet cranks out one to be wary of.


Time of Latest Image: 201101310332
Member Since: July 3, 2005 Posts: 421 Comments: 127636
Quoting 1900hurricane:
A core looks like it may be trying to mature. Too bad there wasn't a better pass.



I also see the strong presence of some dry air. The banded structure and equatorward outflow are excellent, but the circulation remains laced with dry air, especially on the south side due to upper convergence infringing on the system. That said, the upper-level environment will likely improve gradually over the next couple days.

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972. HadesGodWyvern (Mod)
Fiji Meteorological Services
Tropical Disturbance Advisory #8
TROPICAL CYCLONE YASI (09F)
12:00 PM FST January 31 2011
=================================

At 0:00 AM UTC, Tropical Cyclone Yasi, Category Two (980 hPa) located at 13.6S 164.2E has 10 minute sustained winds of 55 knots. The cyclone is reported as moving west at 14 knots. Position FAIR based on multispectral visible/infrared imagery with animation and peripheral surface observations.

Storm Force Winds
================
30 NM from the center

Gale Force Winds
================
150 NM from the center in eastern semi-circle
80 NM from the center in northwestern quadrant
90 NM from the center in southwestern quadrant

Overall organization has improved significantly past 24 hours. Convection remains persistent in the last 6 hours. Primary band wrapping around the low level circulation center. System lies along a surface trough and under a diffluent region in a weak sheared environment. Cyclonic circulation extends to 500 HPA. Outflow good to north and south and developing elsewhere. System is steered westward mainly by an easterly deep layer mean flow.

Dvorak assessment based on 1.3 LOG10 wrap yeilding DT=4.0 MET=4.0 PT=4.0

Dvorak Intensity: T4.0/4.0/D1.5/24HRS.

Global models further developing the cyclone and maintaining a westward track.

Forecast and Intensity
=======================
12 HRS: 14.0S 161.3E - 70 knots (CAT 3)
24 HRS: 14.4S 158.4E - 85 knots (CAT 3)
48 HRS: 16.4S 153.1E - 90 knots (CAT 4)

The next Tropical Disturbance Advisory from Fiji Meteorological Services will be issued at around 8:30 AM UTC..
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Quoting KoritheMan:


Go for it! He sounds like he'd be a good asset.
I've already sent him the message.I think he'll be an awesome addition to the blog.
Member Since: August 14, 2010 Posts: 10 Comments: 16437
Hmmmm, was the Google translate close?

Edit: close enough.
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Quoting GeoffreyWPB:


Maybe that's why he put you on ignore :)



LOL
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Quoting bappit:

"I never thought of it. How about c**p bag"


Close literal translation, but it is a slang expression which means something else. You know like what people have been calling each other here on the blog tonight.
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Quoting Grothar:


Are you kidding. I'm old enough to stay up for the next 5 years. How you doing PSL?



You know I am.

Salutations, friend.


Exceedingly well, thank you.

You?
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Jeg trodde virkelig at du var litt interessert i meg som person,
Member Since: July 3, 2005 Posts: 421 Comments: 127636
Quoting Grothar:


Why would you have me on ignore? I even commented on what a nice caliphrodae you had.


Maybe that's why he put you on ignore :)
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Quoting Grothar:


Why would you have me on ignore? I even commented on what a nice caliphrodae you had.



Word of the Day nominee.

Kudos!
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Quoting PSLFLCaneVet:



Bring it, Sonny.


Are you old enough to be up this late?


Are you kidding. I'm old enough to stay up for the next 5 years. How you doing PSL?
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Quoting Grothar:


Jeg trodde aldri av det. Hvordan om dritt sekk

"I never thought of it. How about c**p bag"
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yer welcome.

The site menu is at the top of every Wunderground page
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Quoting washingtonian115:
Okay folks.Get ready for what I'm about to tell you.I'm going to see If I can invite one of the best known storm chaser's to the blog,and check it out His name is Micheal Laca a.k.a vmax on youtube.He films great weather videos.I have him as a friend/subscriber on youtube.


Go for it! He sounds like he'd be a good asset.
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Quoting bappit:
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.


Why would you have me on ignore? I even commented on what a nice caliphrodae you had.
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Quoting KoritheMan:


I have a slight cold but it's only a minor nuisance. Yourself?
My alergies have calm down for now that is.But I've had a wonderful sunday.Temps this time weren't freezing out side like hey have been most winter.
Member Since: August 14, 2010 Posts: 10 Comments: 16437
Tropical Cyclone Track and Intensity Forecasts and Guidance



Disclaimer: The tropical cyclone objective aids displayed on this web site are collected from multiple forecast centers and may or may not be the most
current data available to the operational forecast centers. The MIT tropical meteorology group obtains these forecasts for research purposes and assumes
no responsibility for their use in the forecasting of tropical cyclones. Concerned individuals or organizations should confirm these forecasts with
official sources.

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Quoting Patrap:
Community Member Blogs


Well..DUH...now I feel really senile....thank you ;}
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Okay folks.Get ready for what I'm about to tell you.I'm going to see If I can invite one of the best known storm chaser's to the blog,and check it out His name is Micheal Laca a.k.a vmax on youtube.He films great weather videos.I have him as a friend/subscriber on youtube.
Member Since: August 14, 2010 Posts: 10 Comments: 16437
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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About

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