Red River rising: 18th consecutive year of flooding--why?

By: Dr. Jeff Masters , 03:08 PM GMT am 19. März 2010

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The Red River at Fargo, North Dakota continues to rise, with a peak expected Sunday at the 4th highest flood level observed in the past century. "Major" flood level is 30 feet, which the river surpassed on Wednesday, and the river is expected to crest near 38 feet on Sunday, just 2.8 feet below the record set last year. Flood stage is eighteen feet, and the Red River has now reached flood stage at Fargo for eighteen consecutive years, according to the U.S. Army Corps of Engineers. Prior to this remarkable stretch of flooding (which began in 1993), the river flooded in just 29 of 90 years. This year's flood is rated as somewhere between a 50-year and 100-year flood. Last year's record flood was a 100-year flood. The U.S. Army Corps of Engineers lists the 10-year flood level for the Red River at Fargo to be 10,300 cubic feet per second. A 10-year flood, historically, has a 10% chance of occurring in a given year. In the last twenty years, the Red River has had eight 10-year floods--one every 2.5 years, on average. This year is the fourth year out of the past five with a 10-year flood. Clearly, flooding has increased significantly along the Red River over the past twenty years.


Figure 1. Current and forecast flood stage for the Red River of the North at Fargo, ND. You can access images like these using our wundermap for Fargo with the "USGS River" layer turned on. Click on the icon for USGS station 05054000, then hit the "click for graph" link.

Reasons for flooding: landform factors
According the U.S. Geological Survey, the unique landform characteristics of the Red River Valley make it highly susceptible to flooding. These factors include:

1) A relatively shallow and meandering river channel--a shallow channel holds less water and the meandering can cause flow to slow down as the channel makes its turns, causing over-bank flooding.

2) A gentle slope (averaging 0.5 to 1.5 feet per mile) that inhibits channel flow and encourages overland flooding or water "ponding" (especially on even, saturated ground) in the basin.

3) The northerly direction of flow--flow in the Red River travels from south (upstream) to north (downstream). The direction of flow becomes a critical factor in the spring when the southern (upstream) part of the Red River has thawed and the northern (downstream) part of the channel is still frozen. As water moves north toward the still frozen river channel, ice jams and substantial backwater flow and flooding can occur.


Figure 2. Peak flow of the Red River at Fargo, North Dakota through time. The two largest flow rates occurred last year (2009), and in 1997. The projected crest for Sunday (red circle) would be fourth greatest flood since reliable records began in 1901. Image credit: U.S. Geological Survey.

Reasons for this year's flood: highly unfavorable weather conditions
The USGS also cites five weather factors that can act to enhance flooding along the Red River. All five of these factors occurred to a significant degree this year:

1) Above-normal amounts of precipitation in the fall of the year that produce high levels of soil moisture, particularly in flat surface areas, in the basin. North Dakota had its 22nd wettest fall in the 115-year record in 2009.

2) Freezing of saturated ground in late fall or early winter, before significant snowfall occurs, that produces a hard, deep frost that limits infiltration of runoff during snowmelt. Fargo had a November that was much warmer than average, followed by a sudden plunge to below-zero temperatures by the second week of December. This froze the saturated ground to a great depth.

3) Above-normal winter snowfall in the basin. North Dakota had a top 15% winter for precipitation, with the period December 2009 - February 2010 ranking 15th wettest in the past 115 years.

4) Above-normal precipitation during snowmelt. Precipitation for March 1 - 18 has been 1.41", compared to the average of 0.61".

5) Above-normal temperatures during snowmelt. High temperatures in Fargo have averaged 6°F warmer than normal for March 1 - 18.

Urbanization increases flooding
Urbanization has had a major impact on increasing flooding not only along the Red River, but in every river basin in the U.S. Many cities and developed areas are located in flood plains next to major rivers and their tributaries. Highways, streets, parking lots, sidewalks, and buildings now cover large areas of the ground that used to absorb excess rain water and slow the rate at which run-off from precipitation and melting snow reached rivers. By developing large portions of our flood plains, run-off now reaches rivers more quickly, generating higher floods.

Building levees and flood defenses increases flood peaks
Defending ourselves against floods has made floods worse. Every time a new levee is built, or an old floodwall raised in height to prevent overtopping, more and more water is forced into the river bed, which raises the height of the flood. Flood waters that used to be able to spread out over their natural flood plains are now forbidden from spilling out over newly developed land in flood plains. For example, proposed improvements to the flood defense system in Fargo could cause a 4 - 10 inch rise in floods immediately downstream from the city, according to the Army Corps of Engineers.

Precipitation is increasing
As the climate warms, evaporation of moisture from the oceans increases, resulting in more water vapor in the air. According to the 2007 IPCC report, water vapor in the global atmosphere has increased by about 5% over the 20th century, and 4% since 1970. Satellite measurements (Trenberth et al., 2005) have shown a 1.3% per decade increase in water vapor over the global oceans since 1988. Santer et al. (2007) used a climate model to study the relative contribution of natural and human-caused effects on increasing water vapor, and concluded that this increase was "primarily due to human-caused increases in greenhouse gases". This was also the conclusion of Willet et al. (2007). This increase in water vapor has very likely led to an increase in global precipitation. For instance, over the U.S., where we have very good precipitation records, annual average precipitation has increased 7% over the past century (Groisman et al., 2004). Precipitation over the Red River drainage basin increased by about 10 - 20% during the 20th Century (Figure 3.) The same study also found a 14% increase in heavy (top 5%) and 20% increase in very heavy (top 1%) precipitation events over the U.S. in the past century. These are the type of events most likely to cause flooding. Kunkel et al. (2003) also found an increase in heavy precipitation events over the U.S. in recent decades, but noted that heavy precipitation events were nearly as frequent at the end of the 19th century and beginning of the 20th century, though the data is not as reliable back then.


Figure 3. Change in precipitation over the U.S. between 1900 - 2000, from the U.S. Cooperative network. Precipitation in the Red River drainage area increased by 10 - 20% over the 20th century. Image credit: Contemporary Changes of the Hydrological Cycle over the Contiguous United States: Trends (Groisman et al., 2002).

The future of flooding
As the population continues to expand, development in flood plains and construction of new levees and flood protection systems will continue to push floods to higher heights. With global warming expected to continue and drive ever higher precipitation amounts--falling preferentially in heavy precipitation events--it is highly probable that flooding in the Red River Valley--and over most of the northern 2/3 of the U.S. where precipitation increases are likely--will see higher and more frequent floods. With these higher and more frequent floods comes the increased risk of multi-billion dollar disasters, when a record flood event overwhelms flood defenses and inundates huge areas of developed flood plains. Obviously, we need to make smart decisions to limit development in flood plains to reduce the cost and suffering of these future flooding disasters.

References
Kunkel, K. E., D. R. Easterling, K. Redmond, and K. Hubbard, 2003, "Temporal variations of extreme precipitation events in the United States: 1895.2000", Geophys. Res. Lett., 30(17), 1900, doi:10.1029/2003GL018052.

Groisman, P.Y., R.W. Knight, T.R. Karl, D.R. Easterling, B. Sun, and J.H. Lawrimore, 2004, "Contemporary Changes of the Hydrological Cycle over the Contiguous United States: Trends Derived from In Situ Observations," J. Hydrometeor., 5, 64.85.

Milly, P.C.D., R.T. Wetherald, K.A. Dunne, and T.L.Delworth, Increasing risk of great floods in a changing climate", Nature 415, 514-517 (31 January 2002) | doi:10.1038/415514a.

Santer, B.D., C. Mears, F. J. Wentz, K. E. Taylor, P. J. Gleckler, T. M. L. Wigley, T. P. Barnett, J. S. Boyle, W. Brüggemann, N. P. Gillett, S. A. Klein, G. A. Meehl, T. Nozawa, D. W. Pierce, P. A. Stott, W. M. Washington, and M. F. Wehner, 2007, "Identification of human-induced changes in atmospheric moisture content", PNAS 2007 104: 15248-15253.

Trenberth, K.E., J. Fasullo, and L. Smith, 2005: "Trends and variability in column-integrated atmospheric water vapor", Climate Dynamics 24, 741-758.

Willett, K.M., N.P. Gillett, P.D. Jones, and P.W. Thorne, 2007, "Attribution of observed surface humidity changes to human influence", Nature 449, 710-712 (11 October 2007) | doi:10.1038/nature06207.

Links
A good way to track the flooding event is to use our wundermap for the Red River with the USGS River layer turned on.

The Fargo Flood webpage of North Dakota State University, Fargo, has some excellent links.

I'll have a new post on Monday or Tuesday.

Jeff Masters

Red River Flood 2006 (mw25)
The water level of the Red River when I took this photo was 47.2 feet, 19.2 feet above flood stage and the 6th highest level in Grand Forks' history. The river is expected to crest at 47.4 feet on Wednesday morning. Luckily, no homes have been lost in the Grand Forks area as of yet due to the flooding.
Red River Flood 2006
Fargo Flood 2009 - Elm & 15th Ave. N. (tliebenow)
Picture says it all. Clay dike built to contain the Red River in North Fargo.
Fargo Flood 2009 - Elm & 15th Ave. N.

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459. Relix
Just chiming in to say Hi. Been wandering around the site but haven't commented in a long time. Seems like 2010 will be a rough ride.
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Quoting Jeff9641:


1 to 3" of rain expected Sunday afternoon and night with temps in the 80's today and tomorrow. I have a feeling that severe wx will be quite possible tomorrow after as dewpoints hit the mid 60's in C FL.

Morning jeff, I was thinking the same thing and NWS did say there is a slight chance of severe wx sunday night. Good to see you back on the blog.
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Quoting P451:


47 here in NJ. Hit 72 yesterday. Expecting more of the same. Hit the beach 2 days ago. No jacket, no shoes, 2 mile walk, no problem!

After this winter this is a very welcome early spring!

Morning, Hows the flooding up your way. Nice pics you had from your winter. Saw them here and on Blizz's blog.
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Morning All, Did someone say today was the first day of spring? I live in w c fl CRAZY!!!
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TROPICAL CYCLONE ADVICE NUMBER 15
Issued by the Bureau of Meteorology, Brisbane
Issued at 7:49pm EST on Saturday the 20th of March 2010

A Cyclone WARNING continues for coastal areas from Cardwell to Yeppoon and
inland to Hughenden, including Charters Towers and Clermont.

At 7:00 pm EST Severe Tropical Cyclone Ului, Category 3 was estimated to be
190 kilometres northeast of Mackay and
405 kilometres east southeast of Townsville and
moving west southwest at 31 kilometres per hour.

The cyclone is expected to cross the coast between Ayr and Mackay, most likely
in the Proserpine region as a severe tropical cyclone early Sunday. The cyclone
is then expected to weaken inland later on Sunday.

VERY DESTRUCTIVE wind gusts to 200 km/hr near the cyclone centre may affect
coastal and island communities in the threatened area late tonight and early
Sunday.

DAMAGING winds are expected to develop between Cardwell and Yeppoon this
evening, then extend to adjacent inland parts during Sunday.

TIDES between Bowen and St Lawrence may rise to just above the highest tide of
the year overnight with very rough seas and dangerous conditions along the
foreshore.

HEAVY RAINFALL and flooding are likely to develop about coastal and adjacent
inland areas between Bowen and St Lawrence early Sunday.

DANGEROUS SURF conditions are expected to continue about exposed beaches south
of the cyclone until later on Sunday. A separate Severe Weather Warning is
current for these conditions.

People in the path of the dangerous cyclone should stay calm and remain in a
secure shelter while the very destructive winds develop late tonight and early
Sunday. Do not venture outside if you find yourself in the eye of the cyclone as
winds may remain light for up to an hour - very destructive winds from a
different direction could resume at any time. Heed the advice and follow the
instructions of Police or State Emergency Service personnel.

People from Cardwell to Yeppoon and inland to Hughenden, including Charters
Towers and Clermont should complete preparations quickly and be prepared to
shelter in a safe place.
- Boats and outside property should now be secured.
- For cyclone preparedness and safety advice, visit Queensland's Disaster
Management Services
website [www.disaster.qld.gov.au].
- For emergency assistance call the Queensland State Emergency Service [SES] on
132 500 [for assistance with storm damage, rising flood water, fallen trees on
buildings or roof damage]

Details of Severe Tropical Cyclone Ului at 7:00 pm EST:
.Centre located near...... 20.1 degrees South 150.6 degrees East
.Location accuracy........ within 35 kilometres
.Recent movement.......... towards the west southwest at 31 kilometres per hour
.Wind gusts near centre... 205 kilometres per hour
.Severity category........ 3
.Central pressure......... 955 hectoPascals

The next advice will be issued by 9:00 pm EST Saturday 20 March.

Member Since: September 30, 2007 Posts: 9 Comments: 15977
I believe the flood problem began when they drained the wetlands that normally held excess water.
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447. ackee
Quoting altesticstorm10:
I give it a 100% chance that we see at least one storm forming in the Caribbean in late May through the end of June.
why u think that
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We have the Outer Bands of the Cyclone on radar,looking out toward the eyewall ,,its now in Working order from Australia.

256 km Mackay Radar Loop





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Ului Finding that warmer Shelf SST environment and is taking advantage of it as it heads towards a Landfall.





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Quoting Levi32:


The areas where storms are most likely to form, with blue being "likely", green being "more likely" and orange being "most likely", as shown in the legend. There are no orange areas in June, July, and November, because only a few storms form during those months. The white arrows show the prevailing storm tracks.








they may need to start adding ones for May and December lmao
Member Since: März 10, 2010 Posts: 1 Comments: 7874
Cyclone Ului radar loop

Ului looks on target for a landfall near Cannonvale, Queensland, at tropical storm intensity.

Quoting winter123:


I see that every year, but thanks for posting it as a reminder. The northeast really needs to pay attention in september as theres almost always a close call, or maybe a hit.


Yeah lol well they are a great illustration of where storms tend to form in certain months, thus we use them a lot when talking about that. The NHC has some nice climatology maps.
Member Since: November 24, 2005 Posts: 635 Comments: 26700
New radar will track Queensland cyclone



Friday, 19/03/2010

The threat of Cyclone Ului hitting the Central Queensland coast has forced the weather bureau to turn on a new radar two weeks early.

The Emerald radar is still being tested, mode but will be visible to the public this afternoon.

The regional director of the Queensland Bureau of Meteorology Jim Davidson, says it fills in a big black hole for farmers and graziers.

"We had Longreach to the west and Gladstone and Mackay on the coast to the east," he says.

"There were quite a large number of tracks in the Central Highlands which weren't under radar coverage, but under the new radar, that will all change."
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Quoting Levi32:


The areas where storms are most likely to form, with blue being "likely", green being "more likely" and orange being "most likely", as shown in the legend. There are no orange areas in June, July, and November, because only a few storms form during those months.








I see that every year, but thanks for posting it as a reminder. The northeast really needs to pay attention in september as theres almost always a close call, or maybe a hit.
Member Since: Juli 29, 2006 Posts: 28 Comments: 1802
Ului now visible on radar
Member Since: März 10, 2010 Posts: 1 Comments: 7874
Quoting doabarrelroll:


In this image the colored areas represent what? The areas where storms form?


The areas where storms are most likely to form, with blue being "likely", green being "more likely" and orange being "most likely", as shown in the legend. There are no orange areas in June, July, and November, because only a few storms form during those months. The white arrows show the prevailing storm tracks.






Member Since: November 24, 2005 Posts: 635 Comments: 26700
Quoting Patrap:


my of course..send it.

We always running out of that liquid here seems.

WHAT WAS THIS WEATHERMAN THINKING?



That is not thinking, that is wishing.
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Quoting Grothar:


Must have missed that one; probabaly working on my doctorate at La Sorbonne at the time. LOL What is good? Hey, I may send you some Mack-o if I am ever in the old neighborhood. Looks like a few on here could use some. Thanks for the laughs Pat.


my of course..send it.

We always running out of that liquid here seems.

WHAT WAS THIS WEATHERMAN THINKING?
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Quoting GeoffreyWPB:
Michael Rennie...that makes us even on Hindenberg!


What do you mean? I spelled it correctly. LOL
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Quoting Patrap:
Iron man cartoon from the sixties

Ahh,..Loved dat series,..LOL


Must have missed that one; probabaly working on my doctorate at La Sorbonne at the time. LOL What is good? Hey, I may send you some Mack-o if I am ever in the old neighborhood. Looks like a few on here could use some. Thanks for the laughs Pat.
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Michael Rennie...that makes us even on Hindenburg!
Member Since: September 10, 2007 Posts: 0 Comments: 11538
Iron man cartoon from the sixties

Ahh,..Loved dat series,..LOL
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Quoting GeoffreyWPB:
Grothar...you missed my post on Pat's new aviator...It's from Ironman 2...but my first response was "Klaatu barada nikto". Thought you would get a kick out of that!


Michel Rennie was so much better than the new one.
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426. JRRP

the SST near CV will cool a bit
i think


see you later
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425. xcool
hey
Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting Grothar:


Nice link Pat, mind if I bookmark it? Might may me look like I know what I am talking about. Whose site is it?


a blogger gave me the link..here.

I cant recall the handle,..maybe wpb
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Grothar...you missed my post on Pat's new aviator...It's from Ironman 2...but my first response was "Klaatu barada nikto". Thought you would get a kick out of that!
Member Since: September 10, 2007 Posts: 0 Comments: 11538
<>img src="" alt="" />
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Quoting Patrap:
Hyman Roth always made money for his partners.

And my father always respected Hyman Roth

Now if you'll excuse me I have to go check on the GFS.

www.canefever.com/links



Nice link Pat, mind if I bookmark it? Might may me look like I know what I am talking about. Whose site is it?
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Hyman Roth was a fictional character based on Myer Lanskey.
Member Since: September 10, 2007 Posts: 0 Comments: 11538
Quoting Patrap:
Hyman Roth always made money for his partners.

And my father always respected Hyman Roth

Now if you'll excuse me I have to go check on the GFS.

www.canefever.com/links



My father respected Hyman Roth, my father worked with Hyman Roth, but my father never trusted Hyman Roth!
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Quoting Chicklit:
Here's something for Patrap.
img src="" alt="" />


Hey Chicklit,can you find "In the Wee Small Hours of the Morning" from Sleepless in Seattle. It might put us all in a nice mood before beddy-bye.
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Hyman Roth always made money for his partners.

And my father always respected Hyman Roth

Now if you'll excuse me I have to go check on the GFS.

www.canefever.com/links

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ooohhhh...I lke dat one chicklit.
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Here's something for Patrap.
img src="" alt="" />
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Quoting Patrap:
.."You Broke my Heart Fredo"..

I've never known anyone using accuweather to be so subdued.

Is this guy a Blogger here?



Dallas - Ft. Worth, TX - Be advised for



That's because all you've ever seen is that one random guy who gets pretty wild on his local tv station. It speaks volumes that you were actually on Accuweather's site browsing their videos though... :)
Member Since: November 24, 2005 Posts: 635 Comments: 26700
Quoting GeoffreyWPB:
The late Lee Strasberg as Hyman Roth was phenomenal in the sequel.


I never trusted Hyman Roth.
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The late Lee Strasberg as Hyman Roth was phenomenal in the sequel.
Member Since: September 10, 2007 Posts: 0 Comments: 11538
Quoting Patrap:
.."You Broke my Heart Fredo"..

I've never known anyone using accuweather to be so subdued.

Is this guy a Blogger here?



Dallas - Ft. Worth, TX - Be advised for



Hahaha that guy has to be on something.
Member Since: Juli 29, 2006 Posts: 28 Comments: 1802

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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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