Unprecented floods on the Mississippi, in Colombia, and Canada

By: Dr. Jeff Masters , 14:58 GMT le 16 mai 2011

Share this Blog
6
+

The great Mississippi River flood of 2011 continues to make history, with Saturday's opening of the flood gates of the Morganza Spillway marking just the second time that flood control structure has been used since its construction in 1956. With the Morganza, Bonnet Carre', and Birds Point-New Madrid Spillways all open, the Army Corps of Engineers has now opened all of its major spillways simultaneously for the first time ever. The Mississippi is rising at Vicksburg, Mississippi, where the water has now reached 56.5', exceeding the previous all-time record of 56.2', set during the great flood of 1927. Natchez, Mississippi, is also at its greatest flood height on record, with the water at 60.6'. The previous record high was 58', set in 1937. However, the opening of the Morganza spillway has reduced the predicted heights of the great flood of 2011 from Natchez to New Orleans by 1 to 1.5'. This will serve to greatly reduce the pressure on the levees and on the Old River Control Structure, which as I discussed in my previous post, is America's Achilles' heel, and must be protected. According the National Weather Service, flood heights along the Lower Mississippi from Natchez to New Orleans will peak this week, and slowly fall next week. Rainfall over the next five days is expected to be minimal over the Lower Mississippi watershed. The next chance for significant rain over the region will come Sunday, May 22.


Figure 1. Saturday's opening of the first gate on the Morganza Spillway, as seen on the live feed from USTREAM.

Devastating flooding continues in Colombia
Devastating flooding has hit South America in Colombia, where exceptionally heavy spring rains have killed at least 425 people so far this year, with 482 others missing. Damages are in the billions, and there are 3 million disaster victims. "Some parts of the country have been set back 15 to 20 years", said Plan’s Country Director in Colombia, Gabriela Bucher. "Over the past 10 months we have registered five or six times more rainfall than usual," said the director of Colombia's weather service, Ricardo Lozano. Up to 800 mm (about 32 inches) of rain has fallen along the Pacific coast of Colombia over the past two weeks (Figure 3). The severe spring flooding follows on the heels of the heaviest fall rains in Colombia's History. Weather records go back 42 year in Colombia. Colombia's president Juan Manuel Santos said, "the tragedy the country is going through has no precedents in our history." The 2010 floods killed 571 people--the second deadliest year for floods in Colombian history, next to 1987. The floods did over $1 billion in damage, and affected 2.8 million people. In many places, the flood waters from this great disaster never fully receded, and are now rising again due to this latest round of intense flooding. More rain is in the forecast--the latest forecast from the GFS model calls for an additional 5 - 10 inches (200 - 400 mm) across much of western and northern Colombia in the coming week.


Figure 2. Satellite-observed rainfall over Colombia during the past two weeks shows a region of up to 800 mm (about 32 inches) has fallen near the Pacific coast. Image credit: Navy Research Lab, Monterey.

Colombia's rainy season usually has two peaks: one the fall in October, then then another in the spring in April - May. The heavy rains are due to the presence of the Intertropical Convergence Zone, the area encircling the earth near the Equator where winds originating in the northern and southern hemispheres come together. When these great wind belts come together (or "converge", thus the name "Convergence Zone"), the converging air is forced upwards, since it has nowhere else to go. The rising air fuels strong thunderstorm updrafts, creating a band of very heavy storms capable of causing heavy flooding rains. In La Niña years, when a large region of colder than average water is off the Pacific coast of Colombia, rainfall tends to increase over Colombia. La Niña was moderate to strong during the fall 2010 rains and floods in Colombia, and was largely to blame for Colombia's deadly rainy season. However, in recent months, La Niña has waned. April sea surface temperatures off the Pacific coast of Colombia (0° - 10°N, 85° - 75°W), warmed to the 13th highest temperatures in the past 100 years, 0.68°C above average. Thus, this month's flooding in Colombia may not be due to La Niña.

See also my December 2010 post, Heaviest rains in Colombia's history trigger deadly landslide; 145 dead or missing


Figure 3. Dramatic video of flooding in Colombia over the weekend. Flood waters swept away cars and buses in a busy street in the city of Barranquilla, and passengers climbed on the roofs of their vehicles in order to escape the flood waters. Video credit: BBC.

300-year flood in Canada; wildfires destroy large portions of Slave Lake, Alberta
In Manitoba, Canada, heavy spring snow melt in combination with heavy rains have combined to create record flooding on the Assiniboine River. Authorities intentionally breached a levee over the weekend to save hundreds of homes, but inundated huge areas of farmland as a result. The flood is being called a 300-year flood, and damages are already in excess of $1 billion. In Alberta, Canada, reverse extreme is causing havoc: severe drought and strong spring winds have made ideal conditions for wildfires, which swept into the community of Slave Lake (population 6,700) yesterday. The fires destroyed hundreds of buildings, burning down the town hall and at least 30% of the town, according to preliminary media reports.


Figure 4. Video of the May 15, 2011 Slave Lake fire.

First tropical wave of the year over the Atlantic
The first tropical wave of 2011 is now over the tropical Atlantic near 6°N 46°W, according to the latest Atlantic Tropical Weather Discussion. The wave will bring heavy rain to the northeast coast of South America over the next two days, but is too far south to be a threat to develop into a tropical depression. The Atlantic hurricane season is just two weeks away, and the Eastern Pacific hurricane season began yesterday. So far, the models are not predicting any tropical storm development in the East Pacific or Atlantic over the next six days.

Jeff Masters

The Great Flood of 2011 (jperilloux)
KCS train crossing the trestle through the Bonnet Carre Spillway at Norco, LA. Flood water diverted from Miss. River
The Great Flood of 2011

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 156 - 106

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10Blog Index

Quoting TropicalAnalystwx13:
ahhh....the old Taz reporting posts, JFV, the chart....reminds of last season....good times XD.


And the season before last, and the season before that one, and so on and so forth...
Member Since: Posts: Comments:
We should probably get back on topic now though...
Member Since: Posts: Comments:
ahhh....the old Taz reporting posts, JFV, the chart....reminds of last season....good times XD.
Member Since: Posts: Comments:
oh wants too see me in a drss
Member Since: 21 mai 2006 Posts: 5091 Comments: 115454
Quoting aquak9:
That is one ugly shower curtain.

you oughtta see what crawls outta the shower...


lmao...+100000000000
Member Since: Posts: Comments:
Quoting MississippiWx:


Ahhh, such a beautiful curtain. I might get one.




ahhhhhhhhhhhhhhhhhhhhhhhhhh



LOL
Member Since: 21 mai 2006 Posts: 5091 Comments: 115454
That is one ugly shower curtain.

you oughtta see what crawls outta the shower...
Member Since: 13 août 2005 Posts: 178 Comments: 26648
Quoting Levi32:
It's quite obvious where all the upward motion from the MJO is right now. It's all over the eastern Pacific and western Atlantic. The only problem is that it is all too far south. Once it lifts north, which will likely be before the end of the month, it will be able to stir up possible trouble. Until then, it is bottled up safely.



The upper low drifting around the SE US is really helping to suppress any thunderstorm activity in the Gulf and Western Caribbean. Tons of dry air...
Member Since: Posts: Comments:
mmm...
I'm thinking a black leather curtain...
Member Since: 13 août 2005 Posts: 178 Comments: 26648
Doc Masters didn't mention the 7 day gfs because he didn't want to start a frenzy...."I see some spin"...."it's heading to Florida"..."it's a fish storm"....blah blah blah.;^)
Member Since: Posts: Comments:
Quoting RingOfDestruction:


If only, remember that it's very difficult for him to comprehend that, cause he ain't like the rest of us, -__-.


Lol....

Should I say it or should everyone figure it out on their own?
Member Since: Posts: Comments:
Gulf and Carribbean has been swept clean with dry air
Member Since: Posts: Comments:
Member Since: Posts: Comments:
It's quite obvious where all the upward motion from the MJO is right now. It's all over the eastern Pacific and western Atlantic. The only problem is that it is all too far south. Once it lifts north, which will likely be before the end of the month, it will be able to stir up possible trouble. Until then, it is bottled up safely.



Member Since: Posts: Comments:
An extensive amount of moisture with the Atlantic low...
Member Since: 27 septembre 2007 Posts: 1 Comments: 22640
Quoting DestinJeff:


Taz is right. Too many The Charts get in the way of The Curtain:




Ahhh, such a beautiful curtain. I might get one.
Member Since: Posts: Comments:
Quoting RitaEvac:
Stop interupting the blog please...

JFV=


Now you've really done it...
Member Since: Posts: Comments:
Quoting DestinJeff:


yeah. My work here is done.

Not fair to say I stir up trouble, that's all Dewey and his alternate universe blog of yesteryear.

Where is he anyway?


LOL...I stand corrected. You are correct about him stirring the pot. And who knows? Maybe he stirred up trouble with the wrong person?
Member Since: Posts: Comments:
weak Saharan air layer at the momentLink
Member Since: Posts: Comments:
LOL...am I the only one with audio?
Member Since: Posts: Comments:
Plenty of convection in the Pacific off the Central American coast...
Member Since: 27 septembre 2007 Posts: 1 Comments: 22640
lol, yea who posts that?
Member Since: Posts: Comments:
ya'll are ALL a bunch of slackers from what I can see!! Now get to work!

(YAY!! TheChart!!)
Member Since: 13 août 2005 Posts: 178 Comments: 26648
Quoting RitaEvac:
Supposed to have an arrow where were at saying "You are Here"


RitaEvac...we need that moutain climber guy from The Price is Right..with the "yodel" song playing in the background....lol
Member Since: Posts: Comments:
Member Since: 27 septembre 2007 Posts: 1 Comments: 22640
StormTop has entered the blog somewhere
Member Since: Posts: Comments:
roflmao...now the blogging season has really begun! Shields UP Taz!
Member Since: Posts: Comments:
Supposed to have an arrow where were at saying "You are Here"

Member Since: Posts: Comments:
Quoting RingOfDestruction:
Dr. Masters, by when will you be putting forth your forecast for the upcoming 2011 Atlantic Hurricane Season, sir? I'm already beginning to look forward to it, professor, ^_^.




JFV you been reported for bypassing the Admin banneds
Member Since: 21 mai 2006 Posts: 5091 Comments: 115454
Quoting DestinJeff:


Thanks, Dr. Masters. Just giving you a good-natured ribbing. Obviously I pay attention to and appreciate your posts, but some of us here do mine humor from wherever we can.

Well, some call it humor anyway.


Always stirring up trouble...now stirring it up with the Doc himself!
Member Since: Posts: Comments:
Quoting RingOfDestruction:
Dr. Masters, by when will you be putting forth your forecast for the upcoming 2011 Atlantic Hurricane Season, sir? I'm already beginning to look forward to it, professor, ^_^.





when will you evere get it
Member Since: 21 mai 2006 Posts: 5091 Comments: 115454
Quoting DestinJeff:


Thanks, Dr. Masters. Just giving you a good-natured ribbing. Obviously I pay attention to and appreciate your posts, but some of us here do mine humor from wherever we can.

Well, some call it humor anyway.
I thrive on humor.......Simon says its prayer time.......!..Gospel chart shrine...:)
Member Since: 27 septembre 2007 Posts: 1 Comments: 22640
Quoting USAprimeCreditPeggy:
I am still waiting for "The Chart".


Eh hem...DestinJeff....
Member Since: Posts: Comments:
SST's are looking good ( for trop. storms, anyway) in the south east Carib they are already up to 83f, and off southern Mexico in the Pacific, they are at 86f.
Plenty potential energy around already.

Oh, and right now it's raining hard for the last 15 mins or so.
Very nice!
Member Since: 24 octobre 2005 Posts: 0 Comments: 24883
Maybe I ought to leave a message in a bottle on the beach that says "RitaEvac was just here, see ya in cyberspace on the blog next week!" lol
Member Since: Posts: Comments:
Quoting MississippiWx:


Really heated up in the past week or so.


Rocket Fuel?? LOL.

I hope I am the first with that line this year.
Member Since: Posts: Comments:
Quoting RastaSteve:


We will just miss each other. I leave on 6/5 and comeback 6/12. I think I'm in Cozumel on 6/10.


That would be scarey to run into each other
Member Since: Posts: Comments:
Quoting MississippiWx:


Really heated up in the past week or so.
yes it is
Member Since: Posts: Comments:
Member Since: Posts: Comments:

Viewing: 156 - 106

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10Blog Index

Top of Page

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.

Local Weather

Clear
24 ° F
Ciel dégagé

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron