# Dakotas blizzard adds to extreme spring flooding risk

By: Dr. Jeff Masters , 2:13 AM GMT on February 21, 2011

Heavy snows in excess of six inches have piled up over much of South Dakota, North Dakota, Montana, Wisconsin, and Minnesota today, with a storm maximum of 16 inches reported at Midland, South Dakota. This is bad news for residents in flood-prone areas of the Upper Midwest, as the new storm has added more than another half inch of melted rainfall equivalent to a snowpack that already had a record water content. When all that snow melts in late March, we can expect another spring of major and possibly record flooding for North Dakota, South Dakota, Minnesota, or the Upper Mississippi River north of St. Louis, according to the National Weather Service (NWS). Their February Spring Flood Outlook released last week warned: "Heavy autumn rains and above average water content in the snow pack throughout the North Central U.S. have produced a high risk of moderate and major flooding for the Spring of 2011. Areas of greatest concern include the Red River of the North in North Dakota and Minnesota, Devils Lake in North Dakota, the James River and Big Sioux River in South Dakota, and areas along the Upper Mississippi River including Minnesota, Wisconsin, Iowa, Illinois and Missouri.

Heavy late summer and autumn precipitation (twice the normal amount since October in parts of North Dakota and Minnesota) have soils saturated and streams running high before the winter freeze-up. Another winter of above average snowfall has added water to the snow pack on top of the frozen saturated soils in the North Central US. NWS models show this snowpack containing a water content ranked in the 90 to 100 percentile when compared to a 60 year average. These factors have combined to create some of the highest soil moisture contents of the last century. "

Figure 1. North Central U.S. flood risk. Image credit: NWS. The outlook will be updated on February 24, and a final outlook issued March 17.

There is a huge amount of snow on the ground in North Dakota along the tributaries of the Red River, thanks to fall precipitation that was 150% - 300% of normal, and winter snows that have dumped up to 400% more precipitation than usual. If one were to melt this snow, it would amount to 4 - 5 inches of rain. If heavy rains occur at the same time that the snow melts, there is the potential for the greatest flood in history to affect the cities of Fargo and Grand Forks, the largest and third largest cities in North Dakota. NWS is giving a 20% chance that Fargo will see its greatest flood in history, and a 10% chance for Grand Forks.

The situation is similar in Minnesota, which has received about double its normal precipitation over the past 3 to 4 months. Snow depths are generally around 18 inches in the Upper Mississippi watershed, with a high water content. If one were to melt this snow, it would amount to 3.5 - 5.5 inches of rain, which ranks among the wettest snow packs in the 60-year record. NWS is giving a 15% chance that St. Paul will see its highest flood in history this spring.

In South Dakota, heavy snows this winter have also left a snowpack with a high water content, and NWS is predicting a 30% chance that the the James River at Huron, SD and the Big Sioux River at Brookings, SD will reach their highest flood heights in history.

Figure 2. The snow water equivalent of the Upper Midwest's snowpack as of February 18, 2011. Large sections of Minnesota and North Dakota have the equivalent of 3.9 - 5.9 inches of rain (purple colors) stored in their snowpack. Image credit: NWS/NOHRSC.

When will all this flooding occur? Generally, late March through mid-April is the time when the big spring melt occurs. The record 2009 Red River flood peaked on March 28 in Fargo. The great 1997 Red River flood that devastated Grand Forks, causing \$3.5 billion in damage, crested on April 18. St. Paul's greatest flood in history crested on April 19, 1965.

I'll have a new post Tuesday or Wednesday.

Jeff Masters

Blinding snowstorm hits Detroit area (MichiganSnowLvr)
The Detroit area was hit with a blinding snowstorm this afternoon and evening, with near zero visibility and thunder/lightning, as the snowfall piles up quickly and deeply.

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##### 308. Levi32
2:16 AM GMT on February 22, 2011
 By the way, according to Jesse Ferrell on Facebook, Joe Bastardi was not fired from Accuweather, but that's all he knows about it. In other words, it sounds like he is leaving of his own accord, or something along those lines.
Member Since: November 24, 2005 Posts: 635 Comments: 26780
##### 307. AussieStorm
2:15 AM GMT on February 22, 2011
 Quoting aquak9:love to you, surfI know this- a 6.8 mag at 15 miles deep will bounce you offa a very heavy couch. I can't imagine a 6.3 at only 4 miles deep. love surfmomQuake struck at 12:51pm
Member Since: September 30, 2007 Posts: 9 Comments: 16036
##### 306. aquak9
2:13 AM GMT on February 22, 2011
 love to you, surfI know this- a 6.8 mag at 15 miles deep will bounce you offa a very heavy couch. I can't imagine a 6.3 at only 4 miles deep. love surfmom
Member Since: August 13, 2005 Posts: 195 Comments: 28602
##### 305. AussieStorm
2:10 AM GMT on February 22, 2011
 Quoting presslord:Aussie....Would you please keep a particular lookout for needs involving people with disabilities in New Zealand? If you come across anything please shoot me a WU mail...Thanks!Will doWouldn't be surprised if there was amputees like Haiti
Member Since: September 30, 2007 Posts: 9 Comments: 16036
##### 304. JFLORIDA
2:10 AM GMT on February 22, 2011
 A well-known approximation used to calculate the dew point Td given the relative humidity RH and the actual temperature T of air is:$T_d = \frac {b\ \gamma(T,RH)} {a - \gamma(T,RH)}$ where$\gamma(T,RH) = \frac {a\ T} {b+T} + \ln (RH/100)$ where the temperatures are in degrees Celsius and "ln" refers to the natural logarithm. The constants are:a = 17.27 b = 237.7 °C This expression is based on the "Magnus" (or "Magnus-Tetens") approximation for the saturation vapor pressure of water in air as a function of temperature.[3] It is considered valid for0 °C < T < 60 °C 1% < RH < 100% 0 °C < Td < 50 °C So indeed only the ln of the RH/100 is changing. -0.1053605156578 for 90%-0.2231435513142 for 80%
Member Since: May 22, 2006 Posts: 188 Comments: 24743
##### 303. presslord
2:09 AM GMT on February 22, 2011
 Aussie....Would you please keep a particular lookout for needs involving people with disabilities in New Zealand? If you come across anything please shoot me a WU mail...Thanks!
Member Since: August 13, 2007 Posts: 0 Comments: 10538
2:07 AM GMT on February 22, 2011
 Quoting RecordSeason:273:Yes.It's very close to the surface, making it exponentially more damaging per unit energy released.GNS says acceleration was a full 1G, against 0.8G for September, which equates to a 25% higher speed of movement at ground level.
Member Since: August 22, 2008 Posts: 12 Comments: 6010
##### 301. surfmom
2:06 AM GMT on February 22, 2011
 Quoting aquak9:post 260aussie, it says only folks in australia can see itand I apologize for the self-centeredness of many americans, we're not all like that, I promiseyour home has been in a lotta my prayers, just wanted you to know (hangs head in shame)Me Too!!!
Member Since: July 18, 2007 Posts: 30 Comments: 26536
##### 300. AussieStorm
 My Ustream, streaming live news from Christchurch. Live Videos by UstreamMy wife just came home from work. I gave her a massive hug.I think all of us should do the same to our loved ones.
Member Since: September 30, 2007 Posts: 9 Comments: 16036
 Quoting twincomanche:I'm sure his opinions are much more valuable since he has been here longer. No one has to do anything I think, however I am entitled to my opinion. What we think about world events are probably better left to a blog dedicated to that IMHO. Natural events have always been posted here. I have been here longer than you know.His opinions are more valuable because he has earned RESPECT, (you must have skipped over that word on my original post). And if you have been here so long, why are you not using that user name? Was it banned?
Member Since: August 22, 2008 Posts: 12 Comments: 6010
##### 298. surfmom
 thanks Aqua
Member Since: July 18, 2007 Posts: 30 Comments: 26536
##### 297. AussieStorm
 Quoting cchsweatherman:Unfortunately, its a byproduct of freedom of speech. People are free to talk about what they want as long as it falls within the rules, whether we like it or not. I appreciate your passion into this tragedy, but some may not care as much as you.yes they care about some guy on a rival website and not about people dying
Member Since: September 30, 2007 Posts: 9 Comments: 16036
##### 296. RecordSeason
 273:Yes.It's very close to the surface, making it exponentially more damaging per unit energy released.
Member Since: June 13, 2010 Posts: 0 Comments: 2336
##### 295. weatherboy1992
 The New Zealand Herald is a good news source about the earthquake. It has been a bit jumpy--I think its web traffic is more than it is used to.
##### 294. TomTaylor
 Quoting Levi32:Forecasting is exactly what predicting global temperature is. The only problem here is getting involved in a politically polluted issue on the side that is most ridiculed. When has that ever turned out good for anybody.Maybe it's because they deny everything you throw at them. Global Warming has been proven to be happening. Humans have been proven to be warming the planet. Anyone who thinks otherwise is in a state of denial. Time to stop sympathizing with them, Levi.
##### 293. weatherboy1992
 Thank you Tom Taylor. I didn't think of all your additional factors--just a couple of big ones. In reality net radiative forcing by greenhouse gases is probably 750-1000 times that of road surfaces. It is a good point of TomTaylor's that roads are not blackbodies and depending on material may reflect 10% or even more radiation that falls on them.
##### 292. Drakoen
 Quoting Levi32:JB is a brilliant meteorologist. People like him are completely entitled to their opinions on AGW, and that should never be a reason to fire him. His long-range forecasts are forecasts that nobody else dares to make, and he's right a good portion of the time. His main focus in his job has nothing to do with AGW, but weather forecasting for the U.S. and Europe, which he has done a very fine job of. JB is only subjective in some aspects of his AGW beliefs, but as a meteorologist he is one of the best in the business. Tarnishing his name here only tarnishes yours, as many people speaking in this blog have shown tremendous inability to be objective and fair.A "brilliant meteorologist"? I beg to differ. First, it was absolutely necessary for Accuweather to fire him after his wrongful attack on NSIDC. If Accuweather had not fired him, then they would be standing by falsified accusations. Maybe Accuuweather can now gain some credibility now that he is gone. He doesn't know how to read basic maps, or know the difference between an anomaly and standardized anomaly. Farthest thing from brilliant, in any sense of the word. I terribly surprised when I saw his video comparing the temperature anomalies to the sea ice extent.You are mistaken in that he was fired for his opinion on AGW. His general lack of respect for the NHC, NWS, NSIDC and possibly and probably any other environmental agency opposed to his views is what led to his downfall.
##### 290. aquak9
 only decent new zealand seismo I could find quickstill cracking, I see a five and maybe a six hard jolt...I am so sorry aussie for your neighbors, the vid and sound on your ustream is frightening
Member Since: August 13, 2005 Posts: 195 Comments: 28602
##### 289. cchsweatherman
 Quoting AussieStorm:But people here arguing about some guy on a rival website quitting is just stupidUnfortunately, its a byproduct of freedom of speech. People are free to talk about what they want as long as it falls within the rules, whether we like it or not. I appreciate your passion into this tragedy, but some may not care as much as you.
Member Since: April 14, 2007 Posts: 8 Comments: 5169
##### 288. twincomanche
 Quoting PcolaDan:So, the new kid on the block is the one who decides what is discussed here, while the long respected blogger who keeps us informed of happenings in the southern hemisphere is to be ignored? I think not.Get over yourself.I'm sure his opinions are much more valuable since he has been here longer. No one has to do anything I think, however I am entitled to my opinion. What we think about world events are probably better left to a blog dedicated to that IMHO. Natural events have always been posted here. I have been here longer than you know.
Member Since: January 2, 2011 Posts: 0 Comments: 586
##### 287. AussieStorm
Member Since: September 30, 2007 Posts: 9 Comments: 16036
##### 286. aquak9
 papua new guinea seismobig slapping crack there
Member Since: August 13, 2005 Posts: 195 Comments: 28602
##### 285. weatherboy1992
 RecordSeason's monomania about water not absorbing infrared radiation and posting youtube videos of light and IR beams passing through small water containers is irrelevant.Yes most IR and light can pass through small containers of water, if the water is reasonably pure.But the ocean is not small and it is not pure.If RecordSeason's conclusions were valid and relevant, the oceans would be transparent. We could see from the surface to the abyssal plains at the bottom. We would have known about spreading ridges--just look and see!The ocean would be bright all the way down, and we would have kelp forests on the sea floor, photosynthesizing. Recordseason's points are just not true. Because oceans are not transparent, and sea water absorbs IR and visible light efficiently.
##### 284. AussieStorm
 Quoting cchsweatherman:Even though I share your sentiment as I have shown, we can't do anything beyond send our best wishes and report the news as we receive it at this point.But people here arguing about some guy on a rival website quitting is just stupid
Member Since: September 30, 2007 Posts: 9 Comments: 16036
##### 283. cchsweatherman
 Quoting AussieStorm:What the HELL is wrong with you people.... People are dying in Christchurch and Libya and your all arguing about a guy quitting a rival website. God help us.Even though I share your sentiment as I have shown, we can't do anything beyond send our best wishes and report the news as we receive it at this point.
Member Since: April 14, 2007 Posts: 8 Comments: 5169
##### 282. caneswatch
 Quoting twincomanche:Should we be talking about that here? I think not.About what's going on in Christchurch, yes. Earthquakes are natural, and like this one, they're deadly. Libya, no. That's for elsewhere.You should've thought twice before you said no to both events.
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Member Since: August 22, 2008 Posts: 12 Comments: 6010
##### 280. twincomanche
 Quoting AussieStorm:Should we be talking about what... Earthquakes or rivalsEarthquakes is ok but political stuff would seem to be off limits unless of course you are trashing Fox News.
Member Since: January 2, 2011 Posts: 0 Comments: 586
##### 279. JFLORIDA
 So it looks like error in the dew point calculation - is that correct? Not much but about 2 degrees for frost point. Frostpoint Tfp Corresponding to the dewpoint for freezing conditions, the frostpoint is the temperature at which ice will form on the cool body. The frostpoint for liquid water is slightly higher than the dewpoint. Because the formation of ice depends on a certain amount of impurity on the surface of the body, however, you may still experience dew at subzero temperatures.
Member Since: May 22, 2006 Posts: 188 Comments: 24743
 Quoting twincomanche:Should we be talking about that here? I think not.So, the new kid on the block is the one who decides what is discussed here, while the long respected blogger who keeps us informed of happenings in the southern hemisphere is to be ignored? I think not.Get over yourself.
Member Since: August 22, 2008 Posts: 12 Comments: 6010
##### 277. TomTaylor
 Quoting Levi32:Forecasting is exactly what predicting global temperature is. The only problem here is getting involved in a politically polluted issue on the side that is most ridiculed. When has that ever turned out good for anybody.Why do you think it's most ridiculed?According to most the people on that side, the side who "ridicules the most" are also fun loving hippie tree huggers. Yet you are right that they are the most ridiculed. hmmm, let's ponder this together.Maybe it's because they deny everything you throw at them. Global Warming has been proven to be happening. Humans have been proven to be warming the planet. Anyone who thinks otherwise is in a state of denial. Time to stop sympathizing with them, Levi.
##### 276. aquak9
 post 260aussie, it says only folks in australia can see itand I apologize for the self-centeredness of many americans, we're not all like that, I promiseyour home has been in a lotta my prayers, just wanted you to know (hangs head in shame)
Member Since: August 13, 2005 Posts: 195 Comments: 28602
##### 274. AussieStorm
Member Since: September 30, 2007 Posts: 9 Comments: 16036
##### 273. cchsweatherman
 Quoting AussieStorm:Image of Christchurch QuakeThats an impressive seismic signature right there. Can tell without the reported depth that this occurred at a very shallow depth which makes the earthquake exponentially worse.
Member Since: April 14, 2007 Posts: 8 Comments: 5169
##### 272. AussieStorm
 Quoting twincomanche:Should we be talking about that here? I think not.Should we be talking about what... Earthquakes or rivals
Member Since: September 30, 2007 Posts: 9 Comments: 16036
 Quoting AussieStorm:Watch Live News from new Zealand here.... LinkOnly available in Australia Aussie. Thanks anyway.
Member Since: August 22, 2008 Posts: 12 Comments: 6010
##### 270. twincomanche
 Quoting AussieStorm:What the HELL is wrong with you people.... People are dying in Christchurch and Libya and your all arguing about a guy quitting a rival website. God help us.Should we be talking about that here? I think not.
Member Since: January 2, 2011 Posts: 0 Comments: 586
 Quoting AussieStorm:What the HELL is wrong with you people.... People are dying in Christchurch and Libya and your all arguing about a guy quitting a rival website. God help us.Just posted link to your Ustream on the volcano blog I visit. Yea, some peoples priorities!
Member Since: August 22, 2008 Posts: 12 Comments: 6010
##### 268. AussieStorm
 Image of Christchurch Quake
Member Since: September 30, 2007 Posts: 9 Comments: 16036
##### 267. twincomanche
 Quoting caneswatch:Nice sarcasm LOL. Everything has to be studied outside of the consensus no matter what. If it wasn't there, the "consensus" would be wrong sometimes and we would be believing lies.Not to be the guy in charge of the language tonight but giving facts that may be untrue are different from lies.A lie (also called prevarication, falsehood) is a known untruth expressed as truth."A lie is a type of deception in the form of an untruthful statement, especially with the intention to deceive others, often with the further intention to maintain a secret or reputation, protect someone's feelings or to avoid a punishment or repercussion for one's actions. To lie is to state something that one knows to be false or that one does not honestly believe to be true with the intention that a person will take it for the truth. A liar is a person who is lying, who has previously lied, or who tends by nature to lie repeatedly - even when not necessary."Giving of false information thinking it to be true is just being mistaken.
Member Since: January 2, 2011 Posts: 0 Comments: 586
##### 266. caneswatch
 Quoting Levi32:Forecasting is exactly what predicting global temperature is. The only problem here is getting involved in a politically polluted issue on the side that is most ridiculed. When has that ever turned out good for anybody.Never, and i'm afraid it will remain political for a long time.
Member Since: October 8, 2008 Posts: 14 Comments: 4553
##### 265. alfabob
 Here is the proof of global climate change (can't provide the links as it was compiled from 25+ research papers, multiple databases, and is formatted into multiple excel sheets), an estimate for net energy in-flux is of the order of 6.9*10^13 watts when considering the majority of aspects (complete ocean temperature changes, global ice sheets and glaciers). Some factors such as atmospheric temperatures were not included so this is a conservative estimate. This is the amount of energy which is continuously being added to the Earth, which means that it is impossible for global warming not to be occurring.Whats even more interesting is that the suns radiance spectrum is generally between .2um - 4um, which does not include a lot of the absorption bands of CO2 and H2O. The spectrum of energy radiating from Earth is approximately 4um - 80um which does include these additional energy levels. Even more so is that adding up the contributions of heat not directly originating from the sun is very close to the previous estimate from my research:Geothermal: 47*10^12 wattsTides: 3*10^12 wattsWaste Energy (Human Induced): 13*10^12 wattsGrand Total: ~6.3*10^13 watts.It would seem to me from these initial results that the majority of additional heat is due to surface heat becoming trapped rather than inbound solar radiation (far/mid-infrared compared to near-infrared). If so, the amount of heat induced by AWG would become drastically large in comparison to the suns output (about 20% of the total). This doesn't even take into account the effect of trapping the additional heat due to the increased greenhouse gases.
##### 264. AussieStorm
 What the HELL is wrong with you people.... People are dying in Christchurch and Libya and your all arguing about a guy quitting a rival website. God help us.
Member Since: September 30, 2007 Posts: 9 Comments: 16036
##### 263. Levi32
 Quoting caneswatch:I agree. Those who are experts have shown themselves to be what they are. JB was a good expert at forecasting, yes, but that's the subject he should have stayed on.Forecasting is exactly what predicting global temperature is. The only problem here is getting involved in a politically polluted issue on the side that is most ridiculed. When has that ever turned out good for anybody.
Member Since: November 24, 2005 Posts: 635 Comments: 26780
##### 262. weatherboy1992
 If Bastardi is really gone it is about time. He's a dishonest smear merchant. He is not a great forecaster either.And RecordSeason the amount of energy released through the consumption of fossil fuels is irrelevant in the global warming debate. According to the Carbon Dioxide Information Analysis Center run by the US Department of Energy current greenhouse gas forcing is 2.9901 watts/meter squared. There are a million square meters in a square kilometer. The surface of the earth is 510,072,000 square kilometers. That yields a forcing of 1.525 petawatts. (1.525 quadrillion watts)That is 71 times RecordSeason's estimate for net additional absorption from roadways. And recordseason's estimate for net additional absorption by roadways is greatly exaggerated because he ignores important factors.
##### 261. JFLORIDA
 256. Oh that is Ohio - Fahrenheit. OKThat doesnt help.
Member Since: May 22, 2006 Posts: 188 Comments: 24743
##### 260. AussieStorm
 Watch Live News from new Zealand here.... Link
Member Since: September 30, 2007 Posts: 9 Comments: 16036
##### 259. caneswatch
 Quoting Levi32:Oh. So we're not allowed to study or consider the research of anything outside of the "consensus?" I didn't know that. I guess the consensus must always be right. I'll be sure to consult them and only them from now on.Nice sarcasm LOL. Everything has to be studied outside of the consensus no matter what. If it wasn't there, the "consensus" would be wrong sometimes and we would be believing lies.
Member Since: October 8, 2008 Posts: 14 Comments: 4553
##### 258. JFLORIDA
 Quoting caneswatch:I agree. Those who are experts have shown themselves to be what they are. JB was a good expert at forecasting, yes, but that's the subject he should have stayed on.Or you were agreeing. lol.
Member Since: May 22, 2006 Posts: 188 Comments: 24743

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### Dr. Jeff Masters' WunderBlog

Dr. Masters (r) co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

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