Dr. Jeff Masters' WunderBlog

Dakotas blizzard adds to extreme spring flooding risk

Posted by: Dr. Jeff Masters, 2:13 AM GMT op 21 februari 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.

Categories: Flood Winter Weather

Permalink | A A A

Top of Page

Reader Comments

Display: 0, 50, 100, 200

Sort: Newest First - Order Posted

Viewing: 301 - 351

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 — Blog Index

301. surfmom 2:06 AM GMT op 22 februari 2011
Quoting aquak9: post 260 aussie, it says only folks in australia can see it and I apologize for the self-centeredness of many americans, we're not all like that, I promise your home has been in a lotta my prayers, just wanted you to know (hangs head in shame) Me Too!!! Member Since: 18 juli 2007 Posts: 30 Comments: 26538

302. PcolaDan 2:07 AM GMT op 22 februari 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: 22 augustus 2008 Posts: 12 Comments: 6008

303. presslord 2:09 AM GMT op 22 februari 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: 13 augustus 2007 Posts: 0 Comments: 10377

305. AussieStorm 2:10 AM GMT op 22 februari 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 do Wouldn't be surprised if there was amputees like Haiti Member Since: 30 september 2007 Posts: 5 Comments: 13351

306. aquak9 2:13 AM GMT op 22 februari 2011
love to you, surf I 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: 13 augustus 2005 Posts: 163 Comments: 25008

307. AussieStorm 2:15 AM GMT op 22 februari 2011
Quoting aquak9: love to you, surf I 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 Quake struck at 12:51pm Member Since: 30 september 2007 Posts: 5 Comments: 13351

308. Levi32 2:16 AM GMT op 22 februari 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: 24 november 2005 Posts: 586 Comments: 25456

310. cchsweatherman 2:18 AM GMT op 22 februari 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! I'll be ready to help get involved once again down here in South Florida if needed. Member Since: 14 april 2007 Posts: 8 Comments: 4926

311. PcolaDan 2:18 AM GMT op 22 februari 2011
Quoting aquak9: love to you, surf I 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 Aftershocks seem to be getting deeper. MAP 5.5 2011/02/22 01:50:29 -43.588 172.734 9.6 SOUTH ISLAND OF NEW ZEALAND MAP 5.6 2011/02/22 00:04:18 -43.580 172.798 6.7 SOUTH ISLAND OF NEW ZEALAND MAP 6.3 2011/02/21 23:51:43 -43.600 172.710 5.0 SOUTH ISLAND OF NEW ZEALAND Member Since: 22 augustus 2008 Posts: 12 Comments: 6008

312. presslord 2:19 AM GMT op 22 februari 2011
Quoting AussieStorm: Will do Wouldn't be surprised if there was amputees like Haiti good point Member Since: 13 augustus 2007 Posts: 0 Comments: 10377

313. PcolaDan 2:20 AM GMT op 22 februari 2011
Quoting twincomanche: You people are so tiresome. Get over yourselves. So, no answer? And a repeat of a statement I made for you. Original. Member Since: 22 augustus 2008 Posts: 12 Comments: 6008

315. presslord 2:20 AM GMT op 22 februari 2011
Quoting cchsweatherman: I'll be ready to help get involved once again down here in South Florida if needed. Great! Thanks!! let's see how it all unfolds... Member Since: 13 augustus 2007 Posts: 0 Comments: 10377

317. hcubed 2:21 AM GMT op 22 februari 2011
Quoting Patrap: #211. Fascinating. Wrong,,but still fascinating. 800,000 Year Record of Carbon Dioxide (CO2) Concentrations And, according to the latest number of 391.19ppm, we're still inside that blue dot. Member Since: 18 mei 2007 Posts: 286 Comments: 1639

318. AussieStorm 2:22 AM GMT op 22 februari 2011
This link is now working. Link Member Since: 30 september 2007 Posts: 5 Comments: 13351

319. miamiheat 2:22 AM GMT op 22 februari 2011
our hearts to those struggling with the quate!! Member Since: 10 maart 2010 Posts: 0 Comments: 30

320. PcolaDan 2:22 AM GMT op 22 februari 2011
2.55pm – There are reports 60 percent of Lyttelton has been virtually demolished. Live updates. Member Since: 22 augustus 2008 Posts: 12 Comments: 6008

321. AussieStorm 2:22 AM GMT op 22 februari 2011
Quoting JohnTucker: SC sending help to Chch Timaru Hospital and Bidwill Hospital are preparing to help Christchurch with casualties following today's earthquake as another powerful aftershock hit the region. Timaru emergency services are unaware of any damage in South Canterbury and are preparing to send staff north to assist. At Timaru Hospital, an incident operations centre has been set up. SC is South Canterbury. There are a few hospitals in CC. Im not sure which one had to be evacuated. ChristChurch Hospital has been evacuated Member Since: 30 september 2007 Posts: 5 Comments: 13351

322. aquak9 2:23 AM GMT op 22 februari 2011
Pcola...I know zilch about geological tectonics in that area...but Damn that's a crack, an angry living crack... prayers for those scared people in NZ, I understand that fear Member Since: 13 augustus 2005 Posts: 163 Comments: 25008

324. miamiheat 2:24 AM GMT op 22 februari 2011
hi ,preslord ,dont forget ask for help to your good friend with FEMA , Member Since: 10 maart 2010 Posts: 0 Comments: 30

325. caneswatch 2:27 AM GMT op 22 februari 2011
Quoting PcolaDan: Aftershocks seem to be getting deeper. MAP 5.5 2011/02/22 01:50:29 -43.588 172.734 9.6 SOUTH ISLAND OF NEW ZEALAND MAP 5.6 2011/02/22 00:04:18 -43.580 172.798 6.7 SOUTH ISLAND OF NEW ZEALAND MAP 6.3 2011/02/21 23:51:43 -43.600 172.710 5.0 SOUTH ISLAND OF NEW ZEALAND 9.6? That's not good........ Member Since: 8 oktober 2008 Posts: 14 Comments: 4473

328. aquak9 2:29 AM GMT op 22 februari 2011
caneswatch those are the DEPTHS he's got highlighted, not the mag mag is the number after MAP and Luzon phillipines adds thier own 5.3, but it's really deep dear God hear us Member Since: 13 augustus 2005 Posts: 163 Comments: 25008

330. PcolaDan 2:31 AM GMT op 22 februari 2011
Quoting twincomanche: A new person making their first post if it makes sense is as valuable as a old timer making their one thousandth post. Don't be so damn arrogant that you think that since you have been here since grass started to grow that your opinion is any more valuable than anyone else. Never did I say otherwise. Happens all the time I will say it more slowly since you missed it the first two times. R E S P E C T Aussie has earned it. "long respected blogger", is what I said. Don't be so myopic in your reading and understanding. Member Since: 22 augustus 2008 Posts: 12 Comments: 6008

331. AussieStorm 2:32 AM GMT op 22 februari 2011
I am about to turn off my Stream. ABC News 24 has the same stream here, Better quality sound and video. Member Since: 30 september 2007 Posts: 5 Comments: 13351

332. Some1Has2BtheRookie 2:32 AM GMT op 22 februari 2011
Quoting AussieStorm: Try this stream Link This link works, Aussie, but there is a lot of latency, even on low quality settings. At least we can get something. Thanks! Best to you and to all there. Member Since: 24 augustus 2010 Posts: 0 Comments: 4102

333. PcolaDan 2:33 AM GMT op 22 februari 2011
"Images are coming in of what is believed to be the Pyne Gould Guinness building in Christchurch, which has been completely destroyed. People at the scene are saying about 200 people are trapped inside and screams can be heard from within the building. Kristy Clemence has just been rescued from the top of the building by the fire service. “There are a lot of people in there,” says one woman currently working with emergency services. Two woman interviewed by 3 News had just left the building when the quake struck. Ambulances have run out so police are now taking people to safety in their police cars." Member Since: 22 augustus 2008 Posts: 12 Comments: 6008

335. cchsweatherman 2:34 AM GMT op 22 februari 2011
Member Since: 14 april 2007 Posts: 8 Comments: 4926

336. PcolaDan 2:35 AM GMT op 22 februari 2011
Quoting AussieStorm: I am about to turn off my Stream. ABC News 24 has the same stream here, Better quality sound and video. Thanks Aussie. That one works here in US. Member Since: 22 augustus 2008 Posts: 12 Comments: 6008

337. PcolaDan 2:38 AM GMT op 22 februari 2011
Quoting twincomanche: Beam me up Scottie. There's no intelligent life down here. I'm gone for the night. The giant ego reigns. And still no answer as to who you were before, or if you were banned. Just another blissful retort. Member Since: 22 augustus 2008 Posts: 12 Comments: 6008

338. AussieStorm 2:39 AM GMT op 22 februari 2011
Quoting PcolaDan: Never did I say otherwise. Happens all the time I will say it more slowly since you missed it the first two times. R E S P E C T Aussie has earned it. "long respected blogger", is what I said. Don't be so myopic in your reading and understanding. Oh, I didn't realise that was directed at me, Was to busy trying to give everyone here info on the Christchurch Quake. Whatever floats his boat and boosts his ego. Member Since: 30 september 2007 Posts: 5 Comments: 13351

341. AussieStorm 2:40 AM GMT op 22 februari 2011
Quoting twincomanche: Beam me up Scottie. There's no intelligent life down here. I'm gone for the night. The giant ego reigns. Oh i think you have the giant ego... goodbye Member Since: 30 september 2007 Posts: 5 Comments: 13351

342. AussieStorm 2:44 AM GMT op 22 februari 2011
Member Since: 30 september 2007 Posts: 5 Comments: 13351

344. PcolaDan 2:44 AM GMT op 22 februari 2011
Quoting AussieStorm: Oh, I didn't realise that was directed at me, Was to busy trying to give everyone here info on the Christchurch Quake. Whatever floats his boat and boosts his ego. And I think you know a whole lot of us appreciate the effort. Member Since: 22 augustus 2008 Posts: 12 Comments: 6008

345. AussieStorm 2:51 AM GMT op 22 februari 2011
Quoting PcolaDan: And I think you know a whole lot of us appreciate the effort. Image from inside the Christchurch Cathedral Member Since: 30 september 2007 Posts: 5 Comments: 13351

347. presslord 2:53 AM GMT op 22 februari 2011
Quoting AussieStorm: Image from inside the Christchurch Cathedral Is that Catholic or Anglican? Member Since: 13 augustus 2007 Posts: 0 Comments: 10377

348. Patrap 2:57 AM GMT op 22 februari 2011
Its a time of great stress and deeds of Human compassion and when uncommon valor becomes a common virtue. Lives are in the balance and adrenalin is doing now what cant wait for machinery in some cases. My thoughts go out to the affected in NZ and those folks are going to need a lotta help real fast like. Austrailia will be the lead as they are close and Reliefweb reports ar claxoning in my inbox now. Member Since: 3 juli 2005 Posts: 371 Comments: 111546

349. AussieStorm 2:58 AM GMT op 22 februari 2011
Quoting presslord: Is that Catholic or Anglican? Anglican Member Since: 30 september 2007 Posts: 5 Comments: 13351

350. PcolaDan 2:59 AM GMT op 22 februari 2011
Quoting presslord: Is that Catholic or Anglican? Anglican Member Since: 22 augustus 2008 Posts: 12 Comments: 6008

351. aquak9 2:59 AM GMT op 22 februari 2011
(sniff) Member Since: 13 augustus 2005 Posts: 163 Comments: 25008

Viewing: 301 - 351

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 — Blog Index

Top of Page

New Comment

Community Standards Policy 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.

About JeffMasters