Flood Clues

Just three years ago, the thought that western North Dakota would be experiencing historic floods in the near future would have been seen as unrealistic considering how dry that area was as seen with the Palmer Indexes in June 2008.

Back in the summers from 2005 through 2008, moisture was in short supply, the rivers were barely running, Lake Sakakawea in 2005 was running at historic lows and rain was desperately needed.  Much of this past decade the western one-third of North Dakota experienced frequent dry spells, whereas, the eastern part of North Dakota and western Minnesota was generally experiencing very moist conditions.

By the summer of 2009, enough rain had fallen in western North Dakota that the drought was over and the transition to over saturation was starting to become more evident in some parts of central North Dakota.  This excessive moisture was from a combination of winter snow and abundant rainfall that occurred during the spring of 2009.

Unknown at that time, but the Minot flood had its roots in 2009.  But the main branches of the flood came in 2010 when the word drought seemed like a distant memory as the rains came turning the semi-arid high plains into a vast wetland.  The rivers went from dry to flowing fast, the low areas were once again filled with water and the dry days were a memory.  Instead, seeping basements, sump pumps running frequently became the norm in areas that were missed by the wetness that plagued eastern North Dakota and western Minnesota since the early 1990s.

The wet summer of 2010 was followed by a wet autumn, that was followed by a snowy winter.  Then another season of saturation occurred in the spring of 2011.  The spring of 2011 was the 7th consecutive season with above average precipitation for the state of North Dakota.  In eastern Montana it was the wettest spring on record.

The extremely wet winter in combination with one of the wettest springs since 1893 lead to a massive surge of moisture down the Missouri River.  The Missouri River flooding,  although certainly made worse by spring rains,  was mostly caused by the tremendous snow that fell during the winter of 2010-2011.  The abundant moisture in recent years has cause Lake Sakakawea to rise 49 feet since 2005.  That 49 foot rise would be enough water to cover the state of North Dakota to a depth of 4″.  That is just one small example as to how much water this area has received in recent years.

The excessive snow from the winter was not only an Rocky Mountain event, but it was also very snowy over much of the northern Great Plains.  I’m sure few of us have forgotten that Fargo Moorhead recorded the 3rd snowiest winter on record.   The prairie provinces of Canada also observed abundant snow fall this pass winter, that was followed with continuous spring rains.  Some parts of Saskatchewan likely had their wettest first six months of a year since at least 1900.

Below is a graphic for the precipitation anomalies from average (rain and melted snow) that has fallen over the northern part of the United States.  That area in eastern Montana with nearly 20″ of rain above normal does extend,  from reports,  into Saskatchewan, the source region of the Souris River that flows through Minot.  That part of the United States and Canada only averages between 12″ and 18″ of rain per year and many areas received that much in just the past two months.

Therefore, it should surprised no one that the entire northern tier of the high plains of the United States was completely saturated by the end of May 2011.  Although this Palmer Index chart below is only for the United States, the prairie provinces of Canada would be listed as extremely moist as well.

The excessive moisture found its way into all the river systems.  In Minot,  the Souris has been flowing high since early April, with the river at or above flood stage for most of the last three months.

Although the Souris was running very high, it was manageable for the city of Minot until mid June.  In fact, after a mandatory evacuation of parts of the city, the residents were allowed back in and many thought the flood fight of 2011 was over, yet, only days later, parts of the city were evacuated again and then the battle was quickly lost as the river surged to record levels.

What changed?  More rain.  With all the up stream reservoirs near or at capacity, a major rain event hit Saskatchewan with another 4-7″ of rain.  Doppler estimates of that event can be seen below:

Because of the distance from the dopplers in the United States, the estimates above do not fully describe the areal extent of the heavy rain in Canada.  This was the last straw that finally broke the proverbial “camel’s back”.  With so much water flowing into the reservoirs that were already at capacity, the dam operators had no choice but to have outputs equal inputs.  This cause the flows into the Souris River to increase from around 11,000 cubic feet per second to near 30,000 cubic feet per second rushing toward the city of Minot.   This in turn raised the Souris to record breaking levels flooding hundreds of homes and businesses.

Some floods happen in a day, but wide scaled flooding as what occurred along a huge stretch of the Missouri, the Souris and other river systems, usually have their roots in a long slow process.  Hints to the devastation in Minot came nearly two years ago with the rapid saturation of the soils and the corresponding high river flows for the past two years.

The Red River Valley has been wet for two decades now, our hints are already evident.  A major precipitation event could bring devastation to any part of the Red River drainage system.  We have seen this in the Devils Lake Basin and in Grand Forks in 1997.  Will we see it somewhere else?  Hopefully not, but if it does happen, we sadly shouldn’t be surprised.

 

17 thoughts on “Flood Clues

  1. I wrote it. It is hard to edit in Word Press before publication, but I made a couple of small edits since. What exactly are you questioning? It’s just a blog, not a formal paper. I always welcome suggestions, but please be civil.

  2. I WILL NOT BE CIVIL!!!! Good article. I’ve always been curious about the cause of all the flooding.

  3. Wow these maps are impressive. It just goes to show us that Global weather change is with us and has been for the last 18 years. The Red River in Fargo has been above flood stage since it went over 18 feet in March. It went below flood stage for one day and then we got over four inches of rain and it went up to almost 23 feet. Six feet over flood stage.Today it is sitting at around 23 feet.
    The sad thing is that people who like to fish the mid town dam in Fargo can’t even get to the river as the park is still flooded. I know the Cat Fish, Walleyes and Northerners are just waiting for my hook and bait.

    Hey a couple of typos happen to us all.

  4. Question for Daryl Ritchison. I have heard that the ground in the northern valley is raising after all these years from being compressed from the glaciers. Do you think if this rise is large enough in the future, that the Red River will start flowing south? Then we would really have flood problems Eh?

  5. Bruce, in theory that will indeed happen, at least according to my geology professor in college. But it is still multiple thousands of year in the future and another ice age will likely recompress the crust before then. I think we’re safe. I see there are still some formatting errors above. So we’re all making typos it seems.

  6. I have hopefully eliminated any typos above. I wrote it in a rush a few days ago and should have fine tuned it before it was posted. I wanted to get the graphics and data out quickly as I thought others would find it as interesting as I did. Let me know if any more corrections are required.

  7. Mr. Ritchison,
    Yes the RRV is rising but at very slow rate. Much more disturbing is the climatic shift in central north America. Record level droughts followed by record floods. Hurricane force ‘lows’ traveling across the northern USA and Canada. Talk with any agricultural producer in the area and they will will agree that these times are, weather-wise, outside of the norm. To quote one from the north country, albeit the range rather than the valley, “the times they are a changing”
    Tom

  8. Thanks for compiling this information. It lays out the situation really well for a lot of the wet areas.

  9. Daryl in recent conversations with friends and co-workers we have been discussing whether the increase in rainfall volume in the red river valley, particularly the northern valley is due to larger volume of water in Devils Lake. No science to back up this idea just wondering if there could be anything to this notion. Or does most of our rain moisture come from much further away?

  10. I’m curious if anyone has extrapolated the weather circumstances that led to the flooding of the Souris to no-longer-record levels 130 years ago? What was going on then, and what changed? Obviously there were no dams to hold back the water and release it in massive amounts… how did that flood happen, how long did it take? What do we know about it compared to this year?

  11. Pat,

    Although Devils Lake flooding is a horrible situation, it’s scope is just too small to have any influence on the weather (besides a very local cooling near the lake). About 80% of our moisture comes from the Gulf of Mexico, the other 20% or so from the Pacific.

    ___________________________________________

    The exact reasoning for why this area has been wetter is recent years isn’t fully understood, but it has happened dozens of times in the past centuries. It’s not abnormal, it’s actually a normal part of our climate, just like droughts are normal.

    Our climate isn’t changing, instead this is part of our climate. 1881 through 1910 were actually wetter in Fargo than the past 30 years. In the early 1800s Devils Lake was also very high. Devils Lakes has also flowed in the the Sheyenne River several times in the past few thousand years.

    We all want things to be “normal” all the time, but the reality is, extremes are our “normal” in this area.

  12. Pingback: Tracking Flooding/Droughts in the US – 2008 to 2011 — Titan Outlet Store

  13. Devils Lake is up 53′ in 60 years. Minot has a record flood despite the reservoirs created along the Souris that were supposed to keep this from happening. Fargo is experiencing major flooding almost every year now. The polar caps are melting. The ocean is warming. Warm water evaporates faster and warm air holds more water. Recently, 97% of climate scientists held that climate change is real and exacerbated by man, compared to about 60% of meteorologists. Apparently, the more one knows about climate, the more one believes in climate change. Is it true that Pope Urban the 8th said ‘look out the window, Galileo, any idiot can see the world is flat?’

  14. Bill, just so you know that 97% of climate scientists was survey of about 60 people, all known to have leanings that way. It’s a stat with no basis. This area has been even wetter in the past. It’s part of our climate, just like droughts are. Everything that is happening now has happened in the very recent past.

Leave a Reply

Your email address will not be published.

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>