Summer Flood to a Trickle

In 1975, 26.30 inches of rain and melted snow was recorded.  At the time it was the 15th wettest year on record.  Much of the excessive rain that year occurred in June when 9.40 inches was recorded.  That June rain was even heavier south of Fargo and that lead to severe summer flooding on both the Red and Sheyenne Rivers among others.

With so much water, thoughts of water shortages was likely not on anyone’s mind that summer.  Yet, a year later, in 1976, the Red River in Fargo gradually stopped flowing.  Only 8.84 inches of rain and melted snow was recorded in Fargo Moorhead that year, with most of the region also receiving scant precipitation.   Plus, with summer temperatures finishing well above average, the lack of rain in combination with high evaporation rates led to many rivers running dry by that autumn.

From summer flood in 1975 to barely a trickle in 1976, such events in our climate are to be expected and it will likely occur again in the future.

 

First Half Records

Yesterday, I wrote about the huge range in precipitation amounts across Fargo Moorhead in recent weeks.  Rain totals from north metro to south metro has varied by as much as 5 inches in the past 5 weeks.  But because the official statistics are kept at the airport, the first six months of 2013 will go down as the wettest on record in Fargo Moorhead. 

In total, January through June the airport recorded 20.63 inches of rain and melted snow, that is nearly 2 inches greater than the previous record for that period set back in 2000 when 18.83 inches fell during that time frame. As a reference, last year, only 7.42 inches was recorded during the first half of 2012.  A vast majority of the rain this year occurred in May and June, principally from two events, the 4.62 inches on May 29 and 30 and the 3.96 inches that fell this past Tuesday Night into early Wednesday morning. 

In total 14.89 inches of rain fell at the airport these past two months which is more than fell during all of 2012. 

The Static Illusion

There is no denying that Sandy caused horrific damage to the east coast.  Although many people were surprised that such an event hit where it did, most meteorologists on the other hand were instead surprised that area was not hit again sooner.  In this space and during many of my public talks I have mentioned that our weather patterns in recent years have transitioned to what occurred in the 1950s and 1960s.

The 1950s recorded several hurricane strikes along the east coast with many causing devastation on par with Sandy.  With a much higher population base in combination with increased land use changes along the coast, although exceptionally heart breaking to see, the amount of damage was not unexpected.

Until humans realize that the boundary between land and ocean (or lake and rivers) is not static we are going to continue to experience such destruction in the future, as if we want to admit it or not, the forces of nature can not be controlled.

Pumping Water

I posted this to my twitter account (@darylritchison), but I thought I would post it here quickly as well.  But New Orleans, LA has the ability to pump nearly 50,000 cfs of water out of the city.  Last I heard they were near 70% capacity today.  How much water is that?  In Fargo Moorhead during the 2009 flood, that was a close call for the city, the Red River peaked at 29,500 cfs locally.  So in other words, the pumps in New Orleans could have literally pumped the Red River dry with capacity left over.  Technology is a remarkable thing… when it works.

 

The End of Wet?

This summer has many parallels to what occurred in 2006.  You may recall that 2006 was also a warm dry summer in the region.  That summer there were many comments about how the wet cycle must have finally ended and that drier years were ahead.

That year I was asked frequently if I thought our string of wet years was over and my response was to ask me in five years.  My reasoning was it would take at least that long before there would be any conclusive evidence that a different precipitation pattern had developed.  Certainly, the wet pattern would end eventually, and it may end quickly, but one dry spell does not necessarily mean the end of a long term pattern.  2006 turned out to be just an aberration as the following years were very wet once again, with devastating flooding in 2009, 2010, and 2011.

Six years later, it is dry again with the same question being asked and my answer is still the same, ask me in five years.

One Year Ago, The Minot Flood

I wrote this article about one year ago.  I am reposted it as the one year anniversary of this devastating event is upon us.

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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.

 

Dry Buster

A week ago much of Minnesota and some portions of eastern North Dakota were listed as either abnormally dry or in minor (D1) drought conditions.  That changed quickly last week in central and eastern Minnesota when 3-5 inches of rain fell prompting flood warnings to be issued.  Yet, that system stayed to our east keeping the local area dry and still waiting for rain.  Our turn came on Saturday Night into Sunday morning when much of west central Minnesota recorded 2-4 inches of rain with localized higher totals.

Fargo Moorhead ended up right on the edge of that system with much of Moorhead receiving over 2 inches of rain, where as parts of West Fargo up towards NDSU only recorded near 1 inch.

It was a reminder that our wet phase is likely not over and we continue to be just one heavy rain system away from being over saturated with flooding problems once again.

Red Decline

Since my blog post last week about the Red River being so high, it has dropped quite a bit, still high, but a much lower flow:  Here was that drop last week:

Here is the latest chart:

The Red River is now according to our weekend Meteorologist Rob Kupec at the lowest level in two years.  He did a story about the river and why it dropped in the past week.  You can find it online here:

http://www.wday.com/event/article/id/52844/


Dry But Wet

After a summer with the Red River in Fargo being above flood stage persistently, the past several weeks with the levels much lower has been a welcome sight.  Yet, by historical standards, the amount of water flowing through town is still extremely high.

For the past week, the Red River stage has consistently been just slightly above 16 feet.  Translated to cubic feet per second (cfs), approximately 2000 cfs is still flowing north as you read this.  The long-term median is only near 250 cfs.  So although the Red may look low in comparison to where we were, the amount of water in the river is still 8 times higher than normal for late September.

What this means is that even though the southern basin has been exceptionally dry in recent weeks, we are sadly still only one heavy rain event from the Red again reaching flood stage yet again.

The charts below are courtesy of gohydrology.org (I highly recommend reading this site).  Thanks for the graphics Robert!

A Touch Drier

Have you noticed that it isn’t raining as much the last couple of weeks?  We were already assured of above-average August rainfall when it rained 2.87 inches on the first day of the month.  After one more heavy rain and a few glancing blows, Fargo Moorhead stands at a little more than four inches for the month.

But the last significant rain to hit the city was back on August 6.  Lawns are starting to turn a little yellow and brown for a change.  But do not confuse short term dryness with truly dry weather.  The soil is only dry on the very top and rivers are still bank full.  Even if we have a dry fall season we will still be on pins and needles all winter worrying about the spring flood.  But the sunny and dry weather is at least a pleasant offering of normal, late-summer weather.

There might even be an opportunity to run along the bike path beside the river between midtown and Lindenwood, a path used only by catfish so far this summer