Kansas City in 2013: Cool and continue dry; rainfall down 20″ for the decade

Kansas City, like most of the U.S., had a cool year, with the city coming in around a degree and a half below average.  Temperatures reached as high as 100, late in the Summer, on September 8th, and the coldest reading was -2 on December 24th.  It had been 1,047 days since the last reading below zero.  There were only 33 days with a high of 90 or greater, compared to 69 in 2012 and 49 in 2011.  31 days were recorded where the high temperature remained below freezing and there were 122 days with lows below freezing.  2 days recorded below zero temperatures.

Kansas City 2013 Temperature stats.

Kansas City 2013 Temperature stats.

The year alternated cool and warm periods, and the year began on a warm note, which had started in August 2012 and continued until mid February.  This was approximately a  120 day period of warmth, which extended through the first 45 days or so of 2013. The weather pattern flipped at that point and a 100 day cool period began, lasting through early July.  A temporary burst of warmth re surged early in the summer, then gave way to a cooler period for mid summer.  A second 45 day period of warmth ran from Mid August until early October. This stretch included the year’s hottest temperature, on September 8th.  An extended and often sharply colder pattern took hold after that and lasted beyond the year’s end.

2013 was characterized by long stretches of warm and cool periods, but the predominate mode was cool.

2013 was characterized by long stretches of warm and cool periods, but the predominate mode was cool.

Rainfall, or the prolonged lack of rainfall, was the big story in KC for 2013.  Although the year finished 4″ below average, which does not sound that bad, that comes on the heels of a very dry 2012 and adds up to nearly a 20″ deficit for the 2010s to date.

Kansas City ended December below average in terms of precipitation. 2013 was also below average. Four out of 12 months in 2013 were below average and since the decade began, there have been only 18 of 48 months with above average precipitation.  Kansas City continues to run a considerable long-term deficit and is -4.38" for 2013, -20.96 for 2012-2013, -22.90 for the period 2011-2013 and is -19.85 for the 2010s decade to date.

Kansas City ended December below average in terms of precipitation. 2013 was also below average. Four out of 12 months in 2013 were below average and since the decade began, there have been only 18 of 48 months with above average precipitation. Kansas City continues to run a considerable long-term deficit and is -4.38″ for 2013, -20.96 for 2012-2013, -22.90 for the period 2011-2013 and is -19.85 for the 2010s decade to date.

KC fell behind right out of the gate in January but made up ground by the end of February.  For the remainder of Spring and early summer, KC managed to remain near average, sometimes a little behind and sometimes a little ahead. That changed in the summer. The nightly pattern of recurring thunderstorms which deliver much of the summer rains to KC were largely absent once again.  2012, had them tracking well to the north, while 2013 saw them tracking just…just to the west and south. 50-100 miles in that direction yearly rains were very much above average.  Many long dry stretches were the norm for the rest of the year and the city consistently retained a 3-5″ rainfall deficit from that point to the close of the year.

Kansas City 2013 rain and snowfall.

Kansas City 2013 rain and snowfall.

Taking a wider view of the region; here is a look at the average annual rains, departure (or difference) from average and the percent of average rains for 2013.

Average yearly rains over Missouri and S Illinois.

Average yearly rains over Missouri and S Illinois.

Observed precipitation for 2013. The darkest reds depict 60" rainfall totals over the SW and SC Missouri Ozarks and parts of SE Illinois. 50" totals were over much of the rest of SW Missouri due to repeating summer rains and SE Missouri and SE Illinois thanks, in part to heavy December rains. Northern and NW Missouri to just NW of KC had 25 to 40" of rainfall with a small area of NW and NE Missouri having 20-25" of rainfall.

Observed precipitation for 2013. The darkest reds depict 60″ rainfall totals over the SW and SC Missouri Ozarks and parts of SE Illinois. 50″ totals were over much of the rest of SW Missouri due to repeating summer rains and SE Missouri and SE Illinois thanks, in part to heavy December rains. Northern and NW Missouri to just NW of KC had 25 to 40″ of rainfall with a small area of NW and NE Missouri having 20-25″ of rainfall.

This graphic clearly shows which areas received the heaviest rains and which areas were missed in large part.

This graphic clearly shows which areas received the heaviest rains and which areas were missed in large part.

Percent of average rainfall.

Percent of average rainfall.

This chart illustrates how KC has entered a long term dry pattern and shows the cumulative surplus or deficit in rainfall from Jan 1, 2010 to Dec 31, 2013. It is easy to see the downhill slide starting in early 2012 and even though the slide has leveled off, we are still trending downward.

This graphic shows the running total of how far above or below average Kansas City is for precipitation for the 2010s decade.

This graphic shows the running total of how far above or below average Kansas City is for precipitation for the 2010s decade.

We’ll likely need several years of wet weather to reverse this trend, however oceanic conditions tilt the odds in favor of summertime drought and winter dryness and this may be a pattern which holds several more years.

Average drought frequency for the Midwest/Plains for a negative Pacific multidecadal oscillation (-PDO) and a positive Atlantic multidecadal oscillation (+AMO).  These oscillations slowly change states over a period of 10-20 years.  The current pattern, became established in the late 2000s.  The +AMO has been in place since 1995, while the -PDO since 2008. In its current state, the odds are tilted towards drought in Kansas City 30% of the time or 3 in every 10 years.  When the +AMO becomes a -AMO, which may occur shortly, drought frequency drops to near average (2 in every 10 years or once in every 4 years.)

Average drought frequency for the Midwest/Plains for a negative Pacific multidecadal oscillation (-PDO) and a positive Atlantic multidecadal oscillation (+AMO). These oscillations slowly change states over a period of 10-20 years. The current pattern, became established in the late 2000s. The +AMO has been in place since 1995, while the -PDO since 2008. In its current state, the odds are tilted towards drought in Kansas City 30% of the time or 3 in every 10 years. When the +AMO becomes a -AMO, which may occur shortly, drought frequency drops to near average (2 in every 10 years or once in every 4 years.)

Most of the weather stories of note revolved around rain and snow.  A more or less snow-free winter sharply turned in February with two major storms a week apart.  The first dumped these snow totals, with the snow accompanied by thunder and lightning:

Snowfall totals from the winter Storm of February 21, 2013.

Snowfall totals from the winter Storm of February 21, 2013.

The second these totals, also with thunder and lightning:

The second major snow storm dumped these snow totals on the region.

The second major snow storm dumped these snow totals on the region.

This graphic shows the snow depth following these two storms:

Total snow on the ground following the two February back to back snowstorms.

Total snow on the ground following the two February back to back snowstorms.

The year’s final big snow hit on March 23-24, and while not as big as the previous two storms, it was enough to create serious issues due to the heavy and wet snow. Lightning and thunder were again reported.

The March 23-24 snowstorm, the third and final big snow of the year.

The March 23-24 snowstorm, the third and final big snow of the year.

Here is a look at some of the other weather highlights of 2013:

Heavy rains just miss KC:

Repeated rains in August bypassed the city just to the west and south,

Repeated rains in August bypassed the city just to the west and south.

Summer makes a late, and powerful, entrance:

Oppressive heat was late arriving to the region, not taking hold until mid August and after.

Oppressive heat was late arriving to the region, not taking hold until mid August and after.

The weather map from the hottest day of the year, September 8, 2013.

The weather map from the hottest day of the year, September 8, 2013.

Late October’s first freeze:

The first freeze hit a little ahead of schedule on October 25th. Low temperatures that morning.

The first freeze hit a little ahead of schedule on October 25th. Low temperatures that morning.

Typhoon Haiyan helps fuel a change in our weather pattern mid November:

A record breaking western Pacific Typhoon 8,500 miles away helped force a change in our jet stream pattern to turn the corner to a much colder regime.

A record breaking western Pacific Typhoon 8,500 miles away helped force a change in our jet stream pattern to turn the corner to a much colder regime.

December snowfall:

Total snow from the event with 8" or more from far NE Kansas through far NW Missouri and on into Iowa. Kansas City was on the outer edge of the 4-8" band with rapidly decreasing totals southeast toward Lee's Summit and points beyond. Around .1" to .2" of ice underlies the snow in KC with more ice SE and less NW.

Total snow from the event with 8″ or more from far NE Kansas through far NW Missouri and on into Iowa. Kansas City was on the outer edge of the 4-8″ band with rapidly decreasing totals southeast toward Lee’s Summit and points beyond. Around .1″ to .2″ of ice underlies the snow in KC with more ice SE and less NW.

END

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