...A Dry and Hot Spring and Summer Continue...

 

2012 continues to be one of the driest and warmest years on record for many locations across the United States.  Locally, precipitation has been sparse since April 1st with many locations reporting the driest Spring season since the droughts of 1988 and the "dust bowl" years of the '30s.   In Kansas City, through July 17, 2012 (13.24") has been the driest year since 2006 (12.65") and 1989 (13.51").   The average precipitation through July 15th averages either side of 20 inches across Kansas and Missouri.  Some locations have a year to date precipitation total that is around average, many however are running significant departures from normal.

Average Precipitation From January 1-July 17 Precipitation Totals From January 1-July 17

Year to date departures from normal are running between 4 and 12 inches below normal in many locations with the hardest hit areas in southeastern Missouri where many locations are 12 to as much as 20 inches below normal. Short term precipitation totals describe a much different picture with substantial short term precipitation deficits. 

 Year to Date Departure from Normal Precipitation 90 Day Departure from Normal Precipitation
Year to Date Percent of Normal Precipitation 90 Day Percent of Normal Precipitation

 

Records and Normals:

Let's put the drought in a little bit of perspective and relate this dry spell to past dry spells. First, lets take a look at the exact weather conditions since the 1st of April at several sites across the local area. From the chart below, nearly all observation stations in the local area have received less than 60 percent of normal precipitation since April 1st.  Some sites, including those in and near the Kansas City metro, have only received 35 percent of normal precipitation with no measureable precipitation since June 22nd!

  

Site April Dep April Pcp May Dep May Pcp June Dep June Pcp July -17 Dep July -17  Pcp Apr-Jul Total Pcp Normal Total Dep % of Norm
Downtown  Kansas City
-2.37 1.34 -3.29 1.84 -3.28 2.24 -1.79 0.60 6.02 16.75 -10.73 36
Kansas City
-1.77 1.93 -4.23 1.00 -2.77 2.46 -2.55 0.10 5.49 16.81 -11.32 33
New Century (IXD) -2.65 1.22 -1.02 4.43 -4.46 1.59 -2.52 0.05 7.29 17.94 -10.65 41
Johnson County (OJC)
-2.44 1.55 -0.36 5.07 -4.27 1.51 -2.12 0.04 8.17 17.36 -9.19 47
Topeka -1.06 2.47 -2.33 2.58 -3.01 2.39 -1.56 0.67 8.11 16.07 -7.96 50
Lees Summit
-1.74 2.28 -1.38 4.31 -4.14 2.09 -2.64 T 8.68 18.58 -9.90 47
Sedalia 0.92 5.17 -3.27 1.42 -3.45 1.64 -1.97 0.54 8.77 16.54 -7.77 53
St. Joseph
-1.67 2.12 -3.75 1.67 0.09 4.27 -2.69 0.02 8.08 16.10 -8.02 50
Kirksville -0.46 3.38 -2.28 2.68 -2.69 2.09 -2.36 0.05 8.20 15.99 -7.79 51
Chillicothe -0.77 2.80 -2.23 2.89 -1.85 3.25 -1.81 0.41 9.35 16.01 -6.66 58

 

Kansas City: From a records perspective, the past 6.5 months have been one of the warmest and driest on record.  Here are some various records data for the Kansas City area:

 Lowest Precipitation Since January 1-July 17th

Lowest Precipitation Since April 1st-July 17th

Top 20 Driest Years of All-Time
Top 10 Driest Month of July Top 10 Wettest Months of July

  1    7.83     7/17/1936
  2   10.39    7/17/1934
  3   10.59    7/17/1988
  4   12.20    7/17/1918
  5   12.25    7/17/1890
  6   12.65    7/17/2006
  7   12.78    7/17/1971
  8   13.24    7/17/2012
  9   13.28    7/17/1911

  1    4.85    7/17/1911
  2    5.49    7/17/2012
  3    6.56    7/17/1936
  4    7.04    7/17/1988
  5    7.86    7/17/1901
  6    7.97    7/17/1980
  7    8.42    7/17/1953
  8    8.44    7/17/1934
  9    8.98    7/17/1906
 10   9.08   7/17/1890
  1   13.24   7/14/2012
  2   20.93   12/31/1953
  3   20.98   12/31/1936
  5   23.68   12/31/1976
  6   24.22   12/31/1988
  7   24.65   12/31/1963
  8   24.76   12/31/1901
  9   24.77   12/31/2002
 10   24.84   12/31/1937
 11   25.92   12/31/1956
 12   26.59   12/31/1971
 13   27.06   12/31/1932
 14   27.11   12/31/1933
 15   27.15   12/31/1934
 16   27.21   12/31/1966
 17   27.38   12/31/1943
 18   27.52   12/31/1954
 19   27.65   12/31/1972
 20   27.95   12/31/2003
  1    0.10    7/14/2012
  2    0.12    7/31/2003
  3    0.25    7/31/1975
  4    0.26    7/31/1983
  5    0.36    7/31/1936
  6    0.38    7/31/1916
  7    0.51    7/31/1999, 1935
  9    0.55    7/31/1929
 10   0.62    7/31/1970
  1   15.47    7/31/1992
  2   10.90    7/31/1993
  3   10.70    7/31/1958
  4   10.29    7/31/1969
  5    9.90    7/31/1950
  6    9.83    7/31/1965
  7    9.78    7/31/1920
  8    9.64    7/31/1895
  9    9.63    7/31/1902
 10    9.02    7/31/1961

 
Lets take a quick comparision of five important years in Kansas City history: 2012, the driest year on record, the last major drought in recent history in 1988, the wettest year on record of 1961 (for comparison) and two years of data from the "Dust Bowl" time period.  We'll place this chart side-by-side with a Haywood plot of running average yearly temperatures.  The Haywood plot is a means to visually describe the anomalous nature of the warm year in comparison to other years and the statistical average temperature.  It is clear that 2012 stands out on this measure of unusualness with a nearly 2 standard deviation departure from normal yearly values.  

 Year to Date Precipitation Comparison - Kansas City  Year to Date Temperature Haywood Plot - Kansas City

 

The persistence of the heat has also had a significant impact on drought conditions forming in the area.  Through July 15th, Kansas City has recorded 31 days of 90+ temperatures in 2012. The long term average since 1888 is 41 days in a calender year.  June was an especially warm month with 15 days of 90+ temperatures, double the typical June average of 7 and the most since 1988.   Looking at the next temperature threshhold of 100 degrees, reveals 2012 has recorded 9 days of 100+ temperatures, the most since 1988, 1980, and 1954. The historical average for 100 degree days in a year is 5, with more recent 30 year averages suggesting only 4 100 degree days per year.

Warmest Julys on Record
(average temperature)
Warmest Julys on Record Through July 17th
(average temperature)
Warmest April 1-July 17th

  1    88.3    7/31/1934
  2    87.7    7/31/1936
                       3    87.1    7/31/1901,  7/31/1954
  5    86.8    7/31/1935
  6    85.4    7/31/1955
  7    85.1    7/31/1980
  8    84.7    7/31/1939
                       9    83.3    7/31/1966,  7/31/1916

  1    89.2    7/17/1936
  2    87.9    7/17/1980
  3    87.8    7/17/1901
  4    87.7    7/17/1954
  5    87.2    7/17/1934
  6    87.0    7/17/1939
  7    85.1    7/17/1935
  8    85.0    7/17/1966
                   9    84.1    7/17/2012, 1938

  1    73.2    7/17/1934
  2    71.3    7/17/1936
  3    71.1    7/17/2012
  4    70.6    7/17/1963
  5    70.4    7/17/1954
  6    70.2    7/17/2006
  7    70.1    7/17/1911
  8    70.0    7/17/1970,  7/17/1962
 10    69.9    7/17/1955,  7/17/1939

The Drought Impact:

The 2012 drought is expected to have a major impact through the remainder of this year.  Much of the nation has been placed in drought status, with severe drought expanding in the central United States.  With rainfall deficits continuing to build each day, the long-term prognosis is that this drought may take some time to weaken.  Projections by the Climate prediction center estimate Kansas and Missouri will need in excess of 9 to 12 inches of rain to alleviate all drought symptoms.  Also taking a hit this summer are area streams and rivers.  Unbelievably, many areas which were experiencing extreme flooding during the Summer of 2011 are now dealing with below average river levels.  The images below represent the latest drought status in the country as well as the estimated precipitation requirements to return the area to normal soil moisture conditions.

Latest Drought Monitor Precipitation Requirements to Alleviate Drought
2011 vs. 2012 River/Stream Flow Levels

Drought Comparisons:

Precipitation totals across the central United States are beginning to rival other previous drought years such as in 1988, the 1953-55 drought, and even the "dust bowl" days of the 30s.  One of the measures of drought severity is the Palmer Drought Severity Index which uses temperature and rainfall information in a formula to determine dryness.  It has become the semi-official drought index.  So lets take a look at some of the more expansive and costly droughts in the countries history  in comparison to 2012.  

  May June July August
1934
1936  
1953  
1954
1980
1988  
2012    

 The drought monitor as we know it has been produced since 1999.  The plot below is a timeline of drought status across the state of Missouri from 2000-2012.  The most expansive areas of extreme droughts typically have fallen in the fall and winter timeframes.  The last expansive severe to even extreme drought in Missouri was recorded during the Summer and Fall of 2006.

 

Drought Outlook:

Many questions have been asked on what the future weather conditions hold and if there will be improvement in drought conditions in the near future.  Unfortunately, short term and long range predictions see little relief from the hot and dry conditions. Recent 8-14 day outlooks place a better than 50% probability of above normal temperatures through the remainder of July, with relatively high probabilities for below normal precipitation.  Looking forward to the remainder of the Summer and into the Fall season, the outlooks remain much the same.  Above normal temperatures are favorable, with climate signals pointing to equal chances of above or below normal precipitation.

8-14 temp probability

Latest CPC 8-14 day Temperature Outlook
Latest CPC One Month Temperature Outlook
Latest CPC 3 month Temperature Outlook

Latest CPC 8-14 Day Precipitation Outlook
Latest CPC One Month Precipitation Outlook
Latest CPC 3 Month Precipitation Outlook

So whats the latest drought outlook from the Climate Prediction Center heading into September? A continuation of drought is expected, with worsening conditions in portions of the Central United States.

U.S. Seasonal Drought Outlook


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