Thursday, April 4, 2013

Summer 2013 - A New Record Drought for America?


We tend to associate drought with those hot, dry summer days that we commonly experience in June, July and August and tend to expect that wetter conditions throughout the fall, winter and spring will recharge the ecosystem.  Last summer's drought, in particular, was one of the worst on record as shown on this Drought Monitor map from September 4th, 2012, right at the end of the hottest weather of the summer growing season:


At that time, the drought severity over 6.14 percent of the Contiguous United States was classified as suffering from exceptional drought conditions (D4) and 42.48 percent was classified as either severe, extreme or exceptional (D2, D3 and D4).  Only 22.54 percent of the United States landmass was considered drought-free.

Now, let's look at the drought conditions at the end of March 2013:


You'll notice that much of the centre of the American continent that suffered from drought throughout the summer of 2012 is still suffering from drought.  At the end of March, 5.1 percent of the Contiguous United States was classified as suffering from exceptional drought conditions and 35.19 percent was classified as either severe, extreme or exceptional.  Just over one-third (34.96 percent) of the United States landmass was considered drought-free.  Despite having passed through what is normally the seven highest precipitation months, the moisture situation is still dire.

Let's look back in time and see what "normal" March drought conditions look like.  Here's the drought map for the end of March 2011:


Only 18.22 percent of the landmass was classified as suffering from severe, extreme or exceptional drought and the area affected was found in the normally dry belt along the southern border of the nation.

Here's the drought map for the end of March 2010:


Only 2.0 percent of the American landmass was classified as suffering from severe, extreme or exceptional drought.

Lastly, here's the drought map for the end of March 2009:


Texas was suffering from a fairly large area of exceptional drought conditions that made up a total of 0.62 percent of the contiguous American landmass.  Despite that, only 7.99 percent of the total contiguous landmass was classified as suffering from severe, extreme or exceptional drought.

Here is a graph that looks at the drought record back to the beginning of the new millennium, showing how severe the drought has been over the past year and a half compared to conditions over the past 12 years:


Here is NOAA's precipitation prediction for the next three months with the area shaded in light brown predicted to experience below normal levels of precipitation:


Lastly, here is NOAA's temperature prediction for the next three months with the area coloured in various shades of orange experiencing above normal temperatures:


This could well be shaping up to be a record drought year given that large areas of the United States are already experiencing extremely low moisture levels:.  At some point, poor growing conditions are going to have a very painful impact on food prices as crops continue to fail and this situation...


...could become even worse in 2013.

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