Drought or Deluge?

In a chapter from my potential book, World of Thermo, in an allegorical but amusing way, I told the story of three black birds on top of a wind turbine musing over a new, or second Dust Bowl in the 2020’s here: http://www.guyonclimate.com/2017/03/26/world-of-thermo-wind-whistler-story/

A second Dust Bowl would not be a laughing matter, however. The first one during the 1930’s was the first climate driven mass exodus in U.S. history. Approximately one quarter of the affected population fled west from the Plains to California and elsewhere, which was nearly 2.5 million people.  Poor agricultural practices were partially to blame, but natural factors did coalesce to produce a great drought over the nation’s heartland.

Before this winter speculation was beginning that California was starting to undergo a dust bowl of their own after a record five year drought. Now too much precipitation produced by onslaughts of Pacific storms, at least temporarily, is that state’s problem. We know that a warming atmosphere due to carbon pollution holds more moisture, and that moisture is being released all over the planet, from time to time, in heavier deluges. So what will be the future for your area of the world….drought, deluge, or a bit of both?

Today Dr. Michael Mann came out with this report, which is well worth reading, on attribution: http://www.nature.com/articles/srep45242

Summarizing from the introduction it would appear that extreme events, such as the 2003 European heat wave, are interrelated between carbon pollution affected jet streams, changes in soil moisture, sea surface temperatures, and rapid Arctic warming. There is a stew of different factors pulling where you live at the moment towards a wetter or drier climate. So what about this week’s topic, drought? Dr. Mann’s report confirms that during the warm months the jet is pulling further north allowing for statistically more widespread drought.

Dire predictions of different regions around the country becoming deserts or more desert-like in the last couple of decades have gone by the boards, thankfully. I often refer to forecasts, such as my home city of Atlanta running out of water back in 2008, as alarmism. So what I present here is just “educated speculation” based on my 30+ years experience in the meteorology/climate business.

What we have been seeing since the planetary warming trend commenced in earnest in 1980 are prolonged periods, sometimes lasting around five years, of drought followed by “quick relief”. Such was the case recently in California, and the southern Plains and Texas. Going from drought to deluge fits in with current climate models, which are becoming more regionalized. I did note that the jet stream pattern was locked in place for five years to produce the droughts for those two areas of the country.

Droughts lasting for a growing season or two usually begin in the spring and break after the predominant  jet stream pattern abruptly changes. This year I speculate that there may be a drought from the central and southern Plains into portions of the Southeast given dry conditions already in place, warm soil, and no snow cover over the southern portion of the Midwest. The following is the latest U.S. Drought Monitor:

20170321_usdm_home

Duh right? Drought conditions are already present in the area where I just made a forecast for 2017. But what about a second Dust Bowl developing in the Plains? I nearly came to the belief that this was happening before a change of the weather pattern broke the 2010-2015 Plains drought. If an area of the country becomes desert, it truly must experience climate change.

States, such as California and Georgia, where recent doom and gloom forecasts of desertification bombed, are located near large bodies of water…the Pacific, Gulf of Mexico and Atlantic. If the jet becomes active enough, bountiful precipitation will fall in California and my home state, Georgia. In California’s case later this century the jet may not dip far south enough to provide much drought relief.

My best guess is that there could be another Dust Bowl in the western high Plains area if all drying factors come together for more than five years. The area from west Texas northward through western Kansas and Nebraska is farthest away from large bodies of water in the U.S. outside of the Desert Southwest. The Dakotas are also far from their nearest big moisture source, the Gulf of Mexico, but it would appear that the jet stream will squeeze out precipitation there for decades to come due to their more northern latitude location.

Some climate models do forecast that the Desert Southwest will spread through the southern Rockies into portions of the Plains.  One study from 2016 is noted here: https://link.springer.com/article/10.1007%2Fs00704-016-1773-2

One point though. The increasingly constant disruption of agriculture and infrastructure, such as happened to the Oroville Dam in California, due to this new “drought/deluge” world will put great strains on society regardless of whether areas experience true climate change leading to desertification in the United States.

We will look at the tie in between record heat and droughts on the next post.

The Climate Guy

 

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