Differing trends in United States and European severe thunderstorm environments in a warming climate

rdale

EF5
Mar 1, 2004
7,255
796
21
50
Lansing, MI
skywatch.org
CIN is a bad thing if you like thunderstorms...

Long-term trends in the historical frequency of environments supportive of atmospheric convection are unclear, and only partially follow the expectations of a warming climate. This uncertainty is driven by the lack of unequivocal changes in the ingredients for severe thunderstorms (i.e. conditional instability, sufficient low-level moisture, initiation mechanism and vertical wind shear). ERA5 hybrid-sigma data allows for superior characterization of thermodynamic parameters including convective inhibition, which is very sensitive to the number of levels in the lower troposphere. Using hourly data we demonstrate that long-term decreases in instability and stronger convective inhibition cause a decline in the frequency of thunderstorm environments over the southern United States, particularly summer. Conversely, increasingly favourable conditions for tornadoes are observed during winter across the Southeast. Over Europe, a pronounced multidecadal increase in low-level moisture has provided positive trends in thunderstorm environments over south, central and north, with decreases over the east due to strengthening convective inhibition. Modest increases in vertical wind shear and storm-relative helicity have been observed over northwestern Europe and the Great Plains. Both continents exhibit negative trends in the fraction of environments with likely convective initiation. This suggests that despite increasing instability, thunderstorms in a warming climate may be less likely to develop due to stronger convective inhibition and lower relative humidity. Decreases in convective initiation and resulting precipitation may have long-term implications for agriculture, water availability and the frequency of severe weather such as large hail and tornadoes. Our results also indicate that trends observed over the United States cannot be assumed to be representative of other continents.

 

Jeff Duda

Resident meteorological expert
Staff member
Supporter
Oct 7, 2008
3,326
2,067
21
Broomfield, CO
www.meteor.iastate.edu
Looks like it could be an interesting read...but at 51 pages, downloaded for later reading.
This version is in "early online release" (EOR) form...very much immature/primitive compared to what it will look like once formally published. In EOR form there are tons of extra pages for a reference list, list of figure captions, one figure per page (even if the rendered figure does not require a full page in the published version) and other assorted aspects you won't read. The actual paper is only 500 lines (28 double spaced pages), which is actually on the short side for full-length scientific articles. It probably won't take as much time as you think.
 

James K

EF4
Mar 26, 2019
305
117
6
Colorado
@Jeff Duda:
Yep, I can see what you mean there. Started reading it.
I put it on my tablet so I could bring it to work for lunchtime reading material (usually I'd bring a magazine, but the tablet does work nicely for pdf's :) )