Lemon & Doswell

31 Years Later

Now, 31 years after the revised supercell model was established, we take a look at that paper again entitled “Severe Thunderstorm Evolution and Mesocyclone Structure as Related to Tornadogenesis”.  The paper in 1979 surveyed and incorporated many of the established characteristics of the supercell storm as presented in case studies as well as other review articles of the time.  However, the paper only relied on previously published data and studies.  No new data was used.  But the study was comprehensive synthesizing all available data including surface, upper air, “conventional” and Doppler radar, and visual data.  Considerable attention had been placed on these storms in the literature prior to 1979 because they had been shown to be the archetypical tornado and other severe weather producers. The intent of this study was to examine in detail the structure of the mesocyclone and its parent storm, the supercell, in an attempt to better understand and establish the storm and its relationship to tornadoes and tornadogenesis.   In particular, we noted the existence of the Rear Flank Downdraft (RFD) with these storms as well as its importance to tornadogenesis.  Further, in contrast to the primary supercell model of the day, that of Browning, we noted that the storms were not “steady state” after all, but often had a predictable evolution from inception to decay.  Storm gust front locations and trailing micro “airmasses” also seemed important to the storm structure.  Remarkably, the mesocyclone appeared to be a storm scale replica of the extra-tropical cyclone.

Because that model still stands today and is the standard by which other studies and models are compared, I want to take another look at how the model might change today if Lemon and Doswell were to revisit the study.  But I will also trace some of the detail changes or additions that have been suggested.  Finally, I’ll also relate some personal anecdotes concerning the model and its publication.