Proposed Conceptual Taxonomy for Proper Identification and Classification of Tornado Events

Abstract

A practical approach is recommended for identifying and archiving tornado events, based on the use of definitions that label all vortices as either type I, II, or III tornadoes. This methodology will provide a more meaningful tornado climatology in Storm Data, which separates and classifies all vortices associated in any manner with cumuliform clouds. Tornadoes produced within the mesocyclone of discrete supercell storms, with strong local updrafts (SLUs), will be classified as type I tornadoes. Frequently, these type I tornadoes result from the interaction of the SLU with strong rear-flank downdrafts (RFDs), or with shear vortices in the PBL. Tornadoes produced in association with quasi-linear convective systems (QLCS) will be classified as type II tornadoes (including cold pool, rear-inflow jets, bookend, and mesovortex events along the line). All other vortex types (including landspouts, waterspouts, gustnadoes, cold air vortices, and tornadoes not associated with mesocyclones or QLCS) will be labeled as type III tornadoes. A general discussion is provided that further clarifies the differences and categorization of these three classifications (which encompass 15 tornado species), along with a recommendation that NOAA adopt this taxonomy in operational and data archiving practices. Radar analysis and field observations, combined with storm-scale meteorological expertise, should allow for the official ''typing'' of tornado reports by NOAA personnel. Establishment of such a climatological database in Storm Data may be of value in assessing the effects (if any) of twenty-first-century global warming on U.S. tornado trends.

The Carr Fire Vortex: A Case of Pyrotornadogenesis?

“…Specifically, the latent heating within the pyroCb and subsequent vertical stretching of antecedent near‐surface vorticity are key ingredients to the vortex formation. These factors differentiate this vortex from ordinary FGVs and are consistent with theories for nonmesocyclonic tornadogenesis in environments with high cloud bases and steep lapse rates (Agee & Jones, ; Davies, ; Wakimoto & Wilson, ).…”

Tornadic environments in the Iberian Peninsula and the Balearic Islands based on ERA5 reanalysis

“…Tornadoes can be formed in different environments depending on the convective mode (e.g., supercells or mesoscale convective systems; see, for example, Agee and Jones (2009), Grams et al . (2012), Markowski and Richardson, (2009), Thompson et al .…”

Finescale Radar Observations of Tornado and Mesocyclone Structures

“…), and ''type 3'' (landspouts, waterspouts, gustnadoes, hurricane eyewalls, and anticyclonic vortices near stronger cyclonic vortices). This taxonomy was criticized as not being sufficiently dynamically based [see comment and reply to AJ09 by Markowski and Dotzek (2010) and Agee and Jones (2010), respectively].…”