Study of Synoptic-Scale Tornado Regimes

Abstract

The significant tornado parameter (STP) has been used by severe-thunderstorm forecasters since 2003 to identify environments favoring development of strong to violent tornadoes. The STP and its individual components of mixed-layer (ML) CAPE, 0-6-km bulk wind difference (BWD), 0-1-km storm-relative helicity (SRH), and ML lifted condensation level (LCL) have been calculated here using archived surface objective analysis data, and then examined during the period 2003-2010 over the central and eastern United States. These components then were compared and contrasted in order to distinguish between environmental characteristics analyzed for three different synoptic-cyclone regimes that produced significantly tornadic supercells: cold fronts, warm fronts, and drylines. Results show that MLCAPE contributes strongly to the dryline significant-tornado environment, while it was less pronounced in cold-frontal significant-tornado regimes. The 0-6-km BWD was found to contribute equally to all three significant tornado regimes, while 0-1-km SRH more strongly contributed to the cold-frontal significant-tornado environment than for the warm-frontal and dryline regimes.

Contrasting Responses of Hailstorms to Anthropogenic Climate Change in Different Synoptic Weather Systems

“…The study region is the central US because of the highest occurrences of hail in the US (Cintineo et al, 2012). While previous severe weather taxonomies in the literature are numerous for this region, they have generally focused on tornadoes (e.g., Anderson-Frey et al, 2017;Brooks et al, 1994;Garner, 2013) or flash flooding/Mesoscale Convective Systems (e.g., Maddox, 1983;Song et al, 2019;Yang et al, 2017). We turn to a general warm-season precipitation regime taxonomy in Wang et al (2019).…”