Lightning during Two Central U.S. Winter Precipitation Events

Abstract

Network-detected cloud-to-ground lightning coincident with mainly frozen precipitation (freezing rain, sleet, snow) was studied over the central United States during two outbreaks of arctic air in January 1994. During the first event, the ratio of positive to total flashes was 59%, flashes were few and disorganized in area, and no surface observer reported thunder. For the other event the ratio was 52% during the first few hours in subfreezing surface air, then decreased when flashes formed in the nearby region above freezing. Also, flashes in this case were linearly aligned and coincided with conditional symmetric instability; thunder was heard infrequently by surface observers. On radar, reflectivity cores grew from weak to moderate intensity within a few hours of the lightning during both cases. Echo area increased greatly before flashes in one case, while the area increase coincided with flashes in the other. Some base-scan reflectivities were strong in both thunderstorm regions due to the radar beam intersecting the melting level. Regions with lightning often could be identified better by high echo tops than reflectivity. Analyses on the scale of one or two states diagnosed the strength of low-level warming that contributed to formation of thunderstorms and significant frozen precipitation. Quasigeostrophic analyses showed that 850-mb temperature advection and 850-500-mb differential vorticity advection were similar in magnitude in the lightning area during both events. Once convection formed, lightning and echo-top information identified downstream regions with a potential for subsequent frozen precipitation.

A Case Study of Severe Winter Convection in the Midwest

“…The historical research focus on western Japan has yielded a robust body of work (see Rakov and Uman 2003 for a thorough review) with an emphasis on surface-influenced events that are akin to those that form downstream of the North American Great Lakes. Also, our results differed from the findings of Holle and Watson (1996), who studied two central United States storms that exhibited lightning with winter precipitation and found lightning behavior similar to that on the east coast of Asia, where the dominant polarity detected is positive.…”

Global distribution of winter lightning: a threat to wind turbines and aircraft

“…Another cause of winter storms in Canada and the central USA are outbreaks of Arctic fronts (e.g., Holle and Watson, 1996) in which cold Arctic air masses move from north to south, meeting warm humid air from the Gulf of Mexico. Along these cold fronts thunderstorms are formed in the warm elevated layer, producing frozen precipitation at the surface.…”

A Diagnostic Examination of the Eastern Ontario and Western Quebec Wintertime Convection Event of 28 January 2010

“…Other work has been mostly limited to examining the dynamic and thermodynamic properties of specific coldseason events involving lightning or severe weather (Holle and Watson 1996;Schultz 1999;Hunter et al 2001;Trapp et al 2001;van den Broeke et al 2005;Corfidi et al 2006). In particular, Schultz (1999) analyzed the difference between lake-effect events with and without lightning for both northern Utah and western New York State, two regions susceptible to frequent lake-effect events (Niziol et al 1995;Steenburgh et al 2000;Steenburgh and Onton 2001).…”