Vanna C. Chmielewski- Feb 1- Convective Meteorology

Anomalous charge structures, those containing net positive charge in the mid-levels (-10 °C to -30 °C) and promoting positive cloud-to-ground flashes, have been associated with updrafts producing abundant supercooled liquid water. However, surrounding the updraft core many processes act to limit supercooled liquid water content (e.g. locally lower updraft velocities,

Start

February 1, 2019 - 3:00 pm

End

February 1, 2019 - 4:00 pm

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120 David L Boren Blvd, Norman, OK 73072   View map

Anomalous charge structures, those containing net positive charge in the mid-levels (-10 °C to -30 °C) and promoting positive cloud-to-ground flashes, have been associated with updrafts producing abundant supercooled liquid water. However, surrounding the updraft core many processes act to limit supercooled liquid water content (e.g. locally lower updraft velocities, ingestion of cloud ice, entrainment) which could influence local lightning polarity and ultimately the flash sizes and rates around the updraft region. Two supercells with anomalous electrification characteristics were examined in North-Central Oklahoma – the first during an intensification phase on 29-30 May 2012 near Kingfisher and the second throughout an entire mesocyclone cycle on 29-30 May 2004 near Geary. The storms were analyzed with the Oklahoma Lightning Mapping Array (OKLMA), dual-Doppler and diabatic Lagrangian analysis (DLA) for metrics relevant to non-inductive collisional charging such as temperature and supercooled cloud water mixing ratio. DLA-based graupel/hail trajectories within the Kingfisher storm additionally provide information on where respective particle electrification occurred. Both storms contained spatially distinct regions of electrification around the updraft cores including localized updraft regions producing normal vertical charge structures, opposite the overall structure. The production of these regions and the extent that other local updraft variations produced observable changes in electrification will be discussed.

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meteorology.ou.edu