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Article
Sensitivity of a Bowing Mesoscale Convective System to Horizontal Grid Spacing in a Convection-Allowing Ensemble
Atmosphere
  • John R. Lawson, Iowa State University, NOAA/OAR/National Severe Storms Laboratory, and Cooperative Institute for Mesoscale Meteorological Studies
  • William A. Gallus, Jr., Iowa State University
  • Corey K. Potvin, NOAA/OAR/National Severe Storms Laboratory and University of Oklahoma
Document Type
Article
Publication Version
Published Version
Publication Date
4-14-2020
DOI
10.3390/atmos11040384
Abstract

The bow echo, a mesoscale convective system (MCS) responsible for much hail and wind damage across the United States, is associated with poor skill in convection-allowing numerical model forecasts. Given the decrease in convection-allowing grid spacings within many operational forecasting systems, we investigate the effect of finer resolution on the character of bowing-MCS development in a real-data numerical simulation. Two ensembles were generated: one with a single domain of 3-km horizontal grid spacing, and another nesting a 1-km domain with two-way feedback. Ensemble members were generated from their control member with a stochastic kinetic-energy backscatter scheme, with identical initial and lateral-boundary conditions. Results suggest that resolution reduces hindcast skill of this MCS, as measured with an adaptation of the object-based Structure–Amplitude–Location method. The nested 1-km ensemble produces a faster system than in both the 3-km ensemble and observations. The nested 1-km simulation also produced stronger cold pools, which could be enhanced by the increased (fractal) cloud surface area with higher resolution, allowing more entrainment of dry air and hence increased evaporative cooling.

Comments

This article is published as Lawson, John R., William A. Gallus, and Corey K. Potvin. "Sensitivity of a Bowing Mesoscale Convective System to Horizontal Grid Spacing in a Convection-Allowing Ensemble." Atmosphere 11, no. 4 (2020): 384. DOI: 10.3390/atmos11040384. Posted with permission.

Creative Commons License
Creative Commons Attribution 4.0
Copyright Owner
The Author(s)
Language
en
File Format
application/pdf
Citation Information
John R. Lawson, William A. Gallus and Corey K. Potvin. "Sensitivity of a Bowing Mesoscale Convective System to Horizontal Grid Spacing in a Convection-Allowing Ensemble" Atmosphere Vol. 11 Iss. 4 (2020) p. 384
Available at: http://works.bepress.com/william_gallus/82/