Radar Characteristics of Observed Supercell Thunderstorms Interacting with the Appalachian Mountains

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McKeown, K. (2021). Radar Characteristics of Observed Supercell Thunderstorms Interacting with the Appalachian Mountains. Unc Charlotte Electronic Theses And Dissertations.
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Abstract

Few studies have ventured to understand how supercell thunderstorms behave while interacting with complex terrain, though it poses a significant short-term forecasting problem. The few that have investigated this relationship tended to use small sample sizes, limited idealized simulations, or only focused on convection initiated by the terrain. This study aims to fill that gap by analyzing a large observed dataset of supercells interacting with the Appalachian Mountains. A total of 62 isolated supercells observed within the central and southern Appalachians between 2008 and 2019 were analyzed in this study. Each supercell was categorized based on the extent of their interaction with the terrain (either crossing or non-crossing); the majority (37) were classified as non-crossing, while a smaller minority (25) were classified as crossing. Analysis of storm tracks suggest that the extent of terrain effects on supercell maintenance are sensitive to the local topography. To better understand how supercells respond to variations in terrain, each supercell was tracked over its lifetime using GR2 software. Additionally, GIS was used to obtain additional information about the elevation, slope, angle of approach, and aspect. A variety of radar characteristics were collected for each of these storms, including reflectivity, velocity, maximum expected hail size (MEHS), echo tops, and mesocyclone intensity, depth and diameter. The mesocyclone parameters (depth, intensity and diameter) are the most different among crossing and non-crossing supercells. Crossing supercells typically have deeper, stronger, and wider mesocyclones. Based on the results, a list of radar-based thresholds were created to be used in operational settings.

Details
Author

McKeown, Katherine

Title

Radar Characteristics of Observed Supercell Thunderstorms Interacting with the Appalachian Mountains

Physical Description

1 online resource (131 pages) : PDF

Date

2021

Degree Granting Institution

University of North Carolina at Charlotte

Abstract

Few studies have ventured to understand how supercell thunderstorms behave while interacting with complex terrain, though it poses a significant short-term forecasting problem. The few that have investigated this relationship tended to use small sample sizes, limited idealized simulations, or only focused on convection initiated by the terrain. This study aims to fill that gap by analyzing a large observed dataset of supercells interacting with the Appalachian Mountains. A total of 62 isolated supercells observed within the central and southern Appalachians between 2008 and 2019 were analyzed in this study. Each supercell was categorized based on the extent of their interaction with the terrain (either crossing or non-crossing); the majority (37) were classified as non-crossing, while a smaller minority (25) were classified as crossing. Analysis of storm tracks suggest that the extent of terrain effects on supercell maintenance are sensitive to the local topography. To better understand how supercells respond to variations in terrain, each supercell was tracked over its lifetime using GR2 software. Additionally, GIS was used to obtain additional information about the elevation, slope, angle of approach, and aspect. A variety of radar characteristics were collected for each of these storms, including reflectivity, velocity, maximum expected hail size (MEHS), echo tops, and mesocyclone intensity, depth and diameter. The mesocyclone parameters (depth, intensity and diameter) are the most different among crossing and non-crossing supercells. Crossing supercells typically have deeper, stronger, and wider mesocyclones. Based on the results, a list of radar-based thresholds were created to be used in operational settings.

Genre

masters theses

Subjects--Topics

Meteorology

Degree

M.S.

Keywords

Observations
Radar
Supercells
Terrain

Subject Area

Earth Sciences

Advisor(s)

Davenport, Casey

Committee Members

Eastin, Matthew
Shirley, Terry

Degree Note

Thesis (M.S.)--University of North Carolina at Charlotte, 2021.

Rights Statement

This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). For additional information, see http://rightsstatements.org/page/InC/1.0/.

Rights Holder Information

Copyright is held by the author unless otherwise indicated.

Identifier

McKeown_uncc_0694N_12705

Permalink

http://hdl.handle.net/20.500.13093/etd:2118