Multiscale Analysis of a Mature Mesoscale Convective ComplexSource: Monthly Weather Review:;1993:;volume( 121 ):;issue: 001::page 103DOI: 10.1175/1520-0493(1993)121<0103:MAOAMM>2.0.CO;2Publisher: American Meteorological Society
Abstract: A multiscale analysis reveals diverse atmospheric structure and processes within a mesoscale convective complex (MCC) observed during the Oklahoma-Kansas Preliminary Regional Experiment for STORM-Central (PRE-STORM) experiment. This midlatitude system was the second in a series of four MCCs that developed and traveled along a quasi-stationary frontal zone over the central United States on 3?4 June 1985. Objectively analyzed mesoscale upper-air soundings encompassing the MCC are interpreted in tandem with more detailed dual-Doppler radar measurements that disclose the storm's internal airflow and precipitation structure. The mature MCC is found to include a variety of local environments and associated weather, ranging from tornadic thunderstorms to more linear convective bands and widespread chilling rains. A corresponding spectrum of mesoscale ver6cW-motion profiles is documented. These findings are related to previous composite-based portrayals of MCCs, as well as detailed case studies of simpler squall-type convective systems. A hallmark of this storm was its ?open-wave? precipitation pattern, in which two convective bands intersected so as to resemble a miniature developing frontal cyclone. This resemblance proves superficial, however, since 1) anticyclonic lower-tropospheric flow was observed in place of the expected cyclonic circulation near the convective apex, and 2) the accompanying wavelike lower-tropospheric temperature pattern was strongly influenced by moist processes intrinsic to the MCC (e.g., evaporative cooling), as opposed to horizontal advection about a developing vortex. The storm's intriguing organization is instead postulated to have resulted from the superposition of two preferred convective modes: one aligned with the mean vertical wind-shear vector, accompanied by marked cross-band thermal contrast and deformation through a deep layer, and another oriented perpendicular to the low-level shear, which exhibited a shallow gust front and mesoscale cold pool as found in squall-line systems. Highly three-dimensional airflow within the mature MCC and a pronounced modulation of convective instability across an embedded frontal-like zone further promoted the storm's asymmetric precipitation pattern.
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contributor author | Smull, Bradley F. | |
contributor author | Augustine, John A. | |
date accessioned | 2017-06-09T16:09:08Z | |
date available | 2017-06-09T16:09:08Z | |
date copyright | 1993/01/01 | |
date issued | 1993 | |
identifier issn | 0027-0644 | |
identifier other | ams-62102.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4202958 | |
description abstract | A multiscale analysis reveals diverse atmospheric structure and processes within a mesoscale convective complex (MCC) observed during the Oklahoma-Kansas Preliminary Regional Experiment for STORM-Central (PRE-STORM) experiment. This midlatitude system was the second in a series of four MCCs that developed and traveled along a quasi-stationary frontal zone over the central United States on 3?4 June 1985. Objectively analyzed mesoscale upper-air soundings encompassing the MCC are interpreted in tandem with more detailed dual-Doppler radar measurements that disclose the storm's internal airflow and precipitation structure. The mature MCC is found to include a variety of local environments and associated weather, ranging from tornadic thunderstorms to more linear convective bands and widespread chilling rains. A corresponding spectrum of mesoscale ver6cW-motion profiles is documented. These findings are related to previous composite-based portrayals of MCCs, as well as detailed case studies of simpler squall-type convective systems. A hallmark of this storm was its ?open-wave? precipitation pattern, in which two convective bands intersected so as to resemble a miniature developing frontal cyclone. This resemblance proves superficial, however, since 1) anticyclonic lower-tropospheric flow was observed in place of the expected cyclonic circulation near the convective apex, and 2) the accompanying wavelike lower-tropospheric temperature pattern was strongly influenced by moist processes intrinsic to the MCC (e.g., evaporative cooling), as opposed to horizontal advection about a developing vortex. The storm's intriguing organization is instead postulated to have resulted from the superposition of two preferred convective modes: one aligned with the mean vertical wind-shear vector, accompanied by marked cross-band thermal contrast and deformation through a deep layer, and another oriented perpendicular to the low-level shear, which exhibited a shallow gust front and mesoscale cold pool as found in squall-line systems. Highly three-dimensional airflow within the mature MCC and a pronounced modulation of convective instability across an embedded frontal-like zone further promoted the storm's asymmetric precipitation pattern. | |
publisher | American Meteorological Society | |
title | Multiscale Analysis of a Mature Mesoscale Convective Complex | |
type | Journal Paper | |
journal volume | 121 | |
journal issue | 1 | |
journal title | Monthly Weather Review | |
identifier doi | 10.1175/1520-0493(1993)121<0103:MAOAMM>2.0.CO;2 | |
journal fristpage | 103 | |
journal lastpage | 132 | |
tree | Monthly Weather Review:;1993:;volume( 121 ):;issue: 001 | |
contenttype | Fulltext |