Identification

Title

The Oklahoma squall line of 19 May 1977. Part I: A multiple doppler analysis of convective and stratiform structure

Abstract

On 19 May 1977, a severe squall line formed and moved through the National Severe Storms Laboratory observing network in Oklahoma, producing heavy rain, hail, strong winds, and tornadoes. The squall line is examined at two times: 1434 and 1502 CST. Doppler analysis of part of the squall line reveals four convective cells in the line, developing cells ahead of the line, a trailing precipitation region, and a convective rainband at the western edge of the system. The updrafts within the convective cells on the leading edge tilt westward in the lower levels and eastward near the tropopause. Convective updrafts and downdrafts are fed by low-level air entering the squall line from the front. Surface network analysis and gust front penetration by an instrumented aircraft indicated strong convergence along the leading edge of one of the stronger cells in the line. Horizontal, line-relative flow perpendicular to the squall line and within the trailing precipitation area is from east to west (front to back) at all levels, weakening with height. An exception to this is an area of weak (≤3 m s−1) rear inflow into the stratiform precipitation region in the midlevels. Flow parallel to the squall line is stronger, in general, than the perpendicular flow. A composite rawinsonde analysis shows ascending motion within the troposphere over most of the squall line region. A conceptual model is developed for 19 May 1977 and is compared to conceptual models of tropical squall lines and of the 22 May 1976 Oklahoma squall line.

Resource type

document

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Unique resource identifier

code

https://n2t.org/ark:/85065/d7m32xb5

codeSpace

Dataset language

eng

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Classification of spatial data and services

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geoscientificInformation

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Text

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title

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reference date

date type

publication

effective date

2016-01-01T00:00:00Z

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date type

publication

effective date

1987-10-01T00:00:00Z

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Copyright 1987 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work.

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None

Responsible organisations

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contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

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