Identification

Title

Convective episodes in the east-central United States

Abstract

Nine years of composited radar data are investigated to assess the presence of organized convective episodes in the east-central United States. In the eastern United States, the afternoon maximum in thunderstorms is ubiquitous over land. However, after removing this principal diurnal peak from the radar data, the presence and motion of organized convective systems becomes apparent in both temporally averaged fields and in the statistics of convective episodes identified by an objective algorithm. Convective echoes are diurnally maximized over the Appalachian chain, and are repeatedly observed to move toward the east. Partly as a result of this, the daily maximum in storms is delayed over the Piedmont and coastal plain relative to the Appalachian Mountains and the Atlantic coast. During the 9 yr studied, the objective algorithm identified 2128 total convective episodes (236 yr⁻¹), with several recurring behaviors. Many systems developed over the elevated terrain during the afternoon and moved eastward, often to the coastline and even offshore. In addition, numerous systems formed to the west of the Appalachian Mountains and moved into and across the eastern U.S. study domain. In particular, many nocturnal convective systems from the central United States entered the western side of the study domain, frequently arriving at the eastern mountains around the next day's afternoon maximum in storm frequency. A fraction of such well-timed systems succeeded in crossing the Appalachians and continuing across the Piedmont and coastal plain. Convective episodes were most frequent during the high-instability, low-shear months of summer, which dominate the year-round statistics. Even so, an important result is that the episodes still occurred almost exclusively in above-average vertical wind shear. Despite the overall dominance of the diurnal cycle, the data show that adequate shear in the region frequently leads to long-lived convective episodes with mesoscale organization.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7wh2q6h

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

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Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2007-11-01T00:00:00Z

Frequency of update

Quality and validity

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Conformity

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Use constraints

Copyright 2007 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.

Limitations on public access

None

Responsible organisations

Responsible party

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

Metadata on metadata

Metadata point of contact