On the Movements of Convective Storms, with Emphasis on Size Discrimination in Relation to Water-Budget Requirements

Newton, Chester W.; Fankhauser, J. C.

doi:10.1175/1520-0450(1964)003<0651:otmocs>2.0.co;2

Cited by 56 publications

(39 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The counteracting effects of upwind development and downwind advection constitute the discrete propagation of convective cells, similar to squall-line behavior studied by Newton and Fankhauser (1964). In the absence of outside influences, the result would be a principal rain-band that remains sustained and quasi-stationary relative to the storm center for extended periods of time, which is consistent with observations in previous studies.…”

Section: B Growth and Sustenance Of The Principal Rainbandsupporting

confidence: 87%

Convective-Scale Downdrafts in the Principal Rainband of Hurricane Katrina (2005)

Didlake

Houze

2009

Monthly Weather Review

View full text Add to dashboard Cite

Airborne Doppler radar data collected during the Hurricane Rainband and Intensity Change Experiment (RAINEX) document downdrafts in the principal rainband of Hurricane Katrina (2005). Inner-edge downdrafts (IEDs) originating at 6-8-km altitude created a sharp reflectivity gradient along the inner boundary of the rainband. Low-level downdrafts (LLDs) evidently driven by precipitation drag originated at 2-4 km within the heavy rain cells of each convective element. The IED and LLD were spatially separated by but closely associated with the updrafts within the rainband. The IED was forced aloft by pressure perturbations formed in response to the adjacent buoyant updrafts. Once descending, the air attained negative buoyancy via evaporative cooling from the rainband precipitation. A convective-scale tangential wind maximum tended to occur in the radial inflow at lower levels in association with the IED, which enhanced the inward flux of angular momentum at lower levels. Convergence at the base of the downdrafts on the upwind end of the principal rainband contributed to the principal rainband growing in length. New updraft elements triggered by this convergence led to the formation of new IED and LLD pockets, which were subsequently advected downwind around the storm by the vortex winds while additional new cells continued to form on the upwind end of the band. These processes sustained the principal rainband and helped to make it effectively stationary relative to the storm center, thus maintaining its impact on the hurricane dynamics over an extended period.

show abstract

Section: B Growth and Sustenance Of The Principal Rainbandsupporting

confidence: 87%

Convective-Scale Downdrafts in the Principal Rainband of Hurricane Katrina (2005)

Didlake

Houze

2009

Monthly Weather Review

View full text Add to dashboard Cite

show abstract

“…Byers and Braham (1949) noted that most storm elements within squall lines have some component of motion to the left 2 of the system's line-normal motion. In turn, Newton and Fankhauser (1964) were perhaps the first to point out that this might entail a significant along-line transport of hydrometeors, with the consequent development of a stratified line-parallel anvil cloud mass in which new storms were unlikely to develop. They also noted that, with respect to storm motion, the line's right-hand side was the site of most rapid growth for new and young convective cells.…”

Section: Introductionmentioning

confidence: 99%

Simulated Convective Lines with Parallel Stratiform Precipitation. Part I: An Archetype for Convection in Along-Line Shear

Parker

2007

Journal of the Atmospheric Sciences

View full text Add to dashboard Cite

This article, the first of two describing convective lines with parallel stratiform (PS) precipitation, addresses the basic kinematic and precipitation features of these systems. The PS mode appears to be the preferred organizational structure in environments with line-parallel vertical wind shear. This archetype for long-lived convective systems has received relatively little attention to date, and yet it is frequently implicated in flash flooding because it entails both the along-line movement of hydrometeors and back-building convective development. As a reality check, this paper presents conventional observations of the wind and reflectivity fields associated with an archetypal PS system from 2 May 1997. Thereafter, analyses of idealized numerical simulations serve as the basis for a more detailed investigation of PS systems' internal structures and processes.The observations and simulations suggest several unique aspects of the PS structure. The environment's vertically sheared 3D wind profile helps to explain PS systems' tendency to back-build, develop line-parallel precipitation, and evolve asymmetrically. Along-line flow within the system cold pool entails back-building on both the mesoscale and the convective scale. As well, along-line flow in the upper troposphere within the system entails along-line hydrometeor transports, especially in the leading and trailing anvils. These behaviors lead to the archetypal PS structure.Along-line hydrometeor advection means that much of the system's precipitation falls very near its outflow boundary, and that the convective cells can seed other updrafts farther down the line. As a result, PS systems in line-parallel shear can intensify their cold pools quite rapidly. As well, in time the PS structure is characterized by diminished upper-tropospheric along-line flow within its axis. These factors may hasten transition toward a predominantly rearward-sloped updraft and the production of trailing precipitation. Even in the absence of Coriolis accelerations, this evolutionary pathway leads to highly asymmetric structures, such as are commonly observed in midlatitudes.The present introductory exposition of PS systems in deep tropospheric line-parallel wind shear sets the stage for a detailed investigation of their dynamics and sensitivities in a companion article.

show abstract

“…The windstorm extended more 45 than 1000 km (620 mi) from the Ohio River southward to the Gulf Coast and was responsible 46 for several deaths, at least 30 injuries, and millions of dollars in damage, mainly to trees and 47 power lines. In addition, although the line of storms produced straight-line wind damage that 75 1 Magnitude of the mean low to mid-tropospheric flow, VMean, was calculated in the following manner: , where V850, V700, V500, and V300 refer to the magnitude of representative, raob-observed 850, 700, 500, and 300 hPa wind speeds, respectively, following Newton and Fankhauser (1964) and Corfidi et al (1996). While substantial, this 73 speed was below that of the mean, low-to mid-tropospheric flow (about 21.6 m s -1 or 42 kts; 74 Figure 1) 1 .…”

mentioning

confidence: 99%

A Proposed Revision to the Definition of “Derecho”

Corfidi

Coniglio

Cohen

et al. 2016

Bulletin of the American Meteorological Society

View full text Add to dashboard Cite

The word “derecho” was first used by Gustavus Hinrichs in 1888 to distinguish the widespread damaging windstorms that occurred on occasion over the mid–Mississippi Valley region of the United States from damaging winds associated with tornadoes. The term soon fell into disuse, however, and did not appear in the literature until Robert Johns and William Hirt resurrected it in the mid-1980s. While the present definition of derecho served well during the early years of the term’s reintroduction to the meteorological community, it has several shortcomings. These have become more apparent in recent years as various studies shed light on the physical processes responsible for the production of widespread damaging winds. In particular, the current definition’s emphasis on the coverage of storm reports at the expense of identifying the convective structures and physical processes deemed responsible for the reports has led to the term being applied to wind events beyond those for which it originally was intended. The revised definition of a derecho proposed herein is intended to focus more specifically on those types of windstorms that are the most damaging and potentially life threatening because of their intensity, sustenance, and degree of organization. The proposal is not intended to be final or all encompassing, but rather an initial step toward ultimately realizing a more complete physically based taxonomy that also addresses other forms of damaging-wind-producing convective systems.

show abstract

On the Movements of Convective Storms, with Emphasis on Size Discrimination in Relation to Water-Budget Requirements

Cited by 56 publications

References 0 publications

Convective-Scale Downdrafts in the Principal Rainband of Hurricane Katrina (2005)

Convective-Scale Downdrafts in the Principal Rainband of Hurricane Katrina (2005)

Simulated Convective Lines with Parallel Stratiform Precipitation. Part I: An Archetype for Convection in Along-Line Shear

A Proposed Revision to the Definition of “Derecho”

Contact Info

Product

Resources

About