On the predictability of mesoscale convective systems

Three-dimensional simulations

Matthew S. Wandishin, David Jonathan Stensrud, Steven L. Mullen, Louis J. Wicker

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Mesoscale convective systems (MCSs) are a dominant climatological feature of the central United States and are responsible for a substantial fraction of warm-season rainfall. Yet very little is known about the predictability of MCSs. To help address this situation, a previous paper by the authors examined a series of ensemble MCS simulations using a two-dimensional version of a storm-scale (Δx 5 1 km) model. Ensemble member perturbations in the preconvective environment, namely, wind speed, relative humidity, and convective instability, are based on current 24-h forecast errors from the North American Model (NAM). That work is now extended using a full three-dimensional model. Results from the three-dimensional simulations of the present study resemble those found in two dimensions. The model successfully produces anMCSwithin 100 km of the location of the control run in around 70% of the ensemble runs using perturbations to the preconvective environment consistent with 24-h forecast errors, while reducing the preconvective environment uncertainty to the level of current analysis errors improves the success rate to nearly 85%. This magnitude of improvement in forecasts of environmental conditions would represent a radical advance in numerical weather prediction. The maximum updraft and surface wind forecast uncertainties are of similar magnitude to their two-dimensional counterparts. However, unlike the two-dimensional simulations, in three dimensions, the improvement in the forecast uncertainty of storm features requires the reduction of preconvective environmental uncertainty for all perturbed variables. The MCSs in many of the runs resemble bow echoes, but surface winds associated with these solutions, and the perturbation profiles that produce them, are nearly indistinguishable from the nonbowing solutions, making any conclusions about the bowlike systems difficult.

Original languageEnglish (US)
Pages (from-to)863-885
Number of pages23
JournalMonthly Weather Review
Volume138
Issue number3
DOIs
StatePublished - Mar 1 2010

Fingerprint

convective system
simulation
perturbation
surface wind
updraft
error analysis
relative humidity
wind velocity
environmental conditions
forecast
weather
rainfall
prediction

All Science Journal Classification (ASJC) codes

  • Atmospheric Science

Cite this

Wandishin, Matthew S. ; Stensrud, David Jonathan ; Mullen, Steven L. ; Wicker, Louis J. / On the predictability of mesoscale convective systems : Three-dimensional simulations. In: Monthly Weather Review. 2010 ; Vol. 138, No. 3. pp. 863-885.
@article{a4302a78301d455e97cd014a4532bcf7,
title = "On the predictability of mesoscale convective systems: Three-dimensional simulations",
abstract = "Mesoscale convective systems (MCSs) are a dominant climatological feature of the central United States and are responsible for a substantial fraction of warm-season rainfall. Yet very little is known about the predictability of MCSs. To help address this situation, a previous paper by the authors examined a series of ensemble MCS simulations using a two-dimensional version of a storm-scale (Δx 5 1 km) model. Ensemble member perturbations in the preconvective environment, namely, wind speed, relative humidity, and convective instability, are based on current 24-h forecast errors from the North American Model (NAM). That work is now extended using a full three-dimensional model. Results from the three-dimensional simulations of the present study resemble those found in two dimensions. The model successfully produces anMCSwithin 100 km of the location of the control run in around 70{\%} of the ensemble runs using perturbations to the preconvective environment consistent with 24-h forecast errors, while reducing the preconvective environment uncertainty to the level of current analysis errors improves the success rate to nearly 85{\%}. This magnitude of improvement in forecasts of environmental conditions would represent a radical advance in numerical weather prediction. The maximum updraft and surface wind forecast uncertainties are of similar magnitude to their two-dimensional counterparts. However, unlike the two-dimensional simulations, in three dimensions, the improvement in the forecast uncertainty of storm features requires the reduction of preconvective environmental uncertainty for all perturbed variables. The MCSs in many of the runs resemble bow echoes, but surface winds associated with these solutions, and the perturbation profiles that produce them, are nearly indistinguishable from the nonbowing solutions, making any conclusions about the bowlike systems difficult.",
author = "Wandishin, {Matthew S.} and Stensrud, {David Jonathan} and Mullen, {Steven L.} and Wicker, {Louis J.}",
year = "2010",
month = "3",
day = "1",
doi = "10.1175/2009MWR2961.1",
language = "English (US)",
volume = "138",
pages = "863--885",
journal = "Monthly Weather Review",
issn = "0027-0644",
publisher = "American Meteorological Society",
number = "3",

}

On the predictability of mesoscale convective systems : Three-dimensional simulations. / Wandishin, Matthew S.; Stensrud, David Jonathan; Mullen, Steven L.; Wicker, Louis J.

In: Monthly Weather Review, Vol. 138, No. 3, 01.03.2010, p. 863-885.

Research output: Contribution to journalArticle

TY - JOUR

T1 - On the predictability of mesoscale convective systems

T2 - Three-dimensional simulations

AU - Wandishin, Matthew S.

AU - Stensrud, David Jonathan

AU - Mullen, Steven L.

AU - Wicker, Louis J.

PY - 2010/3/1

Y1 - 2010/3/1

N2 - Mesoscale convective systems (MCSs) are a dominant climatological feature of the central United States and are responsible for a substantial fraction of warm-season rainfall. Yet very little is known about the predictability of MCSs. To help address this situation, a previous paper by the authors examined a series of ensemble MCS simulations using a two-dimensional version of a storm-scale (Δx 5 1 km) model. Ensemble member perturbations in the preconvective environment, namely, wind speed, relative humidity, and convective instability, are based on current 24-h forecast errors from the North American Model (NAM). That work is now extended using a full three-dimensional model. Results from the three-dimensional simulations of the present study resemble those found in two dimensions. The model successfully produces anMCSwithin 100 km of the location of the control run in around 70% of the ensemble runs using perturbations to the preconvective environment consistent with 24-h forecast errors, while reducing the preconvective environment uncertainty to the level of current analysis errors improves the success rate to nearly 85%. This magnitude of improvement in forecasts of environmental conditions would represent a radical advance in numerical weather prediction. The maximum updraft and surface wind forecast uncertainties are of similar magnitude to their two-dimensional counterparts. However, unlike the two-dimensional simulations, in three dimensions, the improvement in the forecast uncertainty of storm features requires the reduction of preconvective environmental uncertainty for all perturbed variables. The MCSs in many of the runs resemble bow echoes, but surface winds associated with these solutions, and the perturbation profiles that produce them, are nearly indistinguishable from the nonbowing solutions, making any conclusions about the bowlike systems difficult.

AB - Mesoscale convective systems (MCSs) are a dominant climatological feature of the central United States and are responsible for a substantial fraction of warm-season rainfall. Yet very little is known about the predictability of MCSs. To help address this situation, a previous paper by the authors examined a series of ensemble MCS simulations using a two-dimensional version of a storm-scale (Δx 5 1 km) model. Ensemble member perturbations in the preconvective environment, namely, wind speed, relative humidity, and convective instability, are based on current 24-h forecast errors from the North American Model (NAM). That work is now extended using a full three-dimensional model. Results from the three-dimensional simulations of the present study resemble those found in two dimensions. The model successfully produces anMCSwithin 100 km of the location of the control run in around 70% of the ensemble runs using perturbations to the preconvective environment consistent with 24-h forecast errors, while reducing the preconvective environment uncertainty to the level of current analysis errors improves the success rate to nearly 85%. This magnitude of improvement in forecasts of environmental conditions would represent a radical advance in numerical weather prediction. The maximum updraft and surface wind forecast uncertainties are of similar magnitude to their two-dimensional counterparts. However, unlike the two-dimensional simulations, in three dimensions, the improvement in the forecast uncertainty of storm features requires the reduction of preconvective environmental uncertainty for all perturbed variables. The MCSs in many of the runs resemble bow echoes, but surface winds associated with these solutions, and the perturbation profiles that produce them, are nearly indistinguishable from the nonbowing solutions, making any conclusions about the bowlike systems difficult.

UR - http://www.scopus.com/inward/record.url?scp=77953183466&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77953183466&partnerID=8YFLogxK

U2 - 10.1175/2009MWR2961.1

DO - 10.1175/2009MWR2961.1

M3 - Article

VL - 138

SP - 863

EP - 885

JO - Monthly Weather Review

JF - Monthly Weather Review

SN - 0027-0644

IS - 3

ER -