About

Matthew Parker is a Professor at NC State University within the Department of Marine, Earth, and Atmospheric Sciences. His contact information includes a phone number (919-513-4367) and email (mdparker@ncsu.edu). The page does not provide specific details about his research focus, background, or key contributions.

Research topics

• Meteorology
• Environmental science
• Geology
• Climatology
• Atmospheric sciences
• Geography
• Physics
• Demography

Selected publications

• Variability in High-Shear, Low-CAPE QLCS Environments in the Southeastern U.S.

  Weather and Forecasting · 2026-04-13

  articleSenior author

  Abstract High-shear, low-CAPE (HSLC) quasi-linear convective systems (QLCSs) in the Southeastern United States pose a challenge to operational forecasters. Prior studies have investigated bulk environmental ingredients associated with the severe weather produced by these systems; however, there is spatial and temporal variability in HSLC severe weather from QLCSs that has yet to be explained. This study sought to improve the conceptual model for HSLC QLCSs by characterizing heterogeneities in their environments. In pursuit of this goal, QLCS-relative analyses that incorporate hourly data spanning the full duration of 79 HSLC QLCS events occurring across the Southeastern U.S. were created using archived operational High-Resolution Rapid Refresh (HRRR) model data. ‘All case’ composites reveal that HSLC environments are not uniformly “low-CAPE”, and HSLC QLCSs may be partially fed by elevated “most unstable” parcels. Additionally, comparisons of different QLCS regimes show greater bulk shear magnitudes along the poleward portions of the QLCS convective lines during tornadic hours, which may explain the poleward bias of QLCS tornado reports noted by prior studies. A strong correlation was also identified between low-level nocturnal stabilization and the enhancement of both the low-level jet and low-level vertical wind shear. These enhancements could account for the prevalence of nocturnal tornadoes produced by these systems. Finally, the potential response to diabatic heating (i.e., low-level flow enhancements) may contribute to increased bulk shear magnitudes during the mature phase of these systems, which could help address the noted time lag between system formation and the occurrence of the first tornado reports.

  PublisherDOI

• Supercell Environments Using GridRad-Severe and the HRRR: Addressing Discrepancies between Prior Tornado Datasets

  Weather and Forecasting · 2025-05-30

  articleOpen access

  Abstract Storm-relative helicity (SRH) is an important ingredient in supercell development, as well as mesocyclone intensity, and is linked to tornadogenesis and tornado potential. Derived from the storm-relative wind profile, SRH is composed of both the vertical wind shear and storm-relative flow. Recent studies have come to conflicting findings regarding whether shallower or deeper layers of SRH have more skill in tornado forecasting. Possible causes of this discrepancy include the use of observed versus model-based proximity soundings, as well as whether the storm-relative wind profile is determined via observed versus estimated storm motions. This study uses a new dataset of objectively identified supercells, with observed storm motions, paired with high-resolution model analyses to address the discrepancies among prior studies. Unlike in previous model-based tornado environmental datasets, the present approach reveals substantive differences in storm-relative flow, vertical wind shear, and SRH within the low- to midlevels between nontornadic and tornadic supercells. Using observed storm motions for storm-relative variables further magnifies differences in the low- to midlevel storm-relative winds between nontornadic and tornadic supercells, ultimately leading to deeper layers of SRH having more forecast skill than near-ground SRH. Thus, the combination of a higher-resolution model analysis, which better represents the near-storm environment, with observed storm motions appears to explain why many past tornado climatologies using model-based environmental analyses have failed to find significant differences in the storm-relative wind profile. These results help bridge the gap between previous studies that employed coarser model-based analyses and those that aggregated observed soundings from field projects.

  PublisherOA PDFDOI

• Properties of Cold Pools from PERiLS 2022–23

  Monthly Weather Review · 2025-07-25

  article

  Abstract Cold pools play a range of important roles in quasi-linear convective systems (QLCSs), including maintenance via the development of new convective cells as well as baroclinic generation of horizontal vorticity. Although a number of QLCS cold pools have been characterized in the literature using one or a few sensors, their variability (both internally and across a range of environments) has still not been widely studied. This gap in knowledge extends particularly to high-shear low-CAPE (HSLC) convective environments common to the cool season in the southeastern United States, where the Propagation, Evolution, and Rotation in Linear Storms (PERiLS) field campaign was focused. PERiLS specifically targeted environmental and storm-scale processes in QLCSs, including their cold pools. Our analysis focuses on the heterogeneity and temporal variability of cold pools across short time and spatial scales using numerous surface and sounding observations across five PERiLS QLCSs. The PERiLS cold pools are generally weaker than those previously studied in warm-season, midlatitude QLCSs, likely due to the lower CAPE and higher relative humidity values common to HSLC environments during PERiLS. Nevertheless, the distributions of most PERiLS cold pool variables at least partially overlap with those of previously studied QLCSs. The median PERiLS measurement reveals a cold pool that is ≈2.5 km deep, having a surface temperature decrease of ≈−6°C, and a peak outflow wind gust of ≈13 m s −1 . In the spirit of a “cold pool audit,” we present the internal and case-to-case variability of these particularly well-observed QLCSs. Significance Statement Evaporatively cooled air masses (“cold pools”) are created by quasi-linear convective systems (“QLCSs,” also called “squall lines”), and they in turn play important roles in the maintenance and structures of QLCSs. There have been relatively few direct measurements of cold pool variability, especially for the frequently severe QLCSs occurring during the cool season in the southeastern United States. Numerous surface and upper-air measurements from the recent Propagation, Evolution, and Rotation in Linear Storms (“PERiLS”) field experiment are used to document Southeastern QLCS cold pools. The PERiLS cold pools were surprisingly similar to, albeit somewhat weaker than, those found in prior studies of warm-season QLCSs in other regions.

  PublisherDOI

• Characteristics of Tornadic and Nontornadic QLCS Mesovortices Observed Using Radar and Pod Data from PERiLS

  Weather and Forecasting · 2025-07-29

  article

  Abstract The challenges associated with nowcasting quasi-linear convective system (QLCS) tornadoes are well documented. One key challenge is that QLCS tornadoes typically develop within mesovortices (MVs), but not all MVs are tornadic. This study used radar and in situ Pod data collected during the Propagation, Evolution, and Rotation in Linear Storms (PERiLS) field campaign to examine the characteristics that differentiate tornadic (TOR), wind-damaging (WD), and nondamaging (ND) MVs at various stages in their lifetimes and to investigate the low-level structure of QLCS MVs. Thirty-one QLCS MVs were manually identified and cataloged using the lowest elevation scans of the nearest WSR-88D and C-band on Wheels (COW) radars during the two years of PERiLS. TOR MVs, over their entire lifetimes, had stronger rotational velocities (Vrots), smaller diameters, and slightly longer lifetimes compared to WD and ND MVs. When MVs were analyzed during their pretornadic, predamaging, and prewarning phases (prephases), TOR and WD MVs had similar Vrots; however, TOR MVs typically had smaller diameters and contracted leading up to tornadogenesis, which could benefit nowcasters. In five cases, MVs were observed at the lowest WSR-88D elevation scans but were not visible in the COW data; the MV structure at different elevation angles for one case is presented. Eight Pods showed evidence of MV intercepts, demonstrated most notably by decreases in pressure. COW data, along with relatively weak wind speeds measured by Pods that collected data on MVs, suggest that vertical variations in low-level MV structure and strength can exist, which may not be adequately captured by the WSR-88D network.

  PublisherDOI

• Long-Term Trends in Convective Weather and Environments in the Southeastern United States

  2025-08-08

  articleOpen accessSenior author

  Long-term trends in convective environments suggest a decline in environmental vertical wind shear, however instability (i.e. CAPE) is projected to increase. This may be particularly important in the Southeastern U.S. cool season, where instability is characteristically limited but vertical shear is generally very large and can still be favorable for convection given an overall decline. An increase in cool-season instability could result in more frequent hazardous convective weather (HCW) as well as a change in storm mode, resulting in a different distribution of hazards that can impact a new subset of the population that would not currently expect HCW. We exploit 10-year present and future global time-slice MPAS simulations from Michaelis et. al (2019) as a baseline for studying the change in frequency, mode, and intensity of HCW in the Southeastern U.S. The MPAS model uses a global-scale, 60 km grid which is reduced to a high resolution 15 km grid over the Northern Hemisphere to incorporate the effects of large-scale processes. We identify convective windows using the MPAS convective precipitation, CAPE, and 0-6 km vertical shear parameters at 6-hour output intervals. First, we address whether the location, frequency, and character of these windows is changing over time in the non-convection-allowing MPAS simulations. Subsequently, we use a downscaling approach to study whether the mode and severity of resolved convection will change within the convective environments extracted from MPAS.

  PublisherDOI

• Interactions between Supercells in Multistorm Simulations

  Monthly Weather Review · 2025-08-13

  article

  Abstract Tornadic and nontornadic supercells have been observed in close proximity to one another, despite coexisting in a similar environment. One possibility is that localized heterogeneity in the environment produces changes in tornadogenesis likelihood. Such environmental heterogeneity may be induced by supercell thunderstorms themselves. This study investigates whether adjacent supercells influence one another, particularly focusing on influences to tornadogenesis likelihood. The study uses idealized numerical simulations of isolated supercells to identify how supercells introduce heterogeneity into their surrounding environment. Then, a series of multistorm simulations are used to investigate how storm-induced heterogeneity affects neighboring supercells and tornadogenesis likelihood. The most influential forms of storm-induced heterogeneity are found to be residual cold pools in the wake of supercells, dry air descending from aloft on the upshear flank of supercells, and left-moving splits from supercells. Residual cold pools and descending dry air weakened neighboring supercells and decreased the likelihood of tornadogenesis. Mergers with left-moving splits momentarily strengthened supercells and increased tornadogenesis likelihood before other storm-induced heterogeneity weakened these supercells. In the most hostile examples of storm-induced heterogeneity, neighboring supercells weakened to the point of dissipation. In the most favorable examples of storm-induced heterogeneity, low-level supercell updrafts nearly doubled their vertical velocity. These findings may explain why tornado production can vary between supercells coexisting in a similar environment. Significance Statement Supercells are intense thunderstorms that can produce tornadoes. While research has excelled in identifying environmental ingredients favorable for tornadoes, multiple supercells within the same general environment can vary in tornado production. This study investigates whether supercell thunderstorms themselves can influence neighboring storms and their likelihood of producing a tornado. It was found that supercells can modify the surrounding environment, creating regions where neighboring storms can have increased or decreased likelihood of producing a tornado. These results may be helpful for forecasting tornadoes during a multisupercell event.

  PublisherDOI

• On Discrete Convective Updrafts and Tornadoes in Quasi-Linear Convective Systems

  Weather and Forecasting · 2025-05-13

  articleOpen access

  Abstract This research attempts to use operational radar and satellite products to identify potential locations of quasi-linear convective system (QLCS) tornadogenesis, which can be difficult to predict. It is hypothesized that deep, discrete updrafts indicate portions of the QLCS capable of producing tornadoes, whereas shallower convection indicates more benign portions of the QLCS. To address this hypothesis, storm reports and storm surveys on 30–31 March 2022, during the second intensive observing period of the 2022 Propagation, Evolution, and Rotation in Linear Storms (PERiLS) field campaign, are used to identify locations of tornadoes within the QLCS. These tornado locations are then compared to representations of upper-tropospheric updrafts, namely, overshooting tops (OTs), which are identified with an algorithm using 1-min-resolution mesoscale sector data from GOES-16 Advanced Baseline Imager infrared brightness temperatures, and radar reflectivity cores aloft, identified with Multi-Radar Multi-Sensor (MRMS) 3D mosaic reflectivity products. Only a fraction (less than 30%) of tornadoes within the QLCS are associated with OTs, though over 85% of tornadoes are located near convective cores as indicated by cores of enhanced reflectivity at 9 km MSL. A numerical simulation of the event is also conducted using the Weather Research and Forecasting (WRF) Model which shows a strong relationship between simulated updraft intensity and reflectivity aloft. Given this apparent support of the hypothesis, the identification of updraft signatures within MRMS and high-resolution geostationary satellite data may ultimately help improve the identification of regions within QLCSs most likely to result in tornadoes.

  PublisherOA PDFDOI

• Variability in supercell motion

  2025-08-08

  preprintOpen access1st authorCorresponding

  Recent studies (e.g., Bunkers 2018, Coniglio and Parker 2020) suggest that tornado-producing supercells often have motion vectors that deviate farther from the mean wind (being slower and more rightward) than non-tornadic supercells. This enhanced deviant motion could be either a cause of tornado production (as such storms would usually experience substantial increases in storm-relative helicity) or an effect of tornado production (due to internal storm dynamics that haven’t been fully explained). Cause and effect are rather elusive for real-world supercells, both due to observational limitations and because storms move through horizontally heterogeneous environments. Here we isolate variability in supercell motion by studying a set of three existing ensembles of idealized supercell simulations (15 tornadic supercells from Coffer et al. 2017, 12 non-tornadic supercells from Coffer et al. 2017, and 25 tornadic supercells from Markowski 2020). For each ensemble, all members were simulated using identical mean wind profiles, but with added random noise to produce spread. Within each ensemble, the x- and y-components of storm motion both vary over ranges of 7-8 m/s. Among other questions, in this study we address the following. How large are the accompanying variations in storm-relative helicity? Are there lead or lag correlations between tornado times and changes in motion vectors in the simulations? And, are the changes in motion vectors merely stochastic or can they be anticipated from observable processes?

  PublisherDOI

• Supercell Tornadogenesis: Recent Progress in Our State of Understanding

  Bulletin of the American Meteorological Society · 2024-04-18 · 13 citations

  articleOpen access

  Abstract Over the last decade, supercell simulations and observations with ever-increasing resolution have provided new insights into the vortex-scale processes of tornado formation. This article incorporates these and other recent findings into the existing three-step model by adding an additional fourth stage. The goal is to provide an updated and clear picture of the physical processes occurring during tornadogenesis. Specifically, we emphasize the importance of the low-level wind shear and mesocyclone for tornado potential, the organization and interaction of relatively small-scale pretornadic vertical vorticity maxima, and the transition to a tornado-characteristic flow. Based on these insights, guiding research questions are formulated for the decade ahead. Significance Statement This article provides a nontechnical overview of how tornadoes form. Sequentially, the most important processes include the initial creation of rotating updrafts, the development of disorganized patches of rotation at the surface, the organization of these patches into a more defined, symmetric vortex, and the final transition into a fully developed tornado in which air turns abruptly upward very near the surface. Based on this proposed conceptual model, guiding research questions are formulated for the decade ahead.

  PublisherOA PDFDOI

• Numerical Models: Convective Storm Modeling

  Elsevier eBooks · 2024-01-01

  book-chapter1st authorCorresponding
  PublisherDOI

Recent grants

• CAREER: Integrated Studies of Recurring, Non-Traditional Mesoscale Convective Systems

  NSF · $492k · 2005–2011

• Mechanisms Controlling the Probability of Tornadogenesis in Supercell Thunderstorms

  NSF · $587k · 2018–2023

• Fundamental Lower Tropospheric Processes in Observed and Simulated Supercells

  NSF · $485k · 2012–2017

• VORTEX2: Mobile Upsonde Measurements and Studies of Lower Tropospheric Processes

  NSF · $475k · 2008–2013

• Collaborative Research: Measurement and Analysis of Nocturnal Mesoscale Convective Systems and Their Stable Boundary Layer Environment During PECAN

  NSF · $293k · 2014–2021

Frequent coauthors

• Brice E. Coffer

  North Carolina State University

  13 shared

• Andrew J. Taberner

  University of Auckland

  11 shared

• Poul M. F. Nielsen

  10 shared

• Martyn P. Nash

  9 shared

• Richard H. Johnson

  8 shared

• Keith D. Sherburn

  NOAA National Weather Service

  7 shared

• Conrad L. Ziegler

  University of Oklahoma

  6 shared

• Michael C. Coniglio

  NOAA National Severe Storms Laboratory

  6 shared

Education

• Ph.D., Atmospheric Science

  Colorado State University

  2002

• M.S., Atmospheric Science

  Colorado State University

  1999

• B.S., Geography and Meteorology

  Valparaiso University

  1996