A5086479704- Meteorological Phenomena and Simulations
- Climate variability and models
- Atmospheric aerosols and clouds
- Wind and Air Flow Studies
- Tropical and Extratropical Cyclones Research
- Atmospheric and Environmental Gas Dynamics
- Precipitation Measurement and Analysis
- Energy Load and Power Forecasting
- Spacecraft and Cryogenic Technologies
- Geophysics and Gravity Measurements
- Fish Ecology and Management Studies
- Archaeology and Natural History
- Landslides and related hazards
- Atmospheric chemistry and aerosols
- Nuclear Physics and Applications
- Remote-Sensing Image Classification
- Water Quality and Resources Studies
- Flood Risk Assessment and Management
- Astro and Planetary Science
- Plant Water Relations and Carbon Dynamics
- Aquatic Invertebrate Ecology and Behavior
- Hydrological Forecasting Using AI
- Arctic and Antarctic ice dynamics
- Land Use and Ecosystem Services
- Remote Sensing in Agriculture
University of Oklahoma
2016-2025
Cooperative Institute for Mesoscale Meteorological Studies
2015-2018
San Diego State University
2004
Abstract A GSI-based data assimilation (DA) system, including three-dimensional variational (3DVar) and ensemble Kalman filter (EnKF), is extended to the multiscale of both meso- synoptic-scale observation networks convective-scale radar reflectivity velocity observations. EnKF 3DVar are systematically compared in this context better understand impacts differences between DA techniques on analyses at multiple scales subsequent precipitation forecasts. Averaged over 10 diverse cases, 8-h...
Abstract Forecasts generated by the Center for Analysis and Prediction of Storms with 1- 4-km grid spacing using Advanced Research Weather Forecasting Model (ARW-WRF; ARW1 ARW4, respectively) 2009–11 NOAA Hazardous Testbed Spring Experiments are compared verified. Object-based measures, including average values object attributes, object-based threat score (OTS), median maximum interest (MMI) used verification. Verification was first performed against observations at scales resolvable each...
Abstract Multiscale convection-allowing precipitation forecast perturbations are examined for two forecasts and systematically over 34 out to 30-h lead time using Haar Wavelet decomposition. Two small-scale initial condition (IC) perturbation methods compared the larger-scale IC physics in an experimental ensemble. For a driven primarily by synoptic-scale baroclinic disturbance, resulted little energy on medium large scales, (LGPH) after first few hours. However, case where convection at...
Abstract Neighborhood and object-based probabilistic precipitation forecasts from a convection-allowing ensemble are verified calibrated. Calibration methods include logistic regression, one- two-parameter reliability-based calibration, cumulative distribution function (CDF)-based bias adjustment. Newly proposed for the occurrence of forecast object derived percentage members with matching object. Verification calibration single- multimodel subensembles performed to explore effect using...
Abstract The impacts of multiscale flow-dependent initial condition (IC) perturbations for storm-scale ensemble forecasts midlatitude convection are investigated using perfect-model observing system simulation experiments. Several diverse cases used to quantitatively and qualitatively understand the different IC on forecast skill. Scale dependence results is assessed by evaluating 2-h reflectivity separately from hourly accumulated mesoscale precipitation forecasts. Forecasts initialized...
Abstract The unprecedentedly high space and time resolution of infrared radiance observations from GOES‐16 Advanced Baseline Imager (ABI) present an opportunity to improve analyses short‐term forecasts rapidly evolving convective‐scale processes such as the initiation organization severe supercell thunderstorms. Such a case is used for experiments aimed at better understanding assimilation ABI all‐sky in GSI‐EnKF. Experiments assimilating channel 10 are demonstrate understand impacts...
Abstract A real-time GSI-based and ensemble-based data assimilation (DA) forecast system was implemented at the University of Oklahoma during 2015 Plains Elevated Convection Night (PECAN) experiment. Extensive experiments on configuration cycled DA both physics ensembles were conducted using retrospective cases to optimize design for nocturnal convection. The impacts radar between 1200 1300 UTC, as well frequency number cycles configuration, extend through following night. Ten-minute cycling...
Abstract Twenty-member real-time convection-allowing storm-scale ensemble forecasts with perturbations to model physics, dynamics, initial conditions (IC), and lateral boundary (LBC) during the NOAA Hazardous Weather Testbed Spring Experiment provide a unique opportunity study relative impact of different sources perturbation on diversity. In Part II this two-part study, systematic similarity/dissimilarity hourly precipitation among members from spring season 2009 are identified using...
Abstract Object-based verification of deterministic forecasts from a convection-allowing ensemble for the 2009 NOAA Hazardous Weather Testbed Spring Experiment is conducted. The average object attributes compared between and observations subensembles with different model dynamics. Forecast accuracy full dynamics also evaluated using two object-based measures: threat score (OTS) median maximum interest (MMI). objects aggregated are generally more numerous, have smaller area, circular aspect...
A prototype convection-allowing system using the Advanced Research version of Weather and Forecasting (WRF-ARW) Model employing an ensemble Kalman filter (EnKF) data assimilation technique has been developed used during spring 2016 2017 Hazardous Testbeds. This assimilates WSR-88D reflectivity radial velocity, geostationary satellite cloud water path (CWP) retrievals, available surface observations over a regional domain with 3-km horizontal resolution at 15-min intervals, initial conditions...
Abstract There has been a recent wave of attention given to atmospheric bores in order understand how they evolve and initiate maintain convection during the night. This surge is attributable data collected 2015 Plains Elevated Convection at Night (PECAN) field campaign. A salient aspect PECAN project its focus on using multiple observational platforms better convective outflow boundaries that intrude into stable boundary layer induce development bores. The intent this article threefold: 1)...
Abstract This study aims to quantify and better understand the impact of an upgrade configuration FV3 (Finite Volume cubed‐sphere) LAM (Limited Area Model) convection‐allowing ensemble on skill RF models trained cases before forecast after upgrade. Specifically, Random Forest (RF) were used produce probabilistic forecasts severe weather, significant individual hazards wind, hail, tornado for purpose day‐1 convective outlook guidance. The are different subsets available data set from spring...
Abstract Convection-allowing ensemble forecasts with perturbations to model physics, dynamics, and initial (IC) lateral boundary conditions (LBC) generated by the Center for Analysis Prediction of Storms NOAA Hazardous Weather Testbed (HWT) Spring Experiments provide a unique opportunity understand relative impact different sources perturbation on convection-allowing diversity. Such impacts are explored in this two-part study through an object-oriented hierarchical cluster analysis (HCA)...
Abstract The Advanced Baseline Imager (ABI) aboard the GOES-16 and GOES-17 satellites provides high-resolution observations of cloud structures that could be highly beneficial for convective-scale DA. However, only clear-air radiance are typically assimilated at operational centers due to a variety problems associated with cloudy data. As such, many questions remain about how best assimilate all-sky data, especially when using hybrid DA systems such as EnVar wherein nonlinear observation...
Abstract The present study introduces the online non‐linear bias correction for assimilation of all‐sky GOES‐16 Advanced Baseline Imager (ABI) channel 9 (6.9 μm) radiances in a rapidly cycled EnKF convective scale data (DA). This is first to explore use radar reflectivity as anchoring observation ABI all sky radiance assimilation. and offline nonlinear methods are compared evaluated case developing supercells over Oklahoma Texas. analysis background perform better than approach during...
The initiation of new convection at night in the Great Plains contributes to a nocturnal maximum precipitation and produces localized heavy rainfall severe weather hazards region. Although previous work has evaluated numerical model forecasts data assimilation (DA) impacts for (CI), most studies focused only on that initiates during afternoon not explicitly thunderstorms. In this study, we investigate impact assimilating situ radar observations CI event 25 June 2013 using an ensemble-based...
Abstract Multiscale ensemble-based data assimilation and forecasts were performed in real time during the Plains Elevated Convection At Night (PECAN) field experiment. A 20-member ensemble of at 4-km grid spacing was initialized daily both 1300 1900 UTC, together with a deterministic forecast 1-km UTC. The configuration GSI-based system guided by results presented Part I this two-part study. present paper describes implementation real-time extensive products that generated to support unique...
Abstract This paper presents a case study from an intensive observing period (IOP) during the Plains Elevated Convection at Night (PECAN) field experiment that was focused on bore generated by nocturnal convection. Observations PECAN IOP 25 11 July 2015 are used to evaluate performance of high-resolution Weather Research and Forecasting Model forecasts, initialized using Gridpoint Statistical Interpolation (GSI)-based ensemble Kalman filter. The focus is understanding model errors...
Abstract An object-based probabilistic (OBPROB) forecasting framework is developed and applied, together with a more traditional neighborhood-based framework, to convection-permitting ensemble forecasts produced by the University of Oklahoma (OU) Multiscale data Assimilation Predictability (MAP) laboratory during 2017 2018 NOAA Hazardous Weather Testbed Spring Forecasting Experiments. Case studies from are used for parameter tuning demonstration methodology, while systematically verified....
Abstract A case study characterized by Arctic cyclogenesis following a tropopause polar vortex (TPV)-induced Rossby wave initiation event is used to better understand how well existing observations constrain analyses of processes influencing cyclone predictive skill. Complementary techniques observation system experiments (OSE) and ensemble sensitivity analysis (ESA) are investigate the impacts networks on predictions for this case. The ESA reveals that large-scale structure correlated with...
Abstract Four case studies from the Plains Elevated Convection at Night (PECAN) field experiment are used to investigate impacts of horizontal and vertical resolution, mixing parameterization, on predictions bore structure upscale bores their mesoscale environment. The reduction environmental convective inhibition (CIN) created by is particularly emphasized. Simulations run with grid spacings ranging 250 1000 m, as well 50 m for one study, different level configurations, closure models...
Abstract The Great Arctic Cyclone 2012 (AC12) is used to understand the role of initial condition errors in predictability at 2–3‐day forecast range a high‐impact summer (AC). Ensemble sensitivity analysis (ESA) first performed identify potentially sensitive regions cyclone evolution using an ensemble baseline with conventional situ observations assimilated. A pseudo‐observation method then introduced investigate impacts hypothetical these but unobserved regions. In experiments assimilated,...
Abstract The impact of assimilating in situ temperature, moisture and wind observations from a WindBorne Systems balloon, with long duration adjustable ballast, is evaluated using case study the 2022 THINICE field campaign. A selected wherein balloon directly sampled jet streak associated tropopause polar vortex (TPV). observed TPV merged another at same time as downstream Arctic cyclone (AC) redeveloped eastward. used to better understand role evolution AC. assimilation improves forecast...
Abstract The THINICE field campaign, based from Svalbard in August 2022, provided unique observations of summertime Arctic cyclones, their coupling with cloud cover, and interactions tropopause polar vortices sea ice conditions. was motivated by the need to advance our understanding these processes improve coupled models used forecast weather ice, as well long-term projections climate change Arctic. Two research aircraft were deployed complementary instrumentation. Safire ATR42 aircraft,...
Abstract This study evaluates simulated radiance forecasts from a series of controlled experiments consisting FV3‐LAM with different configurations model physics and vertical resolution. The were produced during the 2020 Hazardous Weather Testbed Spring Forecasting Experiments on same forecast cases. evaluation includes grid‐point, neighborhood‐based object‐based verification. include that identical except for (EMC‐LAM vs. EMC‐LAMx), resolution (EMC‐LAMx NSSL‐LAM), or combined initial...