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RISMarkov Chain Modeling of Sequences of Lagged NWP Ensemble Probability Forecasts: An Exploration of Model Properties and Decision Support Applications
Publisher: American Meteorological Society
Abstract: It is shown that sequences of lagged ensemble-derived probability forecasts can be treated as being realizations of a discrete, finite-step Markov chain. A reforecast ensemble dataset is used to explore this idea for the ...
Diagnosing the Relative Impact of “Sneaks,” “Phantoms,” and Volatility in Sequences of Lagged Ensemble Probability Forecasts with a Simple Dynamic Decision Model
Publisher: American Meteorological Society
Abstract: Monte Carlo simulation of sequences of lagged ensemble probability forecasts is undertaken using Markov transition law estimated from a reforecast ensemble. A simple three-state, three-action dynamic decision model is then ...
Surface Cyclolysis in the North Pacific Ocean. Part III: Composite Local Energetics of Tropospheric-Deep Cyclone Decay Associated with Rapid Surface Cyclolysis
Publisher: American Meteorological Society
Abstract: Two regional local energetics composites of tropospheric-deep cyclone decay were constructed based upon 49 cyclones in the Gulf of Alaska region and 18 cyclones in the Bering Sea region whose decay was marked by rapid ...
Ensemble Prediction of Atmospheric Refractivity Conditions for EM Propagation
Publisher: American Meteorological Society
Abstract: n ensemble forecast system has been developed at the Naval Research Laboratory to improve the analyses and forecasts of atmospheric refractivity for electromagnetic (EM) propagation with the intention of accounting for ...
A Local Formulation of the Ensemble Transform (ET) Analysis Perturbation Scheme
Publisher: American Meteorological Society
Abstract: Following ideas from the local ensemble transform Kalman filter, a local formulation of the ensemble transform (ET) analysis perturbation scheme is developed by partitioning the numerical weather prediction model domain ...
Impact of Stochastic Convection on the Ensemble Transform
Publisher: American Meteorological Society
Abstract: The impact of stochastic convection on ensembles produced using the ensemble transform (ET) initial perturbation scheme is examined. This note compares the behavior of ensemble forecasts based only on initial ET perturbations ...
Evaluation of the Ensemble Transform Analysis Perturbation Scheme at NRL
Publisher: American Meteorological Society
Abstract: The ensemble transform (ET) scheme changes forecast perturbations into analysis perturbations whose amplitudes and directions are consistent with a user-provided estimate of analysis error covariance. A practical demonstration ...
Inducing Tropical Cyclones to Undergo Brownian Motion: A Comparison between Itô and Stratonovich in a Numerical Weather Prediction Model
Publisher: American Meteorological Society
Abstract: tochastic parameterization has become commonplace in numerical weather prediction (NWP) models used for probabilistic prediction. Here a specific stochastic parameterization will be related to the theory of stochastic ...
Time-Expanded Sampling for Ensemble-Based Data Assimilation Applied to Conventional and Satellite Observations
Publisher: American Meteorological Society
Abstract: he time-expanded sampling (TES) method, designed to improve the effectiveness and efficiency of ensemble-based data assimilation and subsequent forecast with reduced ensemble size, is tested with conventional and satellite ...
Comparison of Hybrid Ensemble/4DVar and 4DVar within the NAVDAS-AR Data Assimilation Framework
Publisher: American Meteorological Society
Abstract: he effect on weather forecast performance of incorporating ensemble covariances into the initial covariance model of the four-dimensional variational data assimilation (4D-Var) Naval Research Laboratory Atmospheric Variational ...