Stephen S. Weygandt

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  • Stensrud, Norman, +16 authors Jason P Tuell
  • 2009
National Severe Storms Laboratory, Norman, Oklahoma; Xue—Center for Analysis and Prediction of Storms and School of Meteorology, University of Oklahoma, Norman, Oklahoma; FoSter—NOAA/NWS, Weather Forecast Office, Norman, Oklahoma; SchaeFer and Schneider—NOAA/NWS/ Storm Prediction Center, Norman, Oklahoma; Benjamin and Weygandt—NOAA/Earth System Research(More)
In this two-part study, a single-Doppler parameter retrieval technique is developed and applied to a real-data case to provide initial conditions for a short-range prediction of a supercell thunderstorm. The technique consists of the sequential application of a single-Doppler velocity retrieval (SDVR), followed by a variational velocity adjustment, a(More)
In this two-part study, a single-Doppler parameter retrieval technique is developed and applied to a real-data case to provide model initial conditions for a short-range prediction of a supercell thunderstorm. The technique consists of the sequential application of a single-Doppler velocity retrieval (SDVR), followed by a variational velocity adjustment, a(More)
A regional ensemble Kalman filter (EnKF) system is established for potential Rapid Refresh (RAP) operational application. The system borrows data processing and observation operators from the gridpoint statistical interpolation (GSI), and precalculates observation priors using the GSI. The ensemble square root Kalman filter (EnSRF) algorithm is used, which(More)
The Rapid Update Cycle (RUC), a high-frequency mesoscale analysis and forecast model system, has become a widely used source for aviation weather forecasting guidance in the United States. It has also become an important part of the overall numerical model guidance provided by the NOAA’s National Centers for Environmental Prediction (NCEP), and has(More)
A coupled ensemble square root filter–three-dimensional ensemble-variational hybrid (EnSRF–En3DVar) data assimilation (DA) system is developed for the operational RapidRefresh (RAP) forecasting system. The En3DVar hybrid system employs the extended control variablemethod, and is built on theNCEP operational gridpoint statistical interpolation (GSI)(More)
41 42 A coupled EnKF-En3DVar hybrid data assimilation system is developed for the 43 operational Rapid Refresh (RAP) forecasting system. The three-dimensional ensemble-44 variational (En3DVar) hybrid system employs the extended control variable method, and is built 45 on the NCEP operational Grid-point Statistical Interpolation (GSI) 3DVar framework. It is(More)
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