"The Development Of A Statistical Postprocessing Algorithm By Two-Step " by William David Stikeleather

Date of Award

8-1-2023

Language

English

Document Type

Master's Thesis

Degree Name

Master of Science (MS)

College/School/Department

Department of Atmospheric and Environmental Sciences

Dissertation/Thesis Chair

Paul E Roundy

Committee Members

Ryan D Torn

Keywords

Empirical Orthogonal Functions, Numerical Weather Prediction, Statistical Postprocessing

Subject Categories

Atmospheric Sciences

Abstract

Model prediction for extended range forecasts is fraught with shortcomings that generate forecast error and decrease skill. Biases in Numerical Weather Prediction (NWP) models generate patterns of error that grow larger with time. These inherent biases systematically alter the modeled positioning of atmospheric features that emerge as synoptic or subseasonal error. While individual weather events and anomalous patterns will generate model noise, it is computationally possible to separate the signal behind this error from noise. For 200 hPa Geopotential Height (Z200), systematic biases in model forecasts often manifest themselves as errors in atmospheric wave patterns in the high latitudes, including inaccurate forecasts of Rossby wave phase speed in the polar jet. Once the predicted structure of the wave pattern in the jet is out of phase with verification, error anomalies grow rapidly with lead time, decreasing the quality of deterministic and ensemble model forecasts entering the long range and subseasonal timescales.

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