A Local WRF Downscaling of the Global Ensemble Forecast System Members Using Modest Computer Resources
Supplemental Data

Stephen E Masters, Dr. Stephen Masters Consulting, LLC, Melbourne, FL, USA

Abstract

The Global Ensemble Forecast System (GEFS) produces 21 global forecasts during each 6-hour forecast cycle. The variability among the members may give the forecaster an estimate of some of the uncertainty in the forecast. However, examining the 6-hour global forecast output may not give a satisfactory picture of the likely forecast uncertainty on the local scale. This poster describes a system that uses the Weather Research and Forecast (WRF) model to effectively downscale the GEFS members over a small region. The system produces local ensemble forecasts of hourly temperatures, winds, and precipitation through the 144-hour period of the GEFS using very modest computing resources. The data and model processing are described and examples of a forecast are given. Surface verification statistics over a 6-month period for selected stations over the United States are given.

Click on the image for a handout-sized PDF of the poster.

 

Statistics at individual stations

Each file contains the verfication statistics for one of the stations on the map at left. Some of the statistics included are:

  • Surface wind direction bias, RMSE by ensemble member, by initialization date, and by forecast hour
  • Surface wind speed bias, RMSE by ensemble member, by initialization date, and by forecast hour
  • Surface wind vector error RMSE by ensemble member, by initialization date, and by forecast hour
  • Surface temperature bias and RMSE by ensemble member, by initialization date, and by forecast hour
  • Surface dew point bias and RMSE by ensemble member, by initialization date, and by forecast hour
KBQP KBWG KCHS KCMD KDNN
KEYW KFAM KFQD KGWO KHRO
KIXA KJKL KLIT KMCO KMLB
KMRC KMSY KPNS KPNN KPSK
KRIC KRUQ KTLH KTYS KSBO

Some overall statistics

Overall temperature stats by initializaion date. Temerature bias and RMSE for all stations, all forecast hours, all ensemble members. These statistics include data from all surface reporting stations within the WRF computational domain.

Latest WRF GEFS downscale forecasts

Latest WRF GEFS forecasts. Here you will find the current WRF forecasts derived from the GEFS members. Point forecasts are generated for ten stations over the southeastern United States

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