EFP: 2004 Spring Experiment Summary

Working Hypotheses

  1. Numerical modelers can learn to incorporate more operational relevance in their research efforts if they work closely with forecasters in an experimental forecasting exercise.
  2. Operational forecasters can make more skillful interpretations of numerical model output if they work with numerical modelers in an experimental forecasting exercise.

Specific Objectives

  1. Research perspective: To assess the strengths and weaknesses of three different convection-allowing configurations of the WRF model, and to compare the forecast skill of these configurations to that of current operational models in a severe weather forecasting environment.
  2. Operational perspective: to assess whether SPC forecasters can make better predictions of severe convective weather when their current data stream of observational and model data is supplemented with output from convection-allowing forecast models.

Preliminary Results

  1. Addition of high-resolution model output to operational data streams resulted in measurable increases in skill for day 1 human forecasts of severe weather.
  2. In subjective ratings of model performance, the most robust WRF configuration was judged to be more skillful than the Eta model, on average, in all three categories of convective initiation, evolution, and mode.
  3. Weaknesses and deficiencies were identified in all WRF configurations. Model developers were alerted to these problems. As a result, these problems have been corrected and the models continue to improve.

Payoff

  1. The high resolution forecasts generated so much enthusiasm during the 2004 Spring Program that NCEP/EMC has made an effort to run an experimental large domain, high resolution WRF forecast everyday at 0000 UTC since that time. Confidence in this product has increased over time and SPC forecasters are becoming skilled users and interpreters of convection-allowing model forecasts.
  2. Numerous academic participants reported that their experiences in the program would have a significant influence on their research activities and the content of courses they teach.

Related Publications

  • Kain, J. S., S. J. Weiss, J. J. Levit, M. E. Baldwin, and D. R. Bright, 2006: Examination of convection-allowing configurations of the WRF model for the prediction of severe convective weather: The SPC/NSSL Spring Program 2004. Wea. Forecasting, 21, 167–181.
  • Weiss, S. J., J. S. Kain, J. J. Levit, M. E. Baldwin, and D. R. Bright, 2004: Examination of several different versions of the WRF model for the prediction of severe convective weather: The SPC/NSSL Spring Program 2004. Preprints, 22nd Conference on Severe Local Storms, Hyannis, MA, Amer. Meteor. Soc., CD-ROM, paper 17.1