9.6
Preliminary results from 4 km explicit convective forecasts using the WRF model
Morris L. Weisman, NCAR, Boulder, CO; and W. Wang and J. B. Klemp
The Weather Research and Forecast (WRF) model is being specifically designed to improve predictability of phenomena that can can be represented with horizontal grid resolutions of 1 to 10 km. Convective weather remains a real challenge for such a modeling system, and is recognized as a major contributor to poor forecasts of warm season QPF. In order to test the current capabilities and limitations of the WRF model for such scenarios, 4 km resolution simulations are being run, and will include much of the upcomming warm season, centered on the western high plains, congruent with IHOP research domain. 4 km grid resolutions are nominally considered sufficient to represent mesoscale convective systems, and was used successfully with the WRF model to forecast a large bow-echo system that moved through South Dakota, Wisconsin and northern Illinois on 11-12 June 2001. These tests document the capabilities and limitations of WRF to forecast the timing, location, and mode of major convective activity, as well as reproduce appropriate vertical profiles of temperature, moisture and winds in the environments of the convection. Running such a test in conjunction with IHOP enhances the ability to verify specific forecasts, and test proposed improvements to model physics. Our experiences will be compared to those using other convective-resolving forecast models, which will help clarify directions for further research and model development
Session 9, WRF Model Development
Wednesday, 14 August 2002, 3:30 PM-6:00 PM
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