Ghidey, Tesfamichael, Nicholas Loyd, Gerrit Hoogenboom,
AgWeatherNet, Washington State University and Heping Liu, Washington State
University
In the eastern
Washington tree fruit agricultural area, availability of weather forecasts to
predict for damaging spring and fall frost conditions is important in decision
making. To address this need, the state-of-the-art next generation mesoscale
meteorological model known as the Advanced Research Weather Research and
Forecasting (WRF-ARWv3.3.1) was implemented to verify its performance over the
state of Washington. A combination of two large scale initial conditions and
seven combinations of physics schemes in three nested domain resolutions were
used to evaluate the performance of the model for frost and freeze prediction
in eastern Washington. WRF was configured with three nested domains of 27, 9
and 3 km horizontal resolutions with the third nested domain covering only the
state of Washington. Vertically, 40 sigma levels were used that extended to 50
mb into the free atmosphere as the model top. In this investigation, four
freeze weather events were selected, representing spring and fall frost as well
as winter arctic outbreak conditions critical for tree fruit industry.
Preliminary results showed that the model predicted well over the Columbia
basin flat region when it forecasted two days ahead of the freeze day, with the
two physics options analyzed showing minimal different in performance.