1. Univ of AZ WRF Model Verification

2. Method NCEP Stage IV data used for precipitation verification – Stage IV is composite of rain fall observations and radar estimates – Data has a resolution of 4km – http://www.emc.ncep.noaa.gov/mmb/ylin/pcpanl/stage4/ http://www.emc.ncep.noaa.gov/mmb/ylin/pcpanl/stage4/ Nearest neighbor is used to move stage iv data to model data to observation site Verification was performed on 12 hour accumulations at various forecast hours – For the 24 hr model forecast, verified the amount of precipitation accumulated for the 12 hr period ending at the time the 24 hour forecast is valid (i.e. for a 24 hr fcst from a 15 Nov 00Z model run, verify the precipitation that fell during the period 15 Nov 12Z – 16 Nov 00Z Statistics generated for several precipitation thresholds: >1mm, >6.25mm(.25in), >12.5mm(.5in),>25mm(1in)

3. Nov 25 12Z Model Run WRF 5.4 km On the following displays, the solid color is the model forecast Dots and other symbols are the Stage IV precipitation observations – The color and shape of observations symbols represent the amount of precipitation accumulated in a 12 hour period ending at the forecast valid time Statistics calculated for data displayed in the image

4. Model Run: 20081125 12Z Forecast: 18hr Accumulation Period: 20081125 18Z – 20081126 06Z Model Run: 20081125 12Z Forecast: 24hr Accumulation Period: 20081126 00Z – 20081126 12Z

5. Model Run: 20081125 12Z Forecast: 36hr Accumulation Period: 20081126 12Z – 20081127 00Z Model Run: 20081125 12Z Forecast: 30hr Accumulation Period: 20081126 06Z – 20081126 18Z

6. Model Run: 20081125 12Z Forecast: 48hr Accumulation Period: 20081127 00Z – 20081127 12Z Model Run: 20081125 12Z Forecast: 42hr Accumulation Period: 20081126 18Z – 20081127 06Z

7. Nov 25 12Z Model Run WRF 1.8 km

8. Model Run: 20081125 12Z Forecast: 18hr Accumulation Period: 20081125 18Z – 20081126 06Z Model Run: 20081125 12Z Forecast: 24hr Accumulation Period: 20081126 00Z – 20081126 12Z

9. Model Run: 20081125 12Z Forecast: 30hr Accumulation Period: 20081125 06Z – 20081126 18Z Model Run: 20081125 12Z Forecast: 36hr Accumulation Period: 20081126 12Z – 20081127 00Z

10. Model Run: 20081125 12Z Forecast: 42hr Accumulation Period: 20081126 18Z – 20081127 06Z

11. Domain Verification Period of verification is from 15 Oct – 28 Nov 2008 During this period there were two major precipitation events over the area of interest Not sure why the 30hr forecast shows higher skill compared to other forecasts – Probably due to the limited number of forecasts with precipitation for period