1. 452 Precipitation

2. Northwest Weather = Terrain + Ocean Influence

3. Annual Precipitation

4. SW Olympic Slopes-Hoh Rain Forest: 150-170 inches yr -1

5. Sequim: roughly 15 inches per year..

6. Puget Sound Convergence Zone

13. Bias scores for the (a) 1.33- and (b) 4-km model simulations for 1400 UTC 13 Dec 2001 through 0800 UTC 14 Dec 2001.

16. Human Versus Objective Skill for Precipitation Forecasts: NWS Offices Around the US

17. Prob. Of Precip.– Cool Season (0000/1200 UTC Cycles Combined)

18. Brier Scores for Precipitation for all stations for the entire study period.

19. Brier Score for all stations, 1 August 2003 – 1 August 2004. 3-day smoothing is performed on the data.

20. Brier Score for all stations, 1 August 2003 – 1 August 2004, sorted by geographic region. Precipitation

21. Reliability diagrams for period 1 (a), period 2 (b), period 3 (c) and period 4 (d).

22. More than a day out….Human Forecasters Tend to Overpredict 10-30% --exaggerating the threat of rain when it is not likely. “Its probably not going to rain…but I will throw in 10-30% anyway to cover myself” And underpredict rain when it is fairly definite. “Well it looks like it will rain…but I am unsure…so I will knock down the probabilities to 60-80% to cover myself” Rain Psychology

23. Humans Help with Heavier Precipitation

30. Convective Precipitation Need at least 2-4 km resolution to get most convection even half right. If grid spacing is more coarse must have cumulus parameterization--Kain-Fritsch is used for MM5. Convection is least skillful precipitation in virtually all models. High resolution models can potentially give a heads on type of precipitation a day ahead (squall line, supercell, etc.)

31. Real-time WRF 4 km BAMEX Forecast Composite NEXRAD Radar 4 km BAMEX forecast 36 h Reflectivity 4 km BAMEX forecast 12 h Reflectivity Valid 6/10/03 12Z

32. Real-time 12 h WRF Reflectivity Forecast Composite NEXRAD Radar 4 km BAMEX forecast Valid 6/10/03 12Z 10 km BAMEX forecast 22 km CONUS forecast

33. Hurricane Isabel Reflectivity at Landfall Radar Composite 18 Sep 2003 1700 Z 41 h forecast from 4 km WRF

34. The End