2. TAHOE REGION PRECIPITATION PROJECTIONS Client: North Lake Tahoe Resort Association Joey Spitze SJSU - Department of Meteorology

3. BACKGROUND Question: Will the Tahoe region have to shift its economy away from winter sports in order to stay stable. Tahoe region employment and earnings due to visitors are made from retail (21%), lodging accommodations(22%), food services(22%), and recreation (35%), both summer and winter. (2009, Dean Runyan Associates) 16 million Americans participate in recreational snow sports…generating 560,000+ jobs and $8.8 billion in federal and state taxes. (2006, Southwick Associates)

4. Methods 80 Years (2010-2089) Averaged over 7x7 grid over Tahoe region Downscaled CMIP5 monthly data 1/8 Degree BCSD projections Chose only models with 3+ ensembles Compared RCP 2.6 and RCP 8.5 Averaged annually and averaged over winter months

5. RCP 2.6

6. RCP 8.5

7. RCP 2.6

8. RCP 8.5

9. RESULTS RCP 2.6 Annually averaged data: Positive trends for 3 models. No statistically significant positive or negative trend in precipitation by the month or by the winter season. RCP 8.5 Annually averaged data: Positive trends for 5 models. Winter season data: Positive trends for January, February and March. Negative trends for November and April. Both the November through April and the DJF trends were positive as well.

10. FUTURE WORK Apply minimum and maximum temperatures and correspond with precipitation data. This was recently added, please see http://blizzard.met.sjsu.edu/~hspitze/CMIP5.htm http://blizzard.met.sjsu.edu/~hspitze/CMIP5.htm Compare and contrast with RCP 4.5

11. The End