1. Winter 2012-2013 Climate Forecast Kyle Dittmer Hydrologist-Meteorologist Columbia River Inter-Tribal Fish Commission Portland, Oregon November 17th, 2012 Oregon-AMS Meeting, OMSI, Portland

2. 2011-2012 Climate Forecast Performance …but what about snow events?! Forecast three events…1 to 5 inches each, December to early March. Observed EIGHT snow events…9.5 inch seasonal total. Month:Temperature (mean monthly):Avg. (20-yr)ObservedPrecipitation (% normal):Avg. (20-yr)Observed NovemberNear Normal (-1.8 to + 1.8 degF)0.6-0.9Above Normal (110 - 130%)113%117% DecemberNear Normal (-1.8 to + 1.8 degF)0.5-1.1Above Normal (110 - 130%)124%44% JanuaryNear Normal (-1.8 to + 1.8 degF)-0.3 Near Normal (90 - 110%)106%146% FebruaryNear Normal (-1.8 to + 1.8 degF)-0.7Near Normal (90 - 110%)105%71% MarchNear Normal (-1.8 to + 1.8 degF)-1.3-3.2Above Normal (110 - 130%) 111%214% average:-0.3-1.2 average:112%118% Water Supply Forecast (MEI method): Columbia R. at The Dalles, Jan.-July: 117 MAF (issued Oct 2011), 109%. Observed: 129 MAF. Error ±9%. 132 MAF (issued April 2012), 130%. Observed: 129 MAF. Error ±2%.

3. Introduction – Methods Forecast uses a holistic, integrated big picture view. Big-picture: Solar Forcing (e.g., sunspot cycles) does influence our global weather patterns. In memoriam: Dr. Landscheidt, 1922 – 2004, of Germany. Track ENSO with the Multi-variable ENSO Index. Sea-Surface Temperature Departure Forecasts. Hydro-Climate approach: Water year 2013 volume forecast uses regressed Multi-variable ENSO Index vs. historic runoff for the Columbia R. at The Dalles. Average of 20 water years = the volume forecast. Pattern recognition is key: El Niño & ENSO-neutral.

4. SUNSPOT COUNTS – SUGGEST EL NIÑO http://solarscience.msfc.nasa.gov/images/ssn_predict_l.gif

5. SEA SURFACE TEMPERATURES SUGGEST ???? http://www.cpc.ncep.noaa.gov/products/people/wwang/cfs_fcst/images3/glbSSTMonMask.gif

6. ENSO SIGNAL SUGGESTS ENSO-NEUTRAL WINTER WEATHER MEI tracks the Sea-Level Pressure, surface winds (2D), Sea-surface Temperature, Air Temperature, and fraction of Cloud cover.

7. PDO SIGNAL...THE COLD PHASE GETS COLDER!

8. ENSEMBLE STREAMFLOW FORECAST Blue line = long-term average (WY 1929-2012)

9. Summary: The Forecast …but what about snow events?! Expect FOUR events…1 moderate (2-5 inch), 3 minor (1 inch) (70-80% likely), January through mid-March. EXPECT HIGH VARIABILITY IN THE WEATHER...BUT NOT EXTREME – HEAVY RAIN EVENTS, FLOODS, etc. WATER SUPPLY FORECAST: 102 MAF or 95%, COLUMBIA RIVER AT THE DALLES, JANUARY - JULY.