Winter 2017-2018 Climate Forecast 25 th Winter Weather Meeting, OMSI and Oregon AMS, Portland Kyle Dittmer Hydrologist-Meteorologist Columbia River Inter-Tribal Fish Commission Portland, Oregon Professor of Earth Science PCC Southeast Campus, Portland, Oregon October 28th, 2017
Columbia River Inter-Tribal Fish Commission - CRITFC CRITFC website, http://www.critfc.org
2016-2017 Portland Climate Forecast Performance Month: Temperature (mean monthly): Avg. (n=20) Observed Precipitation (% normal): Avg. (n=20) Observed November Near Normal (-1.8 to + 1.8 degf) -0.2 7 Above Normal (110-130%) 118% 123% December Near Normal (-1.8 to + 1.8 degf) -1.1-3.6 Near Normal (90-110%) 93% 83% January Near Normal (-1.8 to + 1.8 degf) 1.6-7.6 Near Normal (90-110%) 102% 89% February Near Normal (-1.8 to + 1.8 degf) -0.7-3.3 Near Normal (90-110%) 98% 260% March Near Normal (-1.8 to + 1.8 degf) 0.2-0.5 Above Normal (110-130%) 117% 203% but what about Snow events?! Forecasted four events two moderate, two minor (6-inch seasonal total), December to February. Observed five snow events: Dec. 8 (minor), 14 (moderate); Jan. 7 (minor), 10-11 (major); and March 6 (minor) a 11-inch seasonal total. average: 0.0-1.6 average: 106% 152%
2016-2017 Government Camp Climate Forecast Performance Month: Temperature: Observed Precipitation: Observed Snow fall Observed Forecast Observed November -1 5.4 128% 72% 31 26 89% 74% December -1.2-4.9 97% 142% 47 81 98% 168% January 1.7-4.9 103% 59% 50 52 109% 114% February -1.3-2.6 115% 153% 47 52 136% 150% March 0.1-0.9 107% 189% 43 37 130% 111% April -0.6-2.4 95% 112% 25 15 112% 67% May -0.9 1.1 106% 119% 7 1 143% 19% average: -0.5-1.3 107% 121% 250 264 117% 100% Water Supply Forecast (MEI method): Columbia R. at The Dalles, Jan.-July: 111 MAF (issued Oct. 2016), 109%. Observed: 137 MAF. Error ±19%. 101 MAF (issued April 2017), 100%. Observed: 137 MAF. Error ±26%.
Introduction Methods CRITFC 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, of Germany (1922 2004). Track ENSO with the Multi-variable ENSO Index: MEI. NOAA s Sea-Surface Temperature Departure Forecasts. Hydro-Climate approach: Use a regression: Multi-variable ENSO Index (1950-2016) vs. historic runoff for the Columbia River at The Dalles, then compute a 2018 Water Supply Forecast. Select the right mixture of 20 past Water Years (next slide). Pattern recognition is key: both La Niña and ENSO-Neutral years.
Introduction Methods Ensemble forecasting 20 past water years: WY2018 TDA runoff PDO-warm PDO-cold El Nino E-neutral La Nina 1932 106.7 x X 1933 108.4 x X 1943 118.5 x X 1956 141 x X 1960 102.5 x X 1967 113.7 x X 1975 111.9 x X 1981 104.5 x X 1982 134.9 x X 1984 123.7 x X 1986 112.9 x X 1989 93.2 x X 1990 99.7 x X 1993 88.1 x X 1999 124.1 x X 2002 103.8 x X 2006 114.7 x X 2008 99.2 x X 2014 108.1 x X 2017 136.8 x X (MAF) Average: 112.3 ENSO-neutral/LaNina border: 12 STDEV: 13.8 Solar minimums: 5
SUNSPOT COUNTS LA NIÑA http://services.swpc.noaa.gov/images/solar-cycle-sunspot-number.gif
NOAA SEA SURFACE TEMPERATURES - LA NIÑA http://www.cpc.ncep.noaa.gov/products/cfsv2/imagesind3/glbsstmonmaskind4.gif
MEI SIGNAL SUGGESTS LA NIÑA MEI tracks the Sea-Level Pressure, surface winds (2D), Sea-surface Temperature, Air Temperature, and fraction of Cloud cover.
PDO SIGNAL...THE COLD PHASE CONTINUES
ENSEMBLE STREAMFLOW FORECAST Blue line = long-term average (WY 1929-2017)
Summary: the CR Gorge Hood River Month: Temperature (mean monthly): Avg. (n=20) Precipitation (% normal): Avg. (n=20) November Near Normal (-1.8 to + 1.8 degf) 0.1 Above Normal (110-130%) 110% December Near Normal (-1.8 to + 1.8 degf) -1.4 Above Normal (110-130%) 111% January Near Normal (-1.8 to + 1.8 degf) 1.3 Near Normal (90-110%) 99% February Near Normal (-1.8 to + 1.8 degf) -1.6 Near Normal (90-110%) 108% March Near Normal (-1.8 to + 1.8 degf) -0.3 Above Normal (110-130%) 111% Expect many snow events or 135% of normal (NOV-FEB); seasonal total 35-inches. NOV 2.5-inch (up to 8), DEC 11-inch (up to 22), JAN 11-inch (up to 24), FEB 8-inch (up to 17), MAR 2-inch
Summary: the mountains Government Camp Month: Temperature (mean monthly): Avg. (n=20) Precipitation (% normal): Avg. (n=20) Snow fall % Normal November Near Normal (-1.8 to + 1.8 degf) -0.2 Above Normal (110-130%) 119% 31 87% December Near Normal (-1.8 to + 1.8 degf) -0.9 Near Normal (90-110%) 105% 49 101% January Near Normal (-1.8 to + 1.8 degf) 0.8 Near Normal (90-110%) 109% 61 134% February Near Normal (-1.8 to + 1.8 degf) -2.3 Above Normal (110-130%) 113% 52 149% March Near Normal (-1.8 to + 1.8 degf) -0.2 Above Normal (110-130%) 115% 42 126% April Near Normal (-1.8 to + 1.8 degf) -0.5 Near Normal (90-110%) 99% 24 105% May Near Normal (-1.8 to + 1.8 degf) -0.7 Near Normal (90-110%) 107% 7 131% Expect a seasonal total of: 266-inches or 119% of normal (NOV-MAY).
Summary: the Portland Forecast Month: Temperature (mean monthly): Avg. (n=20) Precipitation (% normal): Avg. (n=20) November Near Normal (-1.8 to + 1.8 degf) 0.4 Above Normal (110-130%) 114% December Near Normal (-1.8 to + 1.8 degf) -0.7 Near Normal (90-110%) 99% January Near Normal (-1.8 to + 1.8 degf) 1 Near Normal (90-110%) 102% February Near Normal (-1.8 to + 1.8 degf) -1.4 Near Normal (90-110%) 100% March Near Normal (-1.8 to + 1.8 degf) 0.1 Above Normal (110-130%) 117% EXPECT HIGH VARIABILITY INTENSE RAIN EVENTS, FLOODS, FOG, WIND STORMS, GORGE WIND, FREEZING RAIN, etc. WATER SUPPLY FORECAST: 112 MAF (±14 MAF) or 109%, COLUMBIA RIVER AT THE DALLES, JANUARY - JULY. but what about Snow events?! Expect FIVE events: 3 moderate (3-4 inch), 2 minor (1-inch). DEC 1-inch (up to 2.5), JAN 3.5-inch (up to 8.5), FEB 1.5-inch (up to 4), and MAR 0.5-inch (up to 1) (80% - 95% likely)