Weather Outlook 2016: Cycles and Patterns Influencing Our Growing Season Leon F. Osborne Chester Fritz Distinguished Professor of Atmospheric Sciences University of North Dakota
Cycle of El Niño Events
El Nino Southern Oscillation Changes in Tropical Sea- Surface Temperatures Alter Jet Stream Patterns Comparable El Niños 1997-98 1982-83
Typical North American El Niño Impacts
Recent Strong El Niño Precipitation
Recent Strong El Niño Precipitation
1997-98 El Nino Impacts Flooding in Southern states and California Much above normal temperatures, below normal precipitation across northern US Estimated losses ~$4B but estimated benefits ~$19B
Warm Water Impacts the Storm Track North Pacific Ocean Blob Warmest observed sea surface temperatures since record keeping began in 1950 The Blob
Who Will Win The Battle of the Pacific?
Winter Conditions Set Maybe Not Every El Niño event has its quirks Depends on the varying background global conditions Present El Niño impacts being distorted by warm North Pacific Ocean Must consider other global weather factors North Pacific Ocean water temperatures North Atlantic Oscillation (NAO) Arctic Oscillation (AO) AO has special significance for eastern / central North America
Polar Influence Low Arctic sea ice influences polar temperatures and changes the intensity of polar atmospheric circulations Rate of snow advances in October correlated with linkage between tropospheric and stratospheric polar atmospheric circulation Both drive the orientation and phase of the Arctic Oscillation (AO)
Arctic Oscillation Phases +AO -AO
Outlook... Conditions entering Winter Winter outlook Indications for next Spring and Summer
Warm Autumn Conditions
Similar Snow Advance Trends to 2014
Weather Outlook Winter conditions Big swing in conditions in mid-winter 2016 Spring to Early Summer conditions Declining El Niño by early Summer Lingering AO chance through March Summer conditions depend upon Winter outcome of interaction between El Niño and the Arctic Oscillation
Decay of El Niño by Early Summer
Climate Prediction Center Outlook
Winter Weather Outlook 2015-16 Much Above Above Temperature Below Much Below Below Precipitation Above Gene Much Above Above Much Above
2015 Spring Early Summer Weather Expectations Temperature Below Near Below Near Below Above Above
2015 Spring Early Summer Weather Expectations Precipitation Above Below Near Above
Eastern North Dakota & Northwestern Minnesota Temperatures # of Days
Outlook Issues for the Northern Plains El Niño vs. Arctic Oscillation Major El Niño will it be offset at times by a negative phase Arctic Oscillation? And for how long? Concerns for a swing to La Niña conditions next year Last two major El Niño events resulted in strong La Niña events Increasing drought threat for High Plains during Summer 2016 Will these drought conditions spread eastward?
What Does It All Mean?
Thank You! Prof. Leon Osborne Regional Weather Information Center Department of Atmospheric Sciences University of North Dakota Grand Forks, ND osborne@aero.und.edu 701-777-3181 www.rwic.und.edu Stay informed with RWIC s latest seasonal updates Coming in January. RWIC Weather & Climate Blog