Weather Outlook: 2015 Growing Season Leon F. Osborne Chester Fritz Distinguished Professor Regional Weather Information Center University of North Dakota Grand Forks, North Dakota
Why Should We Be Concerned?
Current Drought Conditions
How is Weather Around the Globe Connected? Oceans serve as major heat sinks/heat sources and are the driving force in controlling the Earth s weather and climate Heat and moisture from the oceans interact with the atmosphere to control the strength and location the planet s jet streams
Atmospheric (and Surface) Temperature Measured from Weather Satellite
Sea-Surface Temperature
Tropical Pacific Sea-Surface Temperatures Intense Tropical Thunderstorms
Tropical Pacific Bridge to Northern Pacific Sea-Surface Temperature Anomaly C
Sea-Surface Temperature Anomaly Changing The Jet Stream
Importance of Jet Streams Represent the location of the Storm Track Pathway for precipitation producing weather systems Responds to seasonal global temperature changes
GOES Infrared Image 9:30 AM CST 15 January 2015
L WARM COLD Jet Stream Orientation of Jet Stream Controls Our Temperature and Precipitation GOES Infrared Image 9:30 AM CST 15 January 2015
North American Storm Track November January 2015 2014 Pattern Cold Air Cold Air Cold Air x Storm Track x Warm Air
Estimating Future Weather The General Process Aggregate available global weather observations and weather model output for analysis and interpretation Identification of predominant orientation of the storm track (i.e. the jet stream) over time Recognizing the availability of atmospheric moisture sources and antecedent soil moisture Translating the findings into conditions relative to longer-term climatology
Northwesterly Flow Provides most dramatic temperature swings Driest flow pattern across the Northern Plains Warm & Dry L Cold & Dry
Zonal (East-West) Flow Moderate temperatures with warming air from the west Generally mild weather with periods of precipitation L Cold & Moist Warm & Moist
Southwesterly Flow Large temperature swings possible with active storm pattern Typically wettest pattern with northward flux of Gulf of Mexico moisture Cold & Dry L Warm & Wet
Weather Outlook 2015
Current Trends Active Yet Mostly Dry - Storm Track Pattern Pacific Ridge is forcing a northwest southeast jet stream flow across the Northern Plains Minimizes moisture available for precipitation Cold Start to 2015 Similar to January 2014 for first half of month before moderating January Thaw In Progress Should continue until middle of next week
Plenty of Frigid Arctic Air Present Across Canada Air Temperature 9 AM CST January 19, 2015
Evolving Global Weather Pattern Short-Lived (Mild) El Niño in Jan / Early Feb Increased west-to-east (zonal) upper-level winds giving milder conditions Continued Areas of Drought & Dry Conditions Limited Snowpack and Snow Cover Deep Arctic Air Mass Very cold air pool available for periodic intensely cold air outbreaks
El Niño Outlook The chance of El Niño is diminishing during the Northern Hemisphere winter Source: NOAA Climate Prediction Center/Columbia Intl. Res. Inst. Updated: 8 January 2015
Snow Depth As of 10 PM CST January 18, 2015 Source: NOAA National Operational Hydrologic Remote Sensing Center
End of the January Thaw Next Week Predicted Air Temperature 3 PM CST Thurs. January 29, 2015
Groundhog Day! Predicted Air Temperature 3 PM CST Monday February 2, 2015
Winter: January March Temperature Outlook Above Near Below Above Near Below
Winter: January March Precipitation Outlook Above Near Below Near Above Below Above
2015: April June Temperature Outlook Near Below Above Near
2015: April June Precipitation Outlook Near Near Below Above
2015: July Sept Temperature Outlook Above Below Much Above Near
2015: July Sept Precipitation Outlook Above Near Below Near Above
In Summary Die has already been cast for the upcoming growing season weather across the Northern Plains Challenge now is interpreting the global signs General Expectations and Concerns... Northern Plains has a high likelihood of near 30-year average weather conditions through the early part of the 2015 growing season Expect normal start to growing season (moisture and temperatures) Concerns on expanding Southwestern & Southern Plains drought and how it could result in expanding drier conditions across the Northern Plains
Thank You! Contact Information 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