Minnesota s Changing Climate: Winter Impacts Dr. Mark Seeley Climatologist/Meteorologist Dept of Soil, Water, and Climate University of Minnesota 15 th Annual Road Salt Symposium Minnesota Landscape Arboretum Chaska, MN Feb 4, 2016
This day in history Lunch outside! 65 degrees F at Tracy, MN (Lyon County) Feb 4, 2005 Dress in layers! -52 degrees F at Detroit Lakes, MN (Becker County) Feb 4, 1907 Severe ground blizzard in southern MN, closed Hwy 169. 16 deaths Feb 4, 1984 14.0 of snowfall at Halstad, MN (Norman County) Feb 4, 2008
Topics to be covered: Temperature trends and patterns Precipitation trends and patterns Consequences
RECENT SIGNIFICANT CLIMATE TRENDS IN MINNESOTA AND THE WESTERN GREAT LAKES TEMPERATURE: WARM WINTERS AND HIGHER MINIMUM TEMPERATURES MOISTURE: AMPLIFIED PRECIPITATION SIGNAL, THUNDERSTORM CONTRIBUTION
Minnesota weather and climate history National Climate Assessment 2014 NOAA Climate Monitoring and Global and National Assessment Divisions IPCC 5 th Assessment Information Resources Used
Geographic Disparity in Temperature Change From IPCC AR5 Report
Seasonality in temperature change (IPCC-2007) Figure 3.10
Disparity in the pace of climate change relative to temperature
Minnesota Mean Annual Temperature Trends Temp trend is upward and more frequently above the 90 th percentile, pace is 2 F per century.
Winter Spring Seasonal Statewide Temperature Trends in MN Summer Fall
Statewide Change in average winter minimum temperature is 5 F per century
LARGE CONTRIBUTION FROM WARM WINTERS Top 12 warmest Dec-Feb periods in Minnesota since 1895 based on aggregate mean temperature (F) 1997-1998 22.2 2001-2002 21.4 2011-2012 21.2 1986-1987 20.9 1930-1931 20.1 1991-1992 18.8 1982-1983 18.6 1999-2000 18.2 2005-2006 17.8 1943-1944 17.0 1998-1999 16.7 1920-1921 16.5 *Historical median value 10.3 F, the last winter below that value was in 2013-2014.
January February March April May June July August September October November December Annual 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 1.0 2.0 3.0 Minnesota State Averaged Temperature Trends 1895 2013 Maximum Temperature Trend Minimum Temperature Trend Difference (Max minus Min) degrees F per century
Trends in average winter minimum temperatures Rochester, MN Period of Record 1951 1980 1961 1990 1971 2000 1981 2010 1951 1980 1961 1990 1971 2000 1981 2010 1951 1980 1961 1990 1971 2000 1981 2010 Ave Min Temp in Deg. F Jan 1.9 Jan 2.7 Jan 3.7 Jan 7.7 Feb 7.6 Feb 8.1 Feb 10.6 Feb 12.4 Mar 19.2 Mar 21.3 Mar 22.6 Mar 24.3
Trends in average winter minimum temperatures Milan, MN Period of Record 1951 1980 1961 1990 1971 2000 1981 2010 1951 1980 1961 1990 1971 2000 1981 2010 1951 1980 1961 1990 1971 2000 1981 2010 Ave Min Temp in Deg. F Jan 4.3 Jan 0.9 Jan 0.3 Jan 3.7 Feb 2.3 Feb 5.3 Feb 8.2 Feb 9.3 Mar 15.1 Mar 19.2 Mar 21.0 Mar 22.0
Frequency of temperatures -30 F or colder at Pokegama Dam, MN 1887-1950 average 9 nights per year 1951-2014 average 2 nights per year Frequency of temperatures -30 F or colder at Grand Rapids, MN 1915-1950 average 5 nights per year 1951-2014 average 3 nigthts per year
Remember February 2, 1996? Location Low Temperature Littlefork -50 F Grand Rapids -41 F Thorhult -51 F Park Rapids -51 F Embarrass -54 F Tower -60 F Leech Lake -46 F Cass Lake -48F Remer -51 F
Net Change in Precipitation Over Land From IPCC-AR5 Report
Geographic Disparity in Precipitation Change-IPCC 2013
Trend in annual precipitation for MN
Average Annual PPT 1891 1920, in Average Annual PPT 1921 1950, in Avg. Annual PPT, in Average Annual PPT 1951 1980, in < 20 21-25 26-28 29-30 > 30 Average Annual PPT 1981 2010, in Source: MN-SCO
Winter (D,J,F) Spring (M,A,M) Seasonal Trends in MN Precipitation Summer (J,J,A) Fall (S,O,N)
Change in Annual Precipitation Normals at Milan, MN PERIOD AMOUNT (IN.) 1921-1950 21.53 1931-1960 23.57 1941-1970 25.53 1951-1980 25.13 1961-1990 24.12 1971-2000 24.71 1981-2010 26.14 21 percent increase since 1921-1950 Extremes 7.91 in 1976, 39.58 in 1995
Change in Annual Precipitation Normals at Faribault, MN PERIOD AMOUNT (IN.) 1921-1950 24.80 1931-1960 27.06 1941-1970 29.49 1951-1980 30.30 1961-1990 31.00 1971-2000 31.67 1981-2010 32.63 31 percent increase since 1921-1950 period Extremes: 10.81 in 1910, 42.20 in 1951
Change in Annual Precipitation Normals at Windom, MN PERIOD AMOUNT (IN.) 1931-1960 25.70 1941-1970 26.49 1951-1980 26.28 1961-1990 29.00 1971-2000 28.89 1981-2010 30.62 19 percent increase since 1931-1960 period
Measurable Attributes of Precipitation Quantity Type (liquid,frozen) Intensity (9-15 ) Frequency (74-145 days) Duration (10 days) Seasonality (shifting) Landscape relationship (interception, absorption, runoff, evaporation)
Radiosonde history of PW at MSP since 1948 Most record high values have occurred since 1990
Snapshot of expectations: <10 years Strength of expected impact from climate change Highest High Moderately High Moderately Low Low Lowest Hazard Expectations through 2024 Extreme cold Continued decline in severity, frequency Extreme rainfall Unprecedented events possible Heavy snowfall Severe thunderstorms & tornadoes Major events still likely as increased water vapor offsets increased temps Return to active conditions likely but unpredictable Heat waves Drought Expect at least one significant episode, even if within historical bounds From MN State Climatology Office
Features of change in winter climate of Minnesota Change in depth and duration of soil and lake freezing Increased frequency of freeze/thaw cycles Shorter continuous snow cover season More frequency intense precipitation events on the perimeter of winter More frequent mixed precipitation (liquid/frozen), and heavy snowfall events in the core of winter Change in storm sewer runoff design and culvert design for higher capacity to discharge runoff