Minnesota’s Changing Climate: Winter Impacts
Dr. Mark Seeley Climatologist/Meteorologist Dept of Soil, Water, and Climate University of Minnesota 15th Annual Road Salt Symposium Minnesota Landscape Arboretum Chaska, MN Feb 4, 2016 This day in history
Dress in layers! Lunch outside! 65 degrees F at Tracy, MN -52 degrees F at Detroit Lakes, MN (Lyon County) (Becker County) Feb 4, 1907 Feb 4, 2005
14.0” of snowfall at Severe ground blizzard in Halstad , MN southern MN, closed Hwy 169. (Norman County) 16 deaths Feb 4, 1984 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
NOAA Climate Monitoring and Global and National Assessment Divisions National Climate Assessment 2014
IPCC 5th 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 90th 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. Minnesota State‐Averaged Temperature Trends 1895‐2013 8.0 7.0 6.0 5.0 4.0 century 3.0 per
F
2.0 1.0
degrees 0.0 ‐1.0 ‐2.0 ‐3.0 July May June April March August Annual January October February December November September Maximum Temperature Trend Minimum Temperature Trend Difference (Max minus Min) Trends in average winter minimum temperatures Rochester, MN Period of Record Ave Min Temp in Deg. F 1951 ‐ 1980 Jan 1.9 1961 ‐ 1990 Jan 2.7 1971 ‐ 2000 Jan 3.7 1981 ‐ 2010 Jan 7.7 1951 ‐ 1980 Feb 7.6 1961 ‐ 1990 Feb 8.1 1971 ‐ 2000 Feb 10.6 1981 ‐ 2010 Feb 12.4 1951 ‐ 1980 Mar 19.2 1961 ‐ 1990 Mar 21.3 1971 – 2000 Mar 22.6 1981 ‐ 2010 Mar 24.3 Trends in average winter minimum temperatures Milan, MN
Period of Record Ave Min Temp in Deg. F 1951 ‐ 1980 Jan ‐4.3 1961 ‐ 1990 Jan ‐0.9 1971 ‐ 2000 Jan 0.3 1981 ‐ 2010 Jan 3.7 1951 ‐ 1980 Feb 2.3 1961 ‐ 1990 Feb 5.3 1971 ‐ 2000 Feb 8.2 1981 ‐ 2010 Feb 9.3 1951 ‐ 1980 Mar 15.1 1961 ‐ 1990 Mar 19.2 1971 – 2000 Mar 21.0 1981 ‐ 2010 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 for precipitation in annual Trend Average Annual PPT 1891‐1920, in Average Annual PPT 1921‐1950, in
Avg. Annual PPT, in < 20 21 - 25 26 - 28 29 - 30 Average Annual PPT 1951‐1980, in > 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 (shifting)
(74-145 days)
(9-15”) (10 days) Measurable Measurable Attributes ofAttributes Precipitation
runoff, evaporation) runoff,
interception, absorption, absorption, interception, Quantity (liquid,frozen) Type Intensity Frequency Duration Seasonality relationship Landscape ( 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 Major events still likely as increased water vapor offsets increased temps Severe thunderstorms & tornadoes Return to active conditions likely but unpredictable
Heat waves Expect at least one significant episode, even if within historical Drought 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