Extension Climate Science Team And effort to describe past and future climate trends that affect different sectors of the State’s economy Water, Forestry, and Agriculture Partnership of MSU and UM through the IoE A series of listen session across the state for each sector drove the questions that were examined. “What do you need to know about climate change to make decisions that affect you and your operation” The premise is we need to know the state of knowledge on how climate is changing and how that affects these sectors before we can develop bmp to adapt or migrate to the change. Brad Bauer – MSU Extension Gallatin County / Climate Team

Climate Science state.climatologist@umontana.edu

Montana Climate Office Kelsey Jencso State Climatologist Mike Sweet Information Services Nick Silverman Hydroclimatologist Kevin Hyde Mesonet Director

What is climate? Climate is the average weather patterns for a region over many years. Variability Climate Variable Average 10 20 30 Years

Climate Weather

Climate variables Sea-surface temperature Temperature Greenhouse gases Precipitation Sea-surface temperature Greenhouse gases Snow and ice Land cover Soil moisture Etc………. Wind Pressure Solar radiation Humidity The World Meteorological Organization (WMO) defines 50 essential climate variables

More Climate Basics

Climate Science

Localized climate records Kalsta ranch journals, dating back to the 1880s, note everything from late frost that “took a nip off the alfalfa,” to river levels. Sarah Jane Keller Localized climate records Ranch records Weather Stations Proxy records – journals, tree rings Sarah Jane Keller

Weather Stations Station Details Station Name: LEWISTOWN MUNI AP, MT USA Element Start End Years Observations PRCP:Precipitation (tenths of mm) 1896-1-8 2/21/2017 121 43,054 SNOW:Snowfall (mm) 1896-1-11 1/22/2017 21,854 TMAX:Maximum temperature (tenths of degrees C) 1896-2-1 42,773 TMIN:Minimum temperature (tenths of degrees C) 42,792

Weather Stations Station Details Station Name: MSU Element Start Years Observations PRCP:Precipitation (tenths of mm) 1892-4-8 125 44,606 SNOW:Snowfall (mm) 1892-5-1 30,059 TMAX:Maximum temperature (tenths of degrees C) 44,631 TMIN:Minimum temperature (tenths of degrees C) 44,673

Montana Temperature (1950-2015) Between 1950 – 2015: Average annual temperature has increased by 0.42⁰F per decade over the last 65 years. This is an overall increase of 2.7⁰F over this time. US annual average has increased at a rate of 0.26⁰F per decate since 1950

Montana Temperature (1950-2015) Between 1950 – 2015: Annual Maximum and Annual Minimum have increased over this time period 0.3⁰F - 0.6⁰F per decade Winter and springs have warmed the most Montana’s growing seasons are 11 days longer

Montana Precipitation Our current aveage annual precipitaiton is 18.7 inches Between 1950 – 2015: Statewide, the amount of average annual precipitation has shown no statistically significant trend over the past 65 years

Montana Precipitation (1950-2015) Spring Precipitation Eastern MT Increases Winter Precipitation North western and central MT decrease No changes in summer and fall

Climate Variability Climate Variable Average 10 20 30 Years

Climate Change Variability Average Climate Variable 10 20 30 Years

Montana Climate Projections 20 different models make up the ensemble This gives us a range of projections Downscaled 4km resolution using statistical downscaling but aggregated to the Climate Division Two RCP scenarios (4.5 and 8.5) Comparison of mid- and end-of-century time periods Historical (1971—2000) Mid-century (2040—2069) End-of-century (2070—2099)

Change Avg. Annual Temperature (oF) Mid-Century RCP 8.5

Change in # of Days Above 90 oF Mid-Century RCP 8.5

Change in # of Freeze Free Days Mid-Century RCP 8.5

Change in Monthly Avg. Temp. (oF) Mid-Century RCP 8.5

Change Avg. Annual Precipitation (%) Mid-Century RCP 8.5

Change in # of Days Above 1.0” Mid-Century RCP 8.5

Change in # of Consecutive Dry Days Mid-Century RCP 8.5

Provisional Summary of Climate Projections For Montana – By 2050 Temperature has increased historically and is projected to increase by another 4-6 oF by mid-century. Precipitation has stayed about the same historically but is projected to increase by around 6-10 % by mid-century. Drought metrics (i.e. consecutive dry days) are not projected to change much but are highly uncertain. Similar future climates are located both close and far away

What does it mean for water? Example ‘lead-in’ slide to each issue – we should have a similar one for forests and agriculture

Montana Water Trends & Projections Between 1950-2015: Snowpack has declined, especially since 1980s. Earlier spring runoff. Streamflow is influenced by warming & climate variability (e.g., El Nino). Future: Snowpack will continue to decline with earlier snowmelt. Streamflow may increase, esp. in spring/early summer. Late-summer water availability will decrease. Droughts will be exacerbated by warming. Demands for groundwater will increase.

Brad Bauer brad.bauer@montana.edu 406-582-3283 http://msuextension.org/climate/