Drought Development in Colorado
Colorado receives precipitation through snow and rain. Drought can develop in diverse ways, which makes predicting drought challenging. For example, 2018, was a dry winter on the western slope, where dry conditions were expected in the summer. Conversely, in 2020, we received average snowpack in the winter, but hot and dry conditions in the spring and summer of 2020, coupled with a dry fall in 2019, led to a severe drought in 2020.
In short, ‘average’ snowpack does not necessarily translate to average streamflows or mean that we won’t experience drought conditions. Further, streamflow forecasts don’t always track with forage conditions. An example of this was 2015 where streamflows were relatively low, but extraordinary rains in May 2015 led to above average forage production on rangelands. The bottom line is that drought in Colorado can develop in diverse ways.
What are our current conditions?
Find current drought conditions and tools including an interactive map available on the Colorado Climate Center website. You also can find the Drought Monitor, an assessment released weekly, using precipitation, evapotranspiration and other data, and local impact reports. The Drought monitor is connected to federal relief spending with drought disaster programs administered by the Farm Service Agency (FSA).
What are current forage conditions?
U.S. Geological Survey tool VegDri can be used to look at drought stress on plants. For example, it can be used to assess locally if there are microclimates where vegetation is less or more stressed due to drought. Find additional information and see maps at https://www.usgs.gov/core-science-systems/eros/droughtstress.
What are current the streamflow forecast?
The NRCS Snow Survey Program monitors snowpack to generate streamflow forecasts for Colorado, and the data available may be useful for informing irrigation management among Colorado producers.
What are my historical conditions?
Find precipitation and temperature information for your location using the Colorado Climate Center’s data. You can search stations in western Colorado and get data going back to as long as that station has been in business. As an example, the Grand Junction – Walker Field Station has collected data since 1900.
Another option is the High Plains Regional Climate Center maps, which aggregate data of the current year compared to 1981-2010. You can create your own map comparing current / recent temperatures to historic conditions to understand how this year and month for example compare to historical averages.
How likely are conditions to continue, and what do they mean in terms of what I can expect?
The drought outlook is a monthly forecast and is based on long-term cycles that influence weather in north America. You can find the drought forecast on NOAA’s Climate Prediction Center website.
Long-term forecasts in Colorado have greater accuracy in winter months in our region). In other words, winter forecasts of La Niña/El Niño have greater ability to predict winter weather, whereas long-term summer forecasts historically have not been reliable (Crimmins and McClaran[1] 2016). Recent research demonstrates how long-term forecasts like the Pacific Decal Oscillation and El Niña/ La Niña can inform information on forage production on rangelands earlier in the year and potentially before the grazing season begins.
Additional information is available in the Extension publication, “Early Warning for Stocking Decisions in Eastern Colorado”. https://extension.colostate.edu/docs/pubs/livestk/03115.pdf
[1] Crimmins, Michael A and McClaran, Mitchel P. (2016) Where do seasonal climate predictions belong in the drought management toolbox. Available at https://www.sciencedirect.com/science/article/pii/S0190052816300268
