Colorado sees drought. Colorado and drought basically go hand in hand. Since 2000, there has been only one short amount of time where there has been no drought recorded in the state and that was from late May to mid July of 2019. Other than that short time, there has been drought occurring in one area of Colorado or another consistently.
So what’s the deal with Flash Drought? Flash drought considers not only the lack of rainfall an area has seen (or not seen, in this case) but also hot temperatures, winds and the rate at which ground water evaporates. Colorado’s drought has been worsening from south to north in this surging drought cycle but a few areas across the state have seen their drought get worse much quicker than other areas.
The Eastern Plains of Colorado (east of I-25) have no significant water source nearby, they’re downwind of the Rocky Mountains, they rely on summer and winter weather patterns to bring them moisture and they are typically warmer and prone to strong winds. The combinations of these elements usually mesh well together but when they are off balance…well, you can see flash drought occur.
There is no definitive measurement of a flash drought but it has become understood that if you see drought conditions worsen by a category or two within a 2-month period, you are seeing flash drought. In the last 3 months, most areas in Colorado have seen their drought worsen by 1 to 2 categories but areas in the Eastern Plains have seen their drought worsen by 3 or 4 categories in that same time period.
The ground holds varying amounts of moisture with most moisture sitting within the first 6 and a half feet as you dig down and that shallow layer of Earth is affected by the sun, the wind and other evaporation processes. Between May and June, winds across the Eastern half of Colorado blew 6-10 mph faster than the normal. Which is a large anomaly and caused the faster loss of groundwater that we saw. On top of that, we have been pretty warm this year as a whole.
We can relate a flash drought to when you blow dry your hair. When you blow dry hair, it dries faster than it would if you didn’t. Well, that’s essentially what happens with the ground. The combination of warm air and wind is creating a full blown hair dryer effect. This combination of no rain, heat and wind can exacerbate drying at a quicker rate (by ~2 times) than just having a lack of rain as the main factor.
Unfortunately, the upcoming forecast is looking rather bleak. The approaching heatwave will likely aid in speeding up drought concerns for northern Colorado and expanding drought concerns in southern Colorado and through October, the Climate Prediction Center is calling for a good change of warmer than average temperatures continuing and a good chance at there being less rain than is typically expected.
Flash drought typically comes within a larger cycle of long-term drought conditions so we may be in this for a while. Since 2000, we have experienced multiple bouts of drought. The 2002 drought didn’t wind down until 2005 but then returned from 2006 to 2008. Then the drought in 2011 lasted until 2015. We saw a quick burst of bad drought from 2018 to 2019 and then went into the summer of 2019 with no drought for the first time in Colorado’s history. Now, we are back on the drought train again. Currently, 80 percent of Colorado is in some kind of drought with close to 70 percent of the state experiencing severe, extreme or exceptional drought conditions.