We are definitely in need of a drink of water around these parts. It is dry, dry, dry in the Southern Plains.
Now that’s not necessarily unusual for this time of the year. December, January and February are typically the driest months in my part of the Southern Plains. Layer on top of that the fact that we are in a La Nina pattern, which means above normal temperature and below normal precipitation around here, and you have the recipe for extended periods of dry weather.
Still, when you’re like me and work on issues surrounding climate change, you have a tendency to start looking around for any information you can find to see if the weather we’re experiencing is being driven by our changing climate or if this is something to be expected.
As it turns out, this dry weather is something to be expected. As I said earlier, this is the time of year when we should expect to have dry weather AND we are in the middle of a La Nina pattern. Climate change or not, we shouldn’t be to surprised that we haven’t had much (or any) rain. That said, I did come across an interesting article from the USDA Agriculture Research Service (ARS) concerning how climate change is impacting precipitation patterns, especially in the Western United States.
Published last spring, the article cites a study conducted by ARS in cooperation with the University of Arizona that shows how annual rainfall has become more erratic in most of the Western U.S. and how dry periods between rainfall events have increased in length over the last 50 years. The study goes on to state that total yearly rainfall has decreased by an average of 0.4 inches over the last half century, while the longest dry period in each year increased from 20 to 32 days across the Western states.
There was an exception to this weather pattern seen in Washington, Oregon, Idaho, the Northern Plains region of Montana and Wyoming, and the western parts of North and South Dakota. In this area researchers found some increases in annual rainfall and decreases in drought intervals. Interestingly enough, the changes seen in this region actually support what models have predicted as a consequence of climate change: a northward shift in the mid-latitude jet stream, which brings moisture from the Pacific Ocean to the western United States. It was also a change in the jet stream that most experts credited with allowing the “polar vortex” last February that led to the record cold snap in the Southern Plains.
Great. Dry AND cold.
So, while it seems we can’t blame climate change for the dry weather we are having in these parts, climate change IS having an effect on precipitation patterns nation-wide nonetheless.
Will Rogers once said “If you don’t like the weather in Oklahoma, wait a minute.” I guess when it comes to seeing the effects of climate change, you can say the same thing.