AUSTIN (KXAN) — Every Thursday morning, the U.S. Drought Monitor map gets updated to show any improvement or deterioration of the drought nationwide. Lately, most of Central Texas was downgraded to the worst level of drought “Exceptional.” Meteorologist Nick Bannin spoke with Brian Fuchs from the National Drought Mitigation Center about the factors that go into the drought map and what it would take to get us out of drought.
Nick Bannin, KXAN Meteorologist: Brian, what factors go into the drought monitor that’s released every week?
Brian Fuchs, Climatologist with the National Drought Mitigation Center: So yeah, the Drought Monitor is quite complicated, and it is actually a partnership between the National Drought Mitigation Center, the USDA, or Department of Agriculture, and NOAA. And our groups come together, and we kind of put together…the process of what we look at and it’s very much a data-driven process. That means that, again, precipitation is going to be one of the big things that factor into the making of the map each week, but we look at dozens of different indicators, different drought indices, things like soil moisture, groundwater, river and streamflow. We have satellite data and there’s a plethora of data that we do put together and analyze in the making of the map each week.
Bannin: Can you explain the difference between the short-term and long-term drought [labeling] that go on the map?
Fuchs: Over the years, when we’ve been putting this map out, there are different types of droughts that take place. We have droughts that start developing, and they they’re getting worse, and then they maybe go away. And then we have droughts that develop, they stick around, they stick around maybe a year or so later, we’re still seeing those. And so we determined that there has to be a timescale associated with what the predominant impacts are, you know, what are the problems that we’re seeing due to that drought.
And so with short-term drought, we typically are seeing that the main impacts coming from the dryness or on a scale of six months or less. For a long-term drought…we’re saying that the main impacts associated with what’s going on in a region are on a timescale greater than six months. And then sometimes you see both the “S” and “L” labels together on the map and that’s saying that, yes, there’s been short-term dryness and long-term dryness and combined, that is causing all the problems that we’re seeing in an area. And you know, that’s what we’re seeing a lot right now over the Southern Plains has been this both short and long-term dryness.
Bannin: Now, other than updating the Drought Monitor, which is what we’re so familiar with, what else does the National Drought Mitigation Center do?
Fuchs: So the Drought Mitigation Center does have many different avenues that we work on. Of course, the Drought Monitor probably gets the most notice because it is weekly and gets out in front of millions of people. But we also work with different states and agencies on drought planning, you know, how do you better prepare for drought? What needs to be in your drought plan? How do you set triggers and things like that?
We also have an education and outreach component where we work with everything from K-12 students to college students and even adult education. There are many groups out there that are interested in the Drought Monitor and the work we do here at the center, and so we try to reach out to them. We also have a social science component, meaning that we have all of these great scientists that are doing this work with drought, but how do we better relay that information to those that maybe aren’t scientists and maybe need to utilize the information? And so we have a whole team of social scientists as well that they kind of bridge what the physical scientists like myself, how we relay that information and data to those that maybe aren’t as familiar with this information. And all in all, we also work overseas, we work with countries all over the world to try to replicate what we’re doing here in the United States in their own countries.
Bannin: Can you speak to the drought that we’ve seen some parts of the country dealing with? Obviously, the West saw big improvement over the winter with the deluge of storms and atmospheric rivers, but here in Central Texas, our droughts [have] only been getting worse over the last few months. Can you put our drought into some historical perspective?
Fuchs: Yeah, so when we look at what’s been going on in Texas, and again, when we talk about Texas, that’s even difficult because it is a large state. And there’s a lot going on across the state that… if you’re in the northern Panhandle, you’re probably thinking, ‘wow, things aren’t too bad right now,’ but like you said, if you’re in Central Texas, you’re really wondering, ‘well, when are we going to have this drought break?’
And so you know, many in the Texas area, when you start talking about the most recent droughts and how this one compares, many do go back to that that 2010 -2011 time era, and some parts of Texas, we’re seeing that drought continued all the way through 2015. It really peaked in that 2011-2012 timeframe and currently, we’re not really approaching the level of magnitude of the drought that we saw, you know, a decade or so ago. But we are seeing some parts of the state that are approaching some of the data and some of the indicators are starting to have similarities to that. And I think one of the key features to that 2011 drought was just how long it lasted that it just seemed like there was very little relief. And it was the entire region, it was, you know, Texas, Oklahoma, parts of New Mexico. And it just kind of stayed entrenched where this one, like I said, parts of the state haven’t been too bad off. Again, the heat over the last several weeks has really started to change that landscape, though.
Bannin: How do you calculate what amount of rainfall it would take to end a drought? Or is that an impossible calculation?
Fuchs: Yeah, that’s a tough question, because precipitation, again, is a key input into the making of the Drought Monitor. We’re not trying to replicate on the map where it rained and didn’t rain, so that there’s a lot that goes into it, I mentioned the other data. And so saying, with certainty, ‘Hey, we need 10 inches of rain to end this drought,’ it really does make a difference on how that precipitation comes, you know, five inches of rain over three hours is different than five inches of rain over a 10 day period, and how that water can get into the ground, it can help all the different systems and ecosystems that are that have been impacted by the dryness.
So it is really hard to put a number on just how much rain we need. It really is dictated by how that rain comes. And just the antecedent conditions, I guess, the conditions that were in place prior to that rainfall coming, you know, how much rain is even going to take to start infiltrating into the ground. You know, during these drought episodes, we see the ground get crusted over, and it’s harder for that rain, to even get into the soils. And again, a lot of that runs off, which is great for rivers and streams and reservoirs and lakes, but getting into the soil where plants, animals and an agriculture can utilize that moisture that is much more difficult.
Bannin: Now, much of Central Texas right now is in the top two stages of drought ‘extreme’ or ‘exceptional.’ How rare are those types of droughts? Or are some areas more likely to see them than others, and is it not so rare in some places versus others?
Fuchs: Well, we do know that, you know, the Plains area has had a lot of drought since the Drought Monitor has been around in the last 25 years. So, it seems like the last few decades, drought has been more common than it hasn’t been, and I think a lot of people are getting used to, you know, having these dry summers and drought developing. But when we start talking about the different intensity levels on the Drought Monitor, when you see that D3 ‘extreme’ drought on the map, that is a rare event, meaning that the majority of the indicators that we are looking at are falling and that that top three to fifth percentile, top three to five dry events ever for that area. And we tend to see those about once every 25 or 30 years, statistically speaking.
Now when we get to ‘exceptional’ drought, it even gets more rare, meaning that the current conditions of the data that we’re looking at, through all the indicators and indices that we have, are falling in the top one or two driest of all time for that area. And what’s unique about how the Drought Monitor puts this information together, is it’s all gauged on what the local climate is, and the local conditions are, so we’re not comparing dryness in Texas to that of Georgia or Maine or even Washington State or anything like that. Everything is geared towards what the local climate should be, and what we’ve seen in the past, and how the current conditions are stacking up to what we have seen in that region over the last few years.