NEW MEXICO (KRQE) – More than half of New Mexico is currently experiencing “exceptional” drought, according to the US Drought Monitor. In fact, by some measures the current drought is historic: More of the state has experienced “exceptional drought” in the last two months than in 99% of the historical record going back to 1895, according to data from the Drought Monitor. Yet snowpack in the Rio Grande Headwaters is at 96% of the median level, according to the March 2021 New Mexico Basin Outlook Report. So why are we in a drought?

To discover how the state became so dry, and to learn how recent snowfall fits into the picture, KRQE News 13 analyzed the data and spoke with Richard Strait. He’s the State Soil Scientist, and he helps put together reports on water — or the lack thereof — in New Mexico.

“There’s a lot of factors behind how we got to where we are today,” Strait says. For one, “we had an exceptionally weak monsoon season last summer.”

The North American Monsoon runs each summer, typically forming around May and lasting through September. As a region of high pressure builds over the southeast corner of the state, moist air from the Gulf of Mexico and the Pacific swirls over New Mexico, bringing moisture during dramatic thunderstorms. But throughout the summer of 2020, the state saw below-average rainfall. While July saw near-average precipitation, June, August, and September were each well below average. In June, precipitation was about 60% below average, according to data from the National Oceanic and Atmospheric Administration. In August, precipitation was 71% below average and in September, 52% below average.

Last year’s monsoon brought below average precipitation, contributing to New Mexico’s drought. Data from NOAA National Centers for Environmental Information.

The weak monsoon meant that we went into winter with particularly dry soil across the state, Strait says. Then, when the winter snow finally fell, that dry soil acted like a sponge, soaking up the moisture and leaving less water available to become snowmelt runoff. And on top of that, snowfall was relatively light across the state this winter, Strait adds.

Snow, as measured by the amount of water stored in the snowpack, is important because that’s where we get most of the water we use, Strait says. Although we also rely on underground aquifers, when it comes to snow, “the more we have,” he explains, “the greater our water supply.” And this year, the snow supply is roughly normal in some mountains, but extremely low in others.

“We’re in an interesting snowpack situation this year,” Strait says. “In the Rio Grande Headwaters, which is predominantly in Colorado, but reaches down into New Mexico,” Strait explains, “we’ve seen some decent snow this winter.” That basin’s snowpack is at 96% of the median, according to the March 2021 New Mexico Basin Outlook Report. That may sound good, but Strait points out that the numbers mean the Rio Grande Headwater snowpack is basically normal — and in New Mexico, normal means dry.

Further south, the snowpack decreases drastically. In the Rio Hondo basin, which ranges from Roswell to the Sacramento Mountains, snowpack is only at 3% of the median, according to the Basin Report. So across the state, the snowpack ranges from “just barely OK to really not so great,” Strait says.

Drought conditions spread across New Mexico beginning in the spring of 2020. Now, more than half of the state has reached the most severe level of drought. Maps and data from the US Drought Monitor.

The end result is that, as of mid-March, about 54% of the state is experiencing “exceptional drought.” In that category, the state may see “exceptional and widespread crop/pasture losses” and “shortages of water in reservoirs, streams, and wells creating water emergencies,” according to the US Drought Monitor.

In New Mexico, “drought periods are somewhat cyclic,” Strait says. They tend to appear every 10 to 15 years or so. Since 2000, there have been several periods of intense drought, but during the most current drought, more land has been under the “exceptional” category than at any time in the last 20 years. And recent snow doesn’t mean the drought is over.

New Mexico’s droughts are cyclical, but the current drought is the most severe over the last few decades. Data from the US Drought Monitor.

“One snowstorm helps us a little bit in the short term, but the drought situation is more of a long term condition,” he says. And the fact that this is a spring snowstorm means that we may actually lose some of the freshly-fallen moisture to the atmosphere right after it falls.

With spring storms, “what we often see is that the snow is followed by some warmer, windier days,” Strait says. “And that’s currently in the forecast.” The wind and heat can quickly sublimate the snow, turning it into water vapor before it can help moisturize the ground.

“That’s another thing that is kind of a challenge for us to overcome,” Strait says. “We’re going to see a significant amount of that moisture that’s just lost to the atmosphere.”

In the end, “we are getting some snow where it matters, up in the mountains, so that does contribute to our water supply,” he says, but any moisture that sticks around from a single storm isn’t likely to pull us out of this drought.