Is the drought lightening?
Photo courtesy Mitzi Thomas
It's rare to see a fourth year of La Niña. So as we close out on year three, let's look at what that could mean for the Brazos River basin.
Texas State Climatologist John Nielsen-Gammon says the weather could go either way. "If you want to be optimistic, it doesn't take much to get a large amount of precipitation during October, so there's still room to improve this drought, Nielsen-Gammon said. "And, looking longer-term, we've never seen a fourth year of La Niña, so cross your fingers."
With La Niña conditions forecasted for this fall and winter, drought is expected to increase in the coming months. Aaron Abel, BRA Water Services Manager says, "Below normal rainfall and above normal temperatures have been the case over the last month. October is typically our second wettest month of the year for the Brazos River basin in terms of monthly rainfall."
What is La Niña?
La Niña is a weather pattern that occurs in the Pacific Ocean every few years. In a normal year, winds along the equator push warm water westward. Warm water at the surface of the ocean blows from South America to Indonesia. As the warm water moves west, cold water from the deep rises to the surface. This cold water ends up on the coast of South America.
La Niña tends to increase Atlantic hurricane season activity. Winters tend to be drier through the southern tier of the US and can lead to or intensify drought conditions, according to the National Oceanic and Atmospheric Administration (NOAA). They are even linked to more frequent spring hailstorms and tornadoes in the south-central US.
This summer, some areas of Texas saw extreme high temperatures, with many consecutive days over 100 degrees. In late August, large portions of the state received much-needed rainfall, enough to cause some counties to lift their burn bans.
More than 90% of the Brazos River basin has been under some form of drought conditions since December 2021, according to the U.S. Drought Monitor. In June, the basin hit 100% drought conditions, dropping to 99% only once. More counties are reinstating their burn bans due to the drying conditions.
Abel also noted, "After the above normal rainfall in late August to early September, some locations within the basin and in Texas have not seen measurable rainfall in over 30 days, and we have continued to see requests for downstream water supply for many of our customers downstream of the reservoirs within the system."
But could fall showers push us out of drought conditions, or is the drought likely to continue?
Nielsen-Gammon says, "La Niña has at least a few more months before it runs its course. According to the Climate Prediction Center, it will almost certainly last through the end of the year and probably survive into the spring."
"Typically, this means a warm and dry winter is favored," he said. Warm is a good bet since temperatures are increasing. In 2020-2021, it wasn't all that dry, but 2021-2022 certainly was, and either sort of winter is possible for 2022-2023."
Nielsen-Gammon reminds us, "Also worth mentioning is that La Niña seems to make occasional extreme cold more likely too, as you might have noticed over the past couple of winters."
Remember the great Texas freeze of 2020?
Though drought conditions may persist, the reservoir system is functioning as planned. "Overall, the BRA water supply system is approximately 73 percent full, and the system continues to operate as intended. The reservoirs throughout the system captured the needed water during the wetter times, primarily last year, to be used during this dry year and have successfully met the needs of our customers throughout the basin."