Water + Weather for September 2024

Transcript

Dr. Mark Wentzel - Hydrologist, Texas Water Development Board

Hi everyone, and welcome to the Texas Water Development Board's latest Water and Weather report. I'm Dr. Mark Wentzel, a hydrologist in the Surface Water Division here at the agency. And today, we'll be taking a look at conditions for our state at the end of September.

Let's take a look at some of the big water and weather headlines. September rainfall and temperature were about normal, but conditions varied widely across the state. Large areas of West, East, and North Texas were drier and hotter than normal. At the end of September, 33 percent of the state was in drought, down 15 percentage points since the end of August. Statewide, storage in our water supply reservoirs was almost 74 percent of capacity, eight percentage points better than last year, but still about six percentage points below normal. In the next few months, drought is expected to expand in the Panhandle and North and East Texas.

Let's take a closer look at temperature and precipitation. On these maps, we're looking at both parameters relative to what is considered normal for September. From a water supply perspective, reds, oranges, and yellows mean trouble on both maps. They show areas with above-average temperature on the left and below-average precipitation on the right. September temperatures were at least one degree warmer than normal for most of the Panhandle and South and West Texas. Precipitation varied considerably, with large areas of Central Texas and other scattered areas getting twice their normal rainfall, while parts of East, West, and North Texas got less than 25 percent of normal.

Drought contracted 15 percentage points from the end of August, making this September the best for drought improvement since 2020 and the seventh best in the last 25 years. Even so, the Drought Monitor map for conditions as of September 24 shows 33 percent of the state in drought, the tan, orange, and red colors, and about another third of the state abnormally dry, the yellow area on the maps. These yellow areas are vulnerable to slipping into drought in coming weeks.

Let's take a look at how our surface water supplies were impacted in September. The dark line on this chart shows how storage in our water supply reservoirs this year compares to minimum, maximum, and median values for the day of the year from data going back to 1990. Also displayed are lighter lines that show how we did in 2023 and 2022, and a red line that shows how we did in 2011. Statewide, surface water supplies ended September at 73.7 percent of capacity, down only seven-tenths of a percentage point from the end of August. That's a relatively small decline for this time of year and, as a result, our statewide storage is now almost eight percentage points more than a year ago. Unfortunately, that's still about six percentage points lower than normal for this time of year.

What can we expect over the next few months? Sadly, there might not be a lot of good news for a while. Here's the latest seasonal drought outlook from the National Weather Service for conditions through the end of 2024. During that time, they expect drought expansion in the Panhandle and North and East Texas. La Nina conditions, above-average sea surface temperatures in the eastern Equatorial Pacific, are expected to develop and persist into the new year. Those conditions typically bring warmer and drier-than-normal winters to Texas, delaying drought recovery. That concludes our report. Until next time, I hope you all stay healthy and safe.