outlook+water: La Nada through March? drought shrinks, and rain bombs in the Hill Country

SUMMARY:

• Drought conditions (D1–D4) decreased to 30% of the state from 39% of the state four weeks ago (and is surely lower after the early July rain bombs); statewide reservoir storage increased to 80% full up from 78% four weeks ago, about 4 percentage points below normal for this time of year.
• The El Niño Southern Oscillation remains in neutral conditions, which are favored through March.
• The recent rains in the Hill Country are not as rare as you might think.

I wrote this article on July 6, 2025

When I am interviewed during droughts and asked, “what would end a drought,” I generally mention a “mellow tropical system.” But what happened from July 3 through 5 was not a mellow tropical system.

So, what happened? According to The Weather Channel, this was a collision of an upper-level disturbance from West Texas carrying deep moisture, the moist remnants of Tropical Storm Barry from the Pacific, and a low-level jet stream fire-hosing moisture straight into the Hill Country. The results were devastating, resulting in epic rainfall totals exceeding 20 inches in places with more than 500 square miles stretching from San Angelo to Brady to Kerrville to Georgetown to Austin and receiving more than 8 inches of rain (Figure 1). Heartbreakingly, more than 80 people have died, with about 40 still unaccounted for, including many little girls at Camp Mystic on an upper reach of the Guadalupe River.

We will see substantial rises in area reservoirs, some of which will end the water-supply droughts we have been suffering, but these rises seem shameful given the death and destruction that came with them. This event (Barry+?) shows the difficulty in predicting such severe weather, in warning people about what is coming, people receiving these warnings, and people taking these warnings seriously. There will be a lot of hashing and rehashing, inquiring and testifying, and thinking and rethinking about what we can do better to prevent these tragedies in the future.

According to the National Weather Service, this storm is the 20^th tropical system to drop 15 or more inches across the Texas interior (suggesting a 5.5-year recurrence interval for these storms). Barry+ continues the pattern of major droughts ending with major floods. Hopefully, there is something major we can do to protect people during future events.

June showers showered most of the eastern and northern parts of the state with four or more inches of rain (Figure 2a). The percent-of-normal map looks similar to the rainfall map, with many counties getting more than their monthly average allocation, but those west of the Big Bend area, west of Pecos, are coming up short (Figure 2b).

The amount of the state under drought conditions (D1–D4) decreased from 39% four weeks ago to 30% today (Figure 3a), with improvements throughout the state (Figure 3b). Extreme drought or worse decreased from 22% of the state four weeks ago to 13% today, with exceptional drought decreasing from 14% to 6% (Figure 3a). In all, 38% of the state is abnormally dry or worse (D0–D4; Figure 3a), down from 48% four weeks ago.

The North American Drought Monitor, which runs a month behind current conditions, shows drought in the Southwest, with smatterings in the northern part of the continent (Figure 4a). The Rio Conchos basin in Mexico, which confluences with the Rio Grande just above Presidio and hosts the largest tributary to the Lower Rio Grande, remains in extreme to exceptional drought (Figure 4a).

Conservation storage in Elephant Butte Reservoir—an important source of water for the El Paso area—decreased from 13.0% full four weeks ago to 6.0% more recently (Figure 4b), about 10 percentage points below a rather pitiful median storage of 25% full.

Combined conservation storage in the Amistad and Falcon reservoirs increased to 23.7% full from 22.0% four weeks ago and is almost 40 percentage points below normal for this time of year (Figure 4c). Storage is on an increasing trend from recent rainfalls, so perhaps we’ll see more storage improvements over the next month.

Basins across the state have continued to experience flows below the historical 25^th, 10^th, and 5^th percentiles over the past week (Figure 5a). Statewide reservoir storage is at 79.5% full, up from 77.7% four weeks ago, but about 4 percentage points below normal for this time of year (Figure 5b). The abrupt uptick is due to the flooding in Central Texas and is expected to continue upwards. The reservoir marked in orange in the Dallas-Fort Worth area (the persimmon in a sea of blueberries) is New Terrell City Lake and has dropped from full in early March 2024 (Figure 5c). The Lake is no longer used for water supply and appears to be undergoing long-term maintenance work.

My (drumroll please) “Hydrograph of the Month” is O.H. Ivie Reservoir, which has also benefitted from the big rains that have fallen in Central Texas (Figure 5d).

We are under La Nada conditions with neither an El Niño nor La Niña imminent (Figure 6a). Neutral conditions are favored through the end of the year into 2026 by both the dynamical and statistical models (Figure 6a, b).

The U.S. Seasonal Drought Outlook through August shows drought persistence [but we know better!] (Figure 7a). The three-month temperature outlook projects (surprise, surprise) above-average temperatures for most of the state (Figure 7b), while the three-month precipitation outlook favors average rainfall [ummm…WRONG!!!] (Figure 7c).