Why is fire danger so high this year in San Antonio and the Hill Country?

Multi-year drought and La Niña play key roles

If you’ve been paying attention to the weather recently, it seems like nearly every other day we’re dealing with Red Flag Warnings, high fire danger, gusty winds and dry weather.

We’ve had blowing dust and smoke, and devastating fires like the Crabapple Fire and Duke Fire.

So, what’s the deal? Why is fire danger so much higher this year? Here’s what you need to know:

Key Points:

• A weak La Niña is ongoing, and La Niña tends to make our weather pattern drier and windier.
• We’re in the middle of a multi-year drought, which increases fire danger.

La Niña

When you look at the top five years for wildfire damage in Texas, the years have one thing in common: they were La Niña years.

La Niña is a complex weather pattern that results from cooler-than-average water in the Pacific Ocean. But why does La Niña raise the fire risk in Texas?

The answer is twofold: La Niña shifts weather patterns north and tends to strengthen winds.

LA NIÑA SHIFTS WEATHER PATTERNS NORTH

La Niña has a big impact on the jet stream, which is a fast-moving current of air that creates storm systems.

During a normal year, the jet stream positions itself in such a way as to give us the usual amount of rainfall. On the other hand — during a La Niña year — the jet stream is pushed northward, taking healthy rain with it, and leaving South Central Texas drier than average.

Without healthy rains, vegetation is left to dry out, creating fuels for potential brush fires. The wildfire risk increases significantly.

LA NIÑA STRENGTHENS WINDS

In addition to shifting the jet stream north, La Niña also amplifies the jet stream which strengthens low-pressure systems. A stronger low-pressure system means stronger winds, and stronger winds greatly increase the risk of grass fires.

Multi-year Drought

Drought has a huge impact on wildfire risk. When we don’t receive rain, vegetation dries out, and the dry vegetation fuels grassfires.

Believe it or not, the last time South Central Texas was drought-free was in late 2021/early 2022. That means we’ve been in a continual drought for three years.

Drought has a nasty habit of making itself worse before it gets better. That’s because drought often creates a feedback loop: dry soil means there’s less evaporation than normal. With less evaporation, rain can’t form as easily. And when it doesn’t rain, soils dry out. This starts the cycle over again, and the loop just continues repeating itself, making drought worse.

WHEN WILL DROUGHT END?

Unfortunately, it’s impossible to know when exactly South Central Texas’s multi-year drought will end. But what we do know is that it would take A LOT of rain to end the drought.

According to the National Centers for Environmental Information, we would need 20 to 27 inches of rainfall to eliminate drought within the next six months. Needless to say, that’s much more rain than normal. It will likely take a flooding event to help with drought conditions. And, if you’ve been in San Antonio long enough, you know that our intense droughts usually end with big floods.

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