Dry lightning concerns in current drought, fire conditions

AUSTIN, Texas - Central Texas desperately needs rain, but as dangerous fire conditions continue, storms brings another threat: dry lightning. 

This time of year a thunderstorm is great as it cools things down, it brings rain, and they just look pretty, but those same storms can produce wildfires. That's because the lightning that comes from the storms can strike well outside the rain footprint. If that happens anything flammable can be set ablaze.

It's a common occurrence in areas that typically see wildfires more often. In 2020 lightning sparked about 650 individual wildfires in California that ended up consuming nearly 4,000 square miles of forest.  That's nearly the same size as the entire Austin metro area, from San Marcos to Georgetown and west through all of Lake Travis.  

This year with the drought and fire conditions being so bad, the risk of dry lightning thunderstorms is very real.

Thunderstorms bring two major threats when starting a fire: lightning and wind. Lightning can strike upwards of 10 miles away from the rain-core of the storm. That means the lightning is probably striking something that's very dry and won't get any rain. 

The second threat is winds generated often by the same storm. Those winds can fan flames very quickly and, in some cases, help spread fires that do start by blowing embers farther away into unburned dry fuels.

Thunderstorm winds can spark wildfires other ways too. If a BBQ smoker or charcoal grill is blown over by the winds, fires can spread very quickly. The same can happen to camp or bonfires or burn piles if they can't be extinguished in time.

Thunderstorm winds from even sub-severe storms can reach 50 miles per hour, which will easily fan any flames that get out of control.

A complicating factor is that lightning fires may not start immediately. Lightning can start a tree, log or area brush smoldering for a long time before anything catches. That process can take up to two days before anything bad happens, which makes it important to keep an eye out for any smoke plumes that occur after thunderstorms move through.