Storms and record heat collide
A thunderstorm knocked out power to hundreds of Llano County residents on Wednesday, June 21, just one of many storms moving through the Highland Lakes during a days-long, excessive heat wave. The extreme temperatures could be contributing to storm development and an increased risk of tornados, hail, and lightning, according to weather watchers.
A peak of 1,386 power outages were reported across Llano County at about 7:45 p.m. Wednesday, according to county Emergency Management Coordinator Gilbert Bennett. The Central Texas Electric Cooperative outage map shows that number at two as of 2:30 p.m. Thursday.
The National Weather Service issued a tornado warning for the Kingsland area at 6:45 p.m. Wednesday, triggering the use of Llano County’s new outdoor warning system.
No major damage was reported, but 450 head of cattle escaped their enclosure onto Texas 29 during the storm, Bennett told DailyTrib.com, and wind gusts of up to 60 mph damaged trees in parts of the county. Some residents also reported half-dollar-size hail.
Burnet County was not as badly hit by the storm, said county Emergency Management Coordinator Derek Marchio.
“There were no reports of anything last night (in Burnet County) to my knowledge,” he said. “The worst of it really did happen in Llano County.”
Neither counties are escaping the extreme heat smothering Central Texas. The National Weather Service issued a heat advisory for the region through at least 9 p.m. Thursday. The heat index is expected to reach 112 degrees by mid-afternoon with actual temperatures topping 98 degrees.
Temperatures will remain high for the foreseeable future, breaking 100 degrees on Saturday and reaching 107 degrees on Monday, June 26. Triple-digits are expected through the Fourth of July weekend.
The National Weather Service uses Austin as a record-keeping baseline for Central Texas. The hottest day on record for June is June 26, 2012, at 109 degrees. July’s hottest day was 110 degrees, happening on both July 10, 2022, and July 23, 2018. The region’s two hottest days on record were Aug. 28, 2011, and Sept. 5, 2000, at 112 degrees.
High temperatures and humidity are major contributors to the development of thunderstorms, tornadoes, and hail, according to the NWS.
“In the summer, thunderstorms typically develop in the afternoon when the sun heats air near the ground,” reads a safety briefing from the service. “If the atmosphere is unstable, bubbles of warm air will rise and produce clouds, precipitation, and eventually lightning.”
The clouds formed by rising heat and moisture can quickly generate storms that have a chance of creating tornadoes under the right conditions.
“A tornado forms from a large thunderstorm,” the NWS reports. “Inside thunderclouds, warm, humid air rises, while cool air falls — along with rain or hail. These conditions can cause spinning air currents inside the cloud. Although the spinning currents start out horizontal, they can turn vertical and drop down from the cloud — becoming a tornado.”
As long as temperatures and humidity remain high, the Highland Lakes could be at risk for more severe storms in the near future.
Here are a few precautions from the American Red Cross to take during severe thunderstorms:
- Immediately get off elevated areas such as hills.
- Move away from ponds, lakes, and other bodies of water.
- Stay away from barbed-wire fences, power lines, or windmills.
- Never lie flat on the ground or shelter under a tree.
- If outdoors, seek shelter inside a sturdy building.
- Inside, seek shelter in an interior room on the lowest floor.
- Stay away from glass windows and doors.