A record-breaking, triple-digit wind gust roared through part of Texas on Tuesday, but it wasn’t from a tornado or a hurricane.
An airport weather station in Midland, Texas, recorded a wind gust of 111 mph Tuesday evening – the first triple-digit gust in its 94-year-history in weather reporting. It shattered the previous record of 97 mph set on June 26, 2007.
The culprit? A “dry microburst associated virga bomb,” according to the National Weather Service.
That’s the technical way to say the atmosphere just threw a knockout punch.
To explain what a dry microburst virga bomb really is, we need to zoom out a bit. Microbursts fall under the umbrella of a phenomenon called downbursts, which are strong wind events that develop because of how air moves up and down in thunderstorms.
Thunderstorms are fueled by an updraft of warm, rising air. Eventually, some of that air cools, forms precipitation and then a combination of wind and precipitation rushes to the ground in a downdraft.
A downburst takes what a typical downdraft produces and cranks it to the extreme.
Picture yourself dumping a bucket full of water directly onto the ground: It hits hard and splashes out from the center.
Downbursts do just that, but with powerful winds that then move outward at high speeds. The strong winds typically last 5 to 10 minutes at most but can exceed 100 mph in the most extreme cases. Microbursts are downbursts that are less than 2.5 miles wide.
Downbursts are typically either wet – precipitation and wind reach the ground – or dry – just wind reaches the ground. Texas’ microburst was dry.
As for the “virga bomb” part of the NWS report – that’s just a punchy way to say it was an impressively strong dry microburst. Virga is precipitation that falls from clouds but evaporates before it reaches the ground.
Downbursts occur fairly frequently in powerful thunderstorms, but one this extreme is rare. Downbursts become more powerful when they move through a layer of drier air near the ground, as Tuesday’s did. Dry air evaporates precipitation in the downburst at the last second, which actually cools the surrounding air and makes it heavier. Heavier air hits the ground harder, producing stronger winds.
Tuesday’s 111 mph gust courtesy of that virga bomb would have been more at home in a hurricane than a random thunderstorm. Category 2 hurricanes, for example, have sustained winds of 96 to 110 mph but often produce gusts stronger than that range.
The strongest wind gust ever recorded in Texas stands at 180 mph and was produced by Hurricane Celia in August 1970, according to the state’s climatology office.
The hurricane-strength gusts from the fierce virga bomb did not damage Midland’s airport, but did break several power poles and knock over a semi-truck in nearby Odessa, according to the NWS.
Other thunderstorms in the same area also produced strong winds that kicked up dangerous dust storms.
CNN Meteorologist Monica Garrett contributed to this report.