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Earth from Orbit: Texas Dry Line Drives Storms

May 6, 2021

Severe thunderstorms struck Texas on May 3, 2021. The storms formed along a dry line—a boundary between moist and dry air. Dry lines are common in Texas in the spring and summer, when moist air from the Gulf of Mexico meets dry air from the Desert Southwest, often triggering thunderstorms.

NOAA’s GOES-16 (GOES East) and GOES-17 (GOES West) satellites tracked the storms in real time, providing vital information to forecasters. The GOES satellites are essential tools for assessing the threat of severe weather and keeping an eye on evolving storm conditions.

Some of the storms developed into supercells—storms that contain rotating updrafts—and produced widespread straight-line winds, hail, and reports of tornadoes. NOAA’s Storm Prediction Center tracked 23 tornado reports on May 3 , and the National Weather Service in Fort Worth confirmed an EF-2 tornado with estimated 130 mph wind speeds struck the town of Blum in northern Texas.

A variety of GOES-16 and GOES-17 imagery shows the severity of the storms. Visible imagery provides information about cloud properties, revealing the presence of overshooting tops, gravity waves, and above-anvil cirrus plumes, which indicate a storm may be severe.

Infrared imagery provides information on the temperature of the cloud tops. The colder the cloud top, the more likely the storm is producing heavy rain and severe weather. Combining visible and infrared data into one image is called “sandwich” imagery. The mix of visible data and temperature from infrared imagery helps identify key formations in a storm. Dark red areas are colder cloud tops, which indicate areas of greater storm intensity.

GOES-16 imagery also reveals significant lightning activity within the storms. Rapid increases in lightning activity often precede severe and tornadic thunderstorms.

When severe weather strikes, GOES-16 and GOES-17 keep a watchful eye to help identify intensifying storms and track rapidly changing weather conditions.