DALLAS — Severe storms moved in to North Texas from Oklahoma late Monday night into early Tuesday morning.
What is a bow echo?
As the cluster of storms moved into Denton County, it started "bowing" on radar. This is called a bow echo and it is a type of radar signature associated with strong thunderstorm wind gusts. The name comes from the shape of the leading edge of the storm. It takes on a concave shape resembling a "bow" or a "backward C." This signature is associated with strong winds, heavy rain, large hail and even brief, weak tornadoes.
Why did this happen?
The atmosphere over North Texas early Tuesday morning caused incoming storms to produce high winds.
Moisture - The extremely muggy air fueled the thunderstorms with dew points in the upper 70s. Thunderstorms that produce high winds and heavy rainfall thrive in high-moisture environments. High moisture leads to high rainfall rates, causing an abundant amount of rain-cooled air that then falls out of the storms.
Instability - Our atmosphere had a lot of energy to work with. The current pattern that North Texas is in keeps instability high. This is noted not just by the humid air, but also the heat. Sunday's high was 98 (hottest day of the year so far) and Monday's high was 96. This extreme instability caused storms to reach 60,000 feet Tuesday morning. For some perspective, airplanes fly at 30,000 to 40,000 feet.
Inflow - 40 mph wind speeds were reported in this storm's inflow. Inflow is wind that goes into the storm to help it grow. Strong inflows are associated with tall, strong, and long-lived thunderstorms. In this particular case, it is likely the reason why the thunderstorm was able to "bow out" for the length of several counties in addition to sparking tornado warnings lasting a couple of hours.
Straight-line winds were behind much of the damage and power outages across the metroplex Tuesday morning. The highest wind speed recorded (so far) is 95 mph in The Colony. Many areas across Dallas county reported wind gusts of over 70 mph.
