Fort Worth

CASA radars provide a new set of eyes on DFW’s severe storms

There’s no telling if the newest CASA radar would have helped see the tornado that formed Thursday in north Fort Worth — but the extra set of eyes certainly couldn’t have hurt.

If it had been operational Thursday, North Texas’ sixth CASA, short for Collaborative Adaptive Sensing of the Atmosphere, would have been the closest radar to where the tornado touched down.

“We don’t know if it would have helped, but theoretically it might have allowed us to see something sooner,” said Tom Bradshaw, meteorologist in charge at the National Weather Service Forecast Office in Fort Worth.

As it turned out, forecasters didn’t know about Thursday’s tornado until one of their own forecasters alerted them on his way home from work.

“We had this storm going on a 3.9-mile path, some of which was very close to I-35W,” Bradshaw said. “It would have been great if someone had called 911. We got a tornado warning out as soon as we were alerted, but by that time the tornado had already lifted.”

The network of CASA radars may help.

The one installed Friday along Boat Club Road in northwest Fort Worth adds to the radars that are forming a growing network around the Metroplex. Others have already been installed at the University of Texas at Arlington, Cleburne, UNT Discovery Park in Denton, Addison and Midlothian.

All of these radars work as a network to give forecasters more than one view of a storm.

The CASA radars aren’t as powerful as the NEXRAD (next generation) radars that the weather service uses to see as far out as 150 miles.

Instead, the CASA radars have a 25-mile radius and look into the lower levels of the storm, below 32,000 feet, where much of the damaging parts of the storm take place. CASA’s network can refresh the image every 30 to 60 seconds versus up to 5 minutes for NEXRAD radars.

“The majority of damage happens in the lower portion of the storm,” said Juan Ortiz, Fort Worth’s emergency management coordinator. “For once we'll be able to see a high-resolution image. We'll have a better view of what is happening.”

The DFW CASA network is the first of its kind in the nation.

The first eight radars, which cost about $750,000 each, were donated. The two remaining radars are expected to be installed in Mesquite and near McKinney.

Local entities pay for the installation cost. Fort Worth paid about $100,000 for Friday’s installation.

The North Texas Council of Governments oversees the network, and member cities and counties help pay for the network.

Eventually, the council of governments hopes to expand the network to 16 sites, and muncipalities from the Red River to Waco have inquired about participating.

Bradshaw, the National Weather Service meteorologist, said they are still learning how to incorporate the network. But as more radars are installed, it should help improve warnings.

It isn’t just spotting tornadoes. The radar network should help track rainfall rates and may give earlier warnings to flash flooding, allowing cities to block off flood-prone areas.

“We have really been waiting for this radar with its location since it allows us to see storms coming out of Parker and Wise counties,” Bradshaw said. “And we may learn more as these storms pass the sites and move into the network, where they can be seen by multiple CASA radars.”

Bill Hanna: 817-390-7698, @fwhanna