This story has been updated.
NBCUniversal announced on Monday it is deploying mobile radar trucks for use by NBC-owned and Telemundo stations across the country. It might sound like the idea came straight off the PR desk, but there is science behind the concept — if conditions are just right and the radars are used properly.
The first “StormRanger” debuted Monday in Philadelphia for use up and down the Northeast Corridor, NBC said in a news release. Two more “will launch by the start of the Rio 2016 Olympic Games,” to markets in the central United States and the West Coast, the release stated.
The Dodge Ram trucks are equipped with an X-band dual-polarization radar. The wavelength is short (X-band), so it will produce high-resolution images; the waves are both horizontal and vertical (dual-pol), so the radar can tell the difference between rain, hail and snow.
The difference between these radars and the National Weather Service radars is the wavelength. NEXRAD radars have a longer wavelength, which means they produce lower-resolution imagery, but the radar beams travel much farther. The range on a NEXRAD is around 300 miles, while NBC’s radars will be able to see things only within 100 miles — under the best circumstances.
Josh Wurman, who leads the Center for Severe Weather Research in Boulder, Colo., is skeptical. He has been operating a fleet of mobile radars — the “Doppler on Wheels” — for 21 years and says X-band radars are great for research but probably not for hazard communication.
“In intense rain, an X-band radar attenuates a lot you won’t see through a squall line or a supercell,” Wurman told The Washington Post. “If you’re on the wrong side of the supercell, you’re not going to see the tornado.”
In hurricanes, they’re going to see “about two miles out. Maybe five,” Wurman added.
Mark Hunt, the director of technology programs for NBC-owned stations, told The Post that they are aware of the shortcomings of X-band radar, but were happy with the results in tests.
“We have consulted with researchers in the field, people in the educational industry,” Hunt said, “and it was demonstrated to our satisfaction that the technology was able to do what we needed to do.”
If the truck is in the right spot — not in a valley or with trees and hills blocking the view — it could be able to “see” precipitation and tornado debris closer to the ground, something NEXRAD cannot do. NEXRADs see only things high in the atmosphere — and there’s often a significant coverage gap below 10,000 feet, especially when the storm is very far away from the radar.
This can be a big problem for local TV stations who need to communication vital weather information to the communities that may fall into these gaps. “The reason this is so important is there are parts of our market that are under-served by the NEXRAD system,” said David Parkinson, a senior weather producer at NBC10 in Philadelphia.
The Philadelphia market has a few cities that are not totally covered by the National Weather Service radars. One of these locations is Morgantown, Pa., about 50 miles northwest of Philadelphia. On Tuesday, Parkinson had the opportunity to test the StormRanger on showers that were moving through the Morgantown area.
“The rain was five miles away, and [the result] was perfect,” Parkinson said.
But Wurman says getting the truck into the right position could prove be difficult, especially in heavy traffic or widespread severe weather. “The East Coast is going to be particularly challenging,” he said. “It’s very hard to find good spots to park the radars, that don’t have blockage like trees, houses, hills.”
Howard Bluestein, a professor of meteorology at the University of Oklahoma, also manages a mobile Doppler called the RaXPol. Bluestein’s high-resolution data helped the National Weather Service determine the El Reno, Okla., tornado in 2013 was the widest on record at 2.6 miles across.
“My guess is that they will be used mostly for entertainment and to interest viewers,” Bluestein said via email, “but they could be put to good use if they are sent to regions where the network of [NEXRAD] cannot ‘see’ what is happening at low altitudes.”
Bluestein also thinks NBC’s mobile radars might be useful for the research community, if NBC is scanning the storms in a useful way. And if they’re willing to share.
At the very least, we know these NBC trucks are going to have to be in the right place at the right time because of their small range. They might provide some useful data if they can catch a particularly dangerous storm, but that in itself is a challenge. It’s likely we’re going to see these trucks in promos more than in action.
“If I were advising them, I’d say ‘sure try it out,'” Wurman said. “We’ll have to see if this gives them a real value-add compared to a stationary radar.”
This post has been updated to include responses from NBCUniversal spokespeople, who were not available to The Post before this story was published.