Weather Radar Picks Up Car Doing 130 MPH

Illustration for article titled Weather Radar Picks Up Car Doing 130 MPH

An atmospheric phenomenon this morning allowed the Doppler weather radar in the Chicago area to pick up cars driving down a pair of interstate highways, including one vehicle that appears to be doing 130 mph. Weather radar isn't that dissimilar from what cops use to bust speeders, as both project beams to gauge the speed of something moving away from a point. Typically, the radar is measuring the density of droplets of water in clouds, but a layer of warm air in the atmosphere deflected the weather radar's beams towards the road. So how did they know how fast the car was going?


The weather service office in Chicago shared two images that clearly show clumps of traffic along I-55 and I-57 in North Central Illinois. The first image is the typical green-to-red scale radar image that measures the density of rain in a cloud, which is how the weather service knows how large a storm is. The second measures the direction of those rain drops (either towards the radar site or away from it) and the speed they're traveling. This is how they often detect tornadoes.

Illustration for article titled Weather Radar Picks Up Car Doing 130 MPH

Using the scale above, you can see that a car near Danforth, Illinois is dark blue, which corresponds to 115 knots or 130 mph. They appear to be heading away from Chicago which means this is noise in the radar, someone left something important at home or it's the Blues Brothers. It's probably a good thing the weather service can't write tickets. [National Weather Service - Romeoville, IL]


LandofMinos: ...sent down to strike the unroadworthy!

That sorta reminds me of that story getting around the internets lately

I'll let cut n' paste tell the story...

...Two British traffic patrol officers from North Berwick were involved in an unusual incident, while checking for speeding motorists on the A-1 Great North Road .

One of the officers (who are not named) used a hand-held radar device to check the speed of a vehicle approaching over the crest of a hill, and was surprised when the speed was recorded at over 300mph. The machine then stopped working and the officers were not able to reset it.

The radar had in fact latched on to a NATO Tornado fighter jet over the North Sea , which was engaged in a low-flying exercise over the Border district.

Back at police headquarters the chief constable fired off a stiff complaint to the RAF Liaison office.

Back came the reply in true laconic RAF style. 'Thank you for your message, which allows us to complete the file on this incident. You may be interested to know that the tactical computer in the Tornado had automatically locked on to your 'hostile radar equipment' and sent a jamming signal back to it. Furthermore, the Sidewinder Air-to-ground missiles aboard the fully-armed aircraft had also locked on to the target. Fortunately the Dutch pilot flying the Tornado responded to the missile status alert intelligently and was able to override the automatic protection system before the missile was launched'.