PowerDoppler 17 comin' atcha LIVE!

January 4, 2008 5:03 PM

Why does it seem like every local TV station has their own radar (usually with a ridiculously flashy name like MegaDoppler 3000)? Is it just for bragging rights or are they actually better/faster than the National Weather Service's radar?

One would hope/think that a governmental institution charged with keeping citizens safe would have equipment as good or better than a second-rate local TV station in a 100th-ranked media market.

Some things I've noticed, none of which really convince me that local stations need their own radar equipment:
- When I lived in semi-rural Missouri, a local station actually advertised that their radar dome was larger than the other stations', but their forecasts and the onscreen radar didn't look any better.
- I've also seen some stations advertising "high-def radar" but the images just seem like very zoomed-in, interpolated versions of the radar resolution I'm used to seeing.
- CBS 5 here in the Bay Area advertises that their radar is live, and that the other stations show radar data that is up to two minutes old. Is it because the other stations are actually using NWS radar instead?

posted by zsazsa to science & nature (6 comments total)

Actually, it's almost always NWS radar with a different presentation. It's hard to top the WSR-88D. There are some stations that run their own radar -- often old WSR-74C, using modern post processing, but almost all of them integrate real time data from the -88D radar network. Size of the radome is a bad measure -- indeed, running a larger dome than needed increases the chance the radar will be knocked out by high winds.

The real magic of modern radar isn't the transmitters, it's the computer processing. We've updated the -88D several times, and will continue to do so for a long while. It's possible -- and NWS is working on -- replacing the current mechanically scanned -88Ds with a new phased array transmitter, but that's several years in the future, at a minimum. Phased arrays would help the one problem with the -88D sets -- the time it takes to complete a full atmosphere scan, some 10 minutes in the most detailed mode, but this is really only critical in Tornado Alley.

How fast you get NWS updates depends simply on how much money you're willing to pay to get the data. NWS will offer the data up to realtime, but you have to pay for the data lines and implentation costs to get it. Indeed, they're required to -- NWS radar data is public domain, since it's generated with taxpayer money, and the data itself is free. The only cost is the network connections and such needed to get the data. If you want, you can download it off the net, and there are software packages available to integrate and redisplay the various datasets.
posted by eriko at 5:26 PM on January 4, 2008 [7 favorites]

Here's an example of a local station, WTNH. Read past the hyperbole, and their "Doppler network" combines 3 of the NWS radars with their local one. Having their own gives them some bragging rights, since there are no NWS ones located in CT, just NY and MA.
posted by smackfu at 6:04 PM on January 4, 2008

I wish I could find WCCO's current ad parodying this trend.
posted by mrbula at 7:58 PM on January 4, 2008

Sorry to hear you're still stuck with the Mega Doppler 3000 in Missouri. In LA we have the Live Mega Doppler 7000 HD (because the erratic weather in Los Angeles requires a state of the art storm tracker). Suck it! The weather promo commercials remind me of the commercials for monster truck shows--Sunday Sunday Sunday!

To answer your question, the info page I linked to mentions nothing about 7000. It's a one million-watt radar, which leads me to believe the name was pulled directly out of the station manager's ass.
posted by HotPatatta at 10:53 PM on January 4, 2008

I wonder about the "live feed" at KPIX. I don't think it's really live as they claim. It seems that much of it has as much to do with the physical presentation of the radar than anything else. The problem is that weather forecasting is just that: a prediction based on current satellite imagery. It's like the late 1990s trend of micro-climate forecasting. That was a huge mistake for stations, as it meant more data to explain to viewers who often didn't care to learn about a cloud formation traveling over Ross Valley. Even Accuweather (you have seen their logo on the TV news) uses NEXRAD but claims their proprietary algorithms delineate between rain and snow, where NWS does not. Whether that is actually a strategic advantage, I don't know.

As to Live Mega Doppler 7000 HD, that's just a marketing idea. I remember KOTI-TV in Medford, OR had the website Channel4000 for the longest time. It's just a way to show prowess. I like it best when they give their news helicopters names like "SkyMaster 7" or "NewsLeader 1" or "ActionAlert".
posted by parmanparman at 1:26 AM on January 5, 2008

The number is the channel number times a thousand (and in some markets, a million.)
posted by evilcolonel at 4:54 PM on January 6, 2008