Do you get your weather from a weather app? The number of weather apps available for smartphones and tablets grows by the day, but they're not all equal. Your weather app likely sucks—in fact, some apps are so wrong that you're better off looking out the window. Here's how to remedy the situation.

Opening Day brought about the latest installment of a sports team stepping in it when it comes to the weather. Late last year, Patriots head coach Bill Belichick said that meteorologists are "almost always wrong," prompting a snarky outcry from meteorologists around the country. Well, baseball managed to top that one. The Miami Marlins made fools of themselves yesterday, allowing their home opener to suffer from a rain delay even though the stadium has a retractable roof.


Barry Jackson, a sports reporter for the Miami Herald, reported that three executives were unaware of the impending rain because their weather apps didn't say that it would rain. Now, it's reasonable to think that a baseball team could afford to pay a meteorologist to do some freelance consulting work to tell them, hey, y'know, there's a storm heading towards the stadium, so you should probably close the roof. Even looking at the radar yourself isn't the best solution—if you don't know what to look for, you might miss a developing storm or one that's changing direction to come towards you.

The Marlins learned a tough lesson yesterday—not all weather apps are equal. Many of those off-brand, pretty-looking weather apps people flock to download use the same forecast process as those middle and high school "weather weenies" I talked about yesterday; in other words, these apps take data straight from the weather models and display them on your phone as a forecast.

Quality weather forecasts are created by trained forecasters who use their knowledge and experience to complement model data. Hell, if we were to use straight weather model data all the time, there would be busted forecasts of crippling blizzards every few days for six months of the year, and the other six months would be dominated by forecasts of non-existent category five hurricanes pummeling the coast like an apocalyptic movie. That doesn't begin to mention all of the ugly temperature/precipitation surprises we would encounter.

This kind of data is freely available to anyone who wants it. Here's a link to the GFS MOS, which is the American global model's "model output statistics." Below is a screenshot of the GFS MOS from this morning's run of the model for D.C.'s National Airport:

Look at that, you've got temperatures, dew point, cloud cover, wind speed and direction, probability of precipitation, precipitation type, accumulated precipitation, visibility, ceilings, and a few other variables. It looks like a forecast!, and it's this data to which meteorologists add value when they create their own forecasts.

Here's a good example of meteorologists disagreeing with the model data: the same run of the same model shows a high temperature of 79°F in Danville, Virginia, tomorrow. The National Weather Service predicts a slightly lower high at 77°F, while The Weather Channel bumps it up to 85°F. Both the NWS and TWC expect clouds to clear out enough to allow the sunlight to heat up the surface, but they disagree on the wind speeds. The NWS expects calm winds in Danville, while TWC shows winds from the southwest at 5 to 10 MPH—enough, it seems, to bump temperatures up to the mid-80s.

Right or wrong, it's this kind of nuance that derives from the forecaster's knowledge and experience, which is something that lacks in most weather apps. This absence of human intervention leads to wildly inaccurate weather information reaching the end user, which is detrimental whether you're simply going to the park or in charge of operating the roof at a baseball stadium in southern Florida.

Some weather apps are top-notch. Like 'em or hate 'em, The Weather Channel's forecasts are among the best in the business, so the Weather Channel app (and the Wunderground app, which uses identical forecasts since Wunderground is owned by TWC) is a pretty good bet. The National Weather Service doesn't have a mobile app (yet!), but you can save your city's forecast page as an icon on your home screen, allowing you to tap the icon and open your browser straight to the NWS forecast page.

Many other apps produced by known entities like AccuWeather, WeatherBug, and local news stations also produce acceptable forecasts that you know are quality controlled. While its forecast quality relative to other outlets is debatable, the DarkSky app is immensely popular for its "nowcasting" feature that uses radar data to tell you exactly how long it'll take for approaching precipitation to reach your location.

Do some research about the app you're downloading to your phone. If it's developed by a a person or company you've never heard of and can't find much about, you should take its forecasts with a grain of salt and consult the experts instead. Using bad data from bad apps will leave you out in the rain.

[Images: AP, NWS]

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