The trick is to smoke the meat and not make the meat smoke

Dark Sky - A COOL Weather App

First Image
This blog post is about an amazing weather app for the iPhone, iPod + and iPad called Dark Sky. This amazing app was a Kickstarter project where normal people like you and me pledge money via a web site to help fund interesting projects. At first blush what this app does seems truly amazing, but when you think about it a little bit more it all makes sense. Dark Sky attempts to predict rain or snow for the next hour down to the minute. It is not a general purpose weather app with temperature, relative humidity, wind direction and all the other bells and whistles. Dark Sky is intended to supplement these full fledged weather apps and provide highly accurate information about what to expect in terms of precipitation in the next hour. Where our hobby involves cooking outdoors I think you’ll realize right away the value of knowing if and when it is going to rain or snow in the next hour.

If all of this seems to good to be true let me explain how it works. There are over 140 Doppler radar sites around the United States run by NOAA (The National Oceanographic & Atmospheric Administration). These radar stations are required by law to make their data available to the public. Dark Sky mines this data to perform it’s magic. It uses the data to extrapolate the direction and velocity of the storms tracked on radar and will project that 1 hour into the future. While weather is highly volatile and unpredictable over time, it is far more predictable in short slices of time. By limiting the prediction time to the next hour it can be highly accurate down to the minute. The app can also give you a more general prediction for the next 6 hours or so. So on the surface what seems like magic at first, is really not as difficult as it appears.


The user interface for the app has two components. A weather radar map and a sliding timeline bar graph at the bottom of the page. When you first launch the app it finds your location via the GPS chip in your phone. It then pulls up a weather radar map with your location centered on the map. Along the bottom of the map the bar graph shows a time line along the horizontal axis in 10 minute intervals for the next hour. If there is any precipitation occurring currently or that will occur in the next hour the graph shows a yellow curve whose height along the vertical axis represents the intensity of the rain. You can move a slider along the graph to move forward or backwards in time. As you move forward or backward in time the radar plot changes to show what it looked like or will look like at that point in time. Below the graph is a grey status bar with a readout of the current temperature and whether it is raining at this minute. At the other end of this grey bar is a prediction of whether it will be raining one hour from now. The space in between is used for status updates. The first day I had the app I was racing to get home before some severe thunderstorms arrived. As I pulled into my driveway it was just starting to spritz and Dark Sky said “It should be starting to rain”. So far it has been highly accurate: When it says it will start raining in 5 minutes, you can pretty much bet on it plus or minus a minute or so. It is 8:00 AM as I write this. Flicking the grey bar to the right shows rain predictions for the Next 3 hours, This Afternoon, This Evening and Overnight. These predictions aren’t meant to be as accurate as those for the next hour. The app authors say under certain worst case conditions the accuracy might be closer to 15 minutes, but still that ain’t too shabby.


I mentioned the weather radar map earlier. It has several features unique to Dark Sky. The first feature is it the weather radar image of the precipitation is cleaner and more accurate than traditional doppler radar images. The app’s authors spent a great deal of time working on algorithms to help clean up the clutter found in most radar images. What you are left with gives you a more accurate view of where the precipitation is. Doppler radar stations in the US take their images in 5 minute intervals. This sometimes results in a jerky appearance when the images are strung together and set into motion. Sometimes this herky jerky motion makes it hard for someone (particularly a novice) to tell the actual direction of the storm. Once again the app’s authors have created algorithms to allow them to create the in-between frames, thus giving you a smooth animation unlike any you’ve seen before. I mentioned earlier you can scrub backwards through the time line. The radar image will move backwards through time as well and goes back farther than the traditional doppler radar feeds in other weather apps. The apps authors also track the accuracy of their predictions and interpolated Doppler radar images and tweak their programs to insure even greater accuracy in the future.

Dark Sky is a universal app that is customized for both the iPad and the iPhone or iPod +. So far I’ve used it mostly on my iPad, but think how handy it would be to have an app that will accurately predict precipitation for the next hour when you’re out and about. On the smaller screen of the iPhone the radar takes up the entire screen and the bar graph and prediction data get their own screen. I’ve had Dark Skies on my iPad 3 for over a month now and it has been amazingly accurate within it’s one hour time window. Right now the app is available in the US only and it is only available at this time for iOS devices. There are Kickstarter projects online to raise funding to create an Android version as well as versions for other countries besides the US. The cost is $3.99 and is worth every penny.


  DARK SKY DEVELOPER’S BLOG PAGE - Here is the link to a Blog page by the developers of Dark Sky explaining how Dark Sky works.
  DARK SKY KICKSTARTER PAGE - Here is the link to the Kickstarter Page where you can find out more about how this App works it’s magic.
  DARK SKY APP PAGE - Here is the link to the Dark Sky page in the IOS APP Store.


blog comments powered by Disqus