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Curious what the weather models are showing for Denver in the coming week? Do you want to try to make your own forecasts? Now you can! We have been hard at work over the last few months creating, tweaking, expanding, and improving a comprehensive suite of weather forecast models, built entirely with Front Range Colorado in mind. They are now available on our site for your viewing pleasure. Continue for more information on how to access and best utilize them.

We began this project back in November when we realized that in order to make the best Front Range forecasts, we needed the best tools. While many other outlets offer a plethora of model content, several critical pieces were missing. For example, model data between 700 and 850 mb levels are rarely included, but are vital for locating Colorado cold fronts which are often very shallow. We also thought we could do better on the complex math and physics that are used to convert model precipitation into snowfall. Among other advantages, it’s always useful to have high-resolution visualizations zoomed right in on our state.

We have maps for the entire continental U.S (CONUS) and just Colorado

There are maps for the entire continental U.S (CONUS) and just Colorado

Our models have actually been available in some form for several months now, akin to a beta release. You may have noticed their inconspicuous appearance within the site’s navigation bar during the last few months, or some of the maps being used within our posts. Finally, we have now reached a point where they are fully-functional, feature-rich, and reliable. With that said, we welcome everyone to at least check them out and take advantage of them as you see fit. If that doesn’t interest you, that’s okay too! Everyone will reap the benefits by having access to our superb forecasts aided by these model products.

Currently available BoulderCAST model forecasts include: 

  • An extensive amount of GFS products to 144 hours
    • Full U.S.A. and Colorado only
  • NAM products to 84 hours (max)
    • Full U.S.A. and Colorado only
  • A limited selection of GEFS products to 120 hours
    • Some full U.S.A. maps
    • Plumes for precipitation and temperature
  • GFS and NAM meteograms


To access the models, head to the Forecast Models tab in the Navigation Bar from any page on our site.


From the drop-down menu, you can select which model group you want to jump to first.

Let’s say you select “GFS”. The model viewer will load up, like the image below.  This viewer is the interface for browsing all of the our model products.



You can use the Model Animation Controls at the top of the page to automatically loop the model forecast into the future with the Play button, or move back and forward one time step with the Previous Hour and Next Hour buttons. Below those controls are the Forecast Hours, in this case, from 0 to 144 hours in 6-hour increments. Hover over a given hour to display that specific forecast map.

To change model products from your current one, there are two options:

  1. In the menu on the left, click a specific model to expand a menu for each. Clicking “GFS Model” will expand a listing of available GFS products, for both the CONUS (continental U.S.) and Colorado only domains. Notice the expanded menu below. Click any model product in the list to load it into the model viewer.
  2. BoulderCAST_model_viewer_expanded Select from a listing of our most frequented model products using the navigation bar at the top of the page. From the drop-down listing, pick your desired forecast model product. In the example below, the NAM model drop-down is displayed.
Finally another snowfall recap!


If at any point you want a bigger view of the model map, click the hamburger button (three stacked dashes) in the top left corner to toggle the menu off on the left side of the page (it can be toggled back on too). This will increase the size of the map and move the hover controls to the right.


That’s it! Pretty simple and seamless to navigate between the different model products!

Look for updates and improvements to the current products, and even more additions in the somewhat near-future. For now, we think you will particularly enjoy our model forecast snow maps, created with BoulderCAST’s “top-secret” snowfall algorithms. Enjoy!

Ben Castellani

Ben grew up in western Pennsylvania and holds both a bachelor's and a master's degree in meteorology. He currently works on a programming language tailored for scientists at Harris Geospatial Solutions in Boulder.

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