ForeFlight Global Winds, 150M Served

Last night we pushed a large set of updates to the servers that power ForeFlight Mobile. Many of the improvements were for features you will see in the near future, so we’ll save that list for forthcoming release notes. One of the enhancements included, and available to ForeFlight Mobile customers today, is the new ForeFlight Global Winds engine.

This new capability allows us to provide winds aloft forecasts for any point on the planet up to 54,000′ (FL540). ForeFlight Mobile will now compute the wind impact for any route of flight: flight plans using airways, SIDS, STARs, known airports, any waypoint pairs, and even a string of custom user waypoints or lat/lon entries.

Previously, computing the wind impact required interpolation using National Weather Service wind reporting stations and identifying stations that were close to route waypoints. Depending on the route planned, a nearby station was not always available. In that case, we didn’t show winds aloft impact because interpolation using far away wind reporting stations could cause gross errors. The ForeFlight Global Winds engine now elegantly blends observed data from the National Weather Services and computer model data for the entire planet.

Nothing changes faster than the wind, so your mileage may vary as always when it comes to using forecast data to compute the impact of winds aloft on a flight plan. That said, ForeFlight Mobile is now smarter than ever about the impact winds may have on your flight. Enjoy!

The Science

The engine produces forecast grids of winds, temperatures, turbulence, and icing covering the entire world, making them applicable for planning any length of flight anywhere on the planet.  Forecasts are updated four times each day by processing output from the National Weather Service’s Global Forecast System (GFS) numerical weather prediction model through a suite of custom algorithms to improve usability for aviation planning operations.

The GFS model itself is a state-of-the-science computational fluid dynamics (CFD) code that incorporates a plethora of global weather observations collected by a variety of surface, aircraft, and satellite-based platforms.  Via advanced data assimilation techniques, these observations are used to create a three-dimensional gridded analysis of the state of the atmosphere.  Then, a large supercomputing system advances the basic weather elements forward in time via a complex set of differential equations that describe momentum, heat, and moisture changes as a function of time, producing global grids of forecast data on a grid covering the entire world with 0.5 degree latitude/longitude spacing.

The raw data grids are received from the NWS and complex algorithms are applied to compute additional parameters such as turbulence and icing potential and converts the output from meteorological coordinates to flight levels used by aviators of all types.

150 Million Served

We did some crunching on server stats during the update. Reports show that the ForeFlight Mobile servers are doling out more than 150 million weather “tiles” each month. That’s a lot of radar and satellite data – more than 5 million requests a day. Our weather image servers are running at 99.993% uptime with only 3 minutes of downtime, as the graph from our server monitors below indicates.

Uptime for ForeFlight (SPLEX): 08/02/2011 - 09/01/2011