NOAA’s computer modeling system that spits out the data used by meteorologists to predict US weather is 40 years old. Or was, rather. Last month, NOAA rolled out a new system that promises to massively improve both near term and far term forecasting. The hope is it will bring US forecasting up to the standard set by European weather forecasts.

Not to get too deeply into the weeds, the new version of the Global Forecast System (GFS), the parent model that NOAA relies on, is called the Finite-Volume Cubed-Sphere (FV3). GFS is essentially a package of equations and formulae that analyze global weather patterns, taking into account atmospheric physics, and deliver data to meteorologists they then use to make particular, location-based predictions. The cog in the wheel is the global weather data. Any murkiness or opacity in that data can cause the inaccuracies we see in regional forecasts, even though those forecasts have consistently and impressively improved in recent years.

Photo: Marco Bicca

The new system just takes this process into the future. Basically, software engineers rejiggered the equations to provide even more accurate small-scale data, so the gap between what a meteorologist sees in global patterns and local patterns is smaller, making predictions easier and hopefully more accurate. The new system better simulates the physics of water vapor, and immediately produces more accurate hurricane and major weather system predictions. It’s also thought that this will help meteorologists take into account how thunderstorms affect weather in surrounding areas to even further localize predictions.


There have been some quirks to work out, some of which was delayed by the government shutdown last year, but the new program has been running concurrently with the old for over a year and NOAA officials are pleased with the results enough to flip the switch and take the new system live.

Hopefully, at the personal level, this translates into even more accurate weather reports when planning that backpacking trip next weekend, or even next month. Snowfall this winter should be more accurately predicted too.

Read more about what goes into this revamp here at NOAA’s press release.


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