GFS V16: What’s new under the hood?

The GFS gets an upgrade to version 16 this month. What should you expect? Image credit: NOAA/NWS

Starting in early March, the United States-based GFS model will get its first major update in 2 years. Currently, it’s running version 15. The upgrade to version 16 will provide a number of changes, and some improvements.
Let’s take a look at what you can expect:

Cloud physics. One of the biggest improvements touted is that of cloud cover. And, on top of that, precipitation. Early model evaluation shows that it does have a bias toward snow that is heavier than it should be. But, the GFS frequently blew the track and the amounts 5 days out, worse than the European model. That gap seems to narrow with version 16. It also should handle thunderstorms better as well.

Resolution. it increases vertical resolution from 64 to 127 layers. And, it raises the top layer from 54 to 80 KM high. This will provide the model with a better starting basis with improved resolution of the data. Meanwhile, horizontal resolution goes from 13 KM to 10 KM. This is also a significant improvement.

Temperature: the winter cold bias of GFS15 has been eliminated in the Northern Hemisphere. However, there is now a bit of a summer cool bias in the northern hemisphere, but nowhere near as bad its current winter cold bias.

Ensembles: Ensembles show a wider spread. This could be bad, or good. If it captures more extreme events, this could be a good thing. If it is just more noise, however, that would be a bad thing. Unfortunately, modelers think that some of this is more noise than signal, so we will have to wait to see how this plays out.

These are some of the major changes going into this version. However, others who have been looking at the model since it has been testing in public have noticed no major overall improvements, except to clouds and the winter cold bias. Further improvements are on the way for version 17, which is likely still a few years away.

In any case, this will be rolling out on AllisonHouse this month (February, 2021). Check it out and see what you think!

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