I referred to this blurb from a Washington Post article several days ago:
"The current Global Forecast System - or the GFS - the United States' premier weather model, is running poorly, and there’s no one on duty to fix it.
“There was a dropout in the scores for all of the systems” on Dec. 25, Suru Saha, a union steward at the Environmental Modeling Center in College Park, Md., said of the scoring system used to rank how the forecast models are performing. “All of the models recovered, except for the GFS, which is still running at the bottom of the pack.” Not only does that mean the day-to-day weather forecast is worse, she said, it is also a national security risk.
Saha thinks it has to do with the data format. The model brings in data from all over the world, from dozens of different countries that are now standardizing the format to adhere to new regulations. The Environmental Modeling Center was working to adjust for the new formats when the shutdown started. Saha said that even though the Weather Service is getting the data, the GFS doesn’t recognize the format, so it can’t use it. And a model forecast is only as good as its input data."