About this product
The Global Forecast System is NOAA's flagship global model, run four times a day out to sixteen days; this page carries the first ten. For California it is the long-range view: the storm door opening or closing, an atmospheric river taking shape over the Pacific days before landfall, a ridge building over the Great Basin. The Eastern Pacific and Pacific Basin views above exist for exactly that — most of what arrives here is visible out there first, and precipitable water with the wind overlay on is the picture to watch it in.
These charts are drawn from the GFS surface-flux files on the model's own 3072×1536 Gaussian grid at 0.117° — about 13 km — rather than the coarser 0.25° product files most sites draw. A 13 km rain core really is more intense than the 25 km field that smooths it. Colour ramps are pinned to absolute values, so a loop shows intensity changing, not a palette re-fitting itself.
For hour-by-hour California detail, the 3 km HRRR is the sharper tool inside two days, and the National Blend is the calibrated forecast. The GFS is one model's opinion, ten days out; treat it as a synoptic instrument. Watches, warnings and advisories come from the National Weather Service — see the California alerts desk.
Data from NOAA/NCEP, rendered by the Forecast Network's shared pipeline and read here from the same feed forecasteagle.com serves. U.S. government work, in the public domain. Golden State Weather is not affiliated with NOAA or the National Weather Service.