How the forecast has moved
valid two days out
GFS · Run 00Z 1 Oct · +48 h · Valid Sat 00Z 3 Oct
Region Northern Plains
The readings under the map are for the whole map, not only the part shown.
GFS · Run 00Z 1 Oct · +48 h · Valid Sat 00Z 3 Oct
One moment — 00Z 3 Oct, about 48 hours out — as every stored GFS run has drawn it.
Methodology
Step through the runs and the pressure pattern moves, and the precipitation under it moves with it: that motion is the forecast changing its mind, which is what this site exists to show. Same chart grammar as the surface analysis — the same reduction, the same interval, the same frame; only the issuing run varies.
This map is drawn from model output we store ourselves, not from anyone's picture of it, and is based on data and products of NOAA. The per-city read of the same day — which cities the models are fighting about, and what the discussion makes of it — is on the national page.
Sources and licences
- NOAA: GFS, from NOAA's NOMADS server. US government data, not subject to copyright (NOAA/NWS terms of use).
What we change: each field is cropped to the frame these maps share when we download it, and each map then smooths, contours, differences or ranks those numbers as its Methodology says. These are our maps of the providers' numbers, not their products, and none of them has reviewed or endorsed this site.
Coastlines, borders, lakes and place names: Natural Earth, public domain.