Weather model maps and archive

The GFS, the ECMWF and its AI model, the HRRR and the NAM as maps: pressure and precipitation, temperature, wind, instability, simulated radar and the upper air. The newest run of each, and every past run the public archives hold, back to 2014 for the HRRR.

The archive

Every run comes from the models' own public archives, read when you ask for it, so any run in them can be shown:

A few runs in each archive were never saved, and older runs carry fewer fields: the ECMWF runs of 2023 have no dew point, gusts or CAPE. A map that is not in a run says so.

How the maps are made

Each map is the model's own output, read field by field from its GRIB2 file, then drawn onto the region at about 5 to 10 km per pixel, so the finest detail of the HRRR shows best on the smaller regions. Isobars and height lines are drawn from the same fields: sea-level pressure every 4 mb, 850 mb heights every 30 meters and 500 mb heights every 60 meters, labeled in decameters. H and L mark pressure centers at least 2 mb above or below their surroundings.

Precipitation on the pressure map is what fell since the previous hour shown: 1 hour for the HRRR, 3 for the NAM and the ECMWF, 6 for the AIFS and the GFS, which reports it in 3 and 6 hour buckets. Total precipitation runs from the start of the run. Upper-level winds are in knots, as on aviation and upper-air charts.

A model run is one forecast, not a certainty. Compare runs and models to see how settled a forecast is, and use the National Weather Service forecast and warnings for decisions.

Sources

GFS, HRRR and NAM: NOAA's National Centers for Environmental Prediction, through the NOAA Open Data Dissemination program. ECMWF IFS and AIFS: ECMWF open data, licensed under CC BY 4.0 (Copyright ECMWF). Maps drawn by WeatherOverTime.