GFS, HRRR, ECMWF and the NWS forecast: which wind model is right?

Every wind forecast starts with a numerical weather model: a simulation of the atmosphere run on a supercomputer. Different models make different trade-offs between detail, range and update speed.

The main models

• HRRR (High-Resolution Rapid Refresh), run by NOAA. A 3 km grid over the US, updated every hour, looking about 18 hours ahead (48 hours on some runs). Excellent for today’s thunderstorms, lake breezes and timing of fronts.
• GFS (Global Forecast System), NOAA’s global model. A coarser grid but a 16-day range. Good for the big picture several days out, weaker on local detail.
• ECMWF IFS, the European Centre’s global model. Widely considered the most skillful global model in the 3 to 10 day range.
• ICON (German Weather Service) and GEM (Environment Canada). Independent global models often used as a second opinion.

What the National Weather Service publishes

NWS forecasters do not hand you a single model. They start from the National Blend of Models, which combines dozens of model runs and corrects them for known biases, then adjust the result using local knowledge. The final forecast is published as a 2.5 km grid covering the whole country.

Lakeglance uses that NWS grid for every lake. It reflects a forecaster’s judgment, it is updated several times a day, and it is the same forecast behind official advisories.

When models disagree

If the forecast changes a lot from one day to the next, the models are disagreeing. Treat anything beyond three days as a trend, not a plan, and check again the evening before you go. The closer you get, the more the high-resolution models take over and the better the forecast gets.