By: Stephen McCoy
No major changes in the forecast for this weekend's race at Circuit of the Americas, though the models are still showing a wide range of temperatures for the high on Sunday. Confidence is not high for the temperature as a result of the model spread. In addition, timing of the high is uncertain, but looks increasingly like it will occur in the morning due to the cold front moving in and dropping temperatures for the rest of the day.
The SREF plumes ensemble spread shows a mean temperature around 50F on Sunday, though with very low confidence as not a single member matches the mean line.
The 06Z and 12Z GFS model runs (blue lines) show a spike in temperatures on Sunday as the model shows the front passing in the afternoon, allowing temperatures to warm from daytime heating. However, the 06Z and 12Z runs of the NAM (red lines) show the front passing in the morning, with cold air moving in from the north behind the front. Daytime heating still occurs in the NAM runs, but the effect occurs hours after the front has passed.