This app uses the brilliant rNOMADS package to pull gridded NOAA model data and plots a heat map of the forecasted temperature change between 2 models for a certain forecast time.
This information can be especially useful in identifying if models are trending colder or warmer, for instance.
This app, being in it's infancy, uses the 2m temperature forecast from the North American Model (NAM) which goes out 84 hours. However, there are over 60 models you can grab forecasts for and hundreds of atmospheric variables within each of those models to choose from.
The reference model run will default to the most recently available model run, while the comparison model run will default to the second most recent run. You are free to select any model run in the previous 7 days. Time stamps will be displayed in UTC/Zulu format, which is the norm in the meteorological community. As a reminder, EST is 5 hours behind (CST 6, MST 7, PST 8, etc). So a forecast time of 12Z would convert to the forecast being valid for 7am EST.