All forecast models have similar methods of analyzing the input data to produce a forecast.
However, there are so many different observations that can be considered that each model chooses the values that are more important. Observations, however, are not collected in perfectly spaced intervals. Focus on the United States Relocatable - High resolution models which do not cover a specific region. They have a limited range, but the tradeoff is the higher resolution Inputs Models require the use of specific input variable information in order to calculate output. The ETA model makes use of temperature, wind, moisture, ocean surface data, and precipitable water data as provided by rawinsondes, aircraft, wind profilers, and GOES satellite.