When looking at raw METAR data on the aviation weather center, "@TOP" appears in the text box where you can type identifiers. What does TOP mean?
In this case, @TOP is the output from the top U.S. airports. You can enter two letter state abbreviations (i.e. @NY, @MO) or country abbreviations (i.e. #GB, #DE). (https://www.aviationweather.gov/help/tutorial)
@TOP is a special code on the aviationweather.gov website. It shows data for the top U.S. airports around the country. This isn't the only special code that can be placed in the box. You can also use the two character identifier for the state to see all data for that state. See the fourth row below.