If your webapps are really two different parts of the same project you can combine them as separate modules in a single IDEA project and start Tomcat
If you really need to use separate IDEA projects you can use 'Tomcat Local' run configuration in the first project and 'Tomcat Remote' run
configuration in the second so when you start the configuration from the second project IDEA will connect to running Tomcat instance instead of
starting a new one. However you won't be able to debug the same java process from two IDEA projects simultaneously.
"Develop with pleasure!"