I took a look into the "1.18" branch, cuz I was trying to build it by myself to play with it, but I noticed that some parts of the code have references to unexisting classes.
I tried to replace the missing references with existing code (e.g. replace "ClientConfigData.Storm_Tornado_grabPlayer" with the existing "ConfigTornado.Storm_Tornado_grabPlayer". I don't even know if this will work), sadly, nothing of what I did to the code worked, specially when I tried to patch the WeatherManager.read() method, because the WorldNBTData doesn't exists in the entire repository, and I can't figure out how the class is supposed to work.

Classes (I found) that are broken:

• weather2.weathersystem.storm.StormObject: Missing reference to WeatherUtilConfig
  

• weather2.weathersystem.storm.TornadoHelper: Missing references to ClientConfigData
  
  

• weather2.weathersystem.WeatherManager: Missing references to IWorldData and WorldNBTData, also, the "save()" method is trying to override the one from a superclass (Maybe from IWorldData)
  
  
  

• weather2.weathersystem.WeatherManagerServer: Missing references to WeatherUtilConfig
  
  

• weather2.ClientTickHandler: Missing references to ClientConfigData. This only is easy, because I only need to remove its uses safely
  
  

I don't know if the "1.18" branch is supposed to work or is only a work in progress without any type of testing, but a notice about the status of the branch will be appreciated. Note: I am working with the commit from January 27th for the 1.18 branch.

Also, I see people saying a milestone about the 1.18 port/total mod rewrite status would be really great, and yep, it would be great.

As well, good luck with the port

1.18 source code won't be posted until corosus has it completed for 1.18 as is known for his 1.12 and 1.14 branches it seems.