To get started.
Rather than mess with your finished maps, create a simple test terrain with one field and use it to experiment with the Cloud Editor (CE).
To create a weather file for the test terrain:
1. Open the CE, click File/New Weather.
2. File/Set Map Size: set the size to the size of your test terrain.
3. File/Open Terrain: select the test terrain map.
4. File/Save As: (name of the test terrain) in the test terrain Terrain Editor (TE) folder. It will create a .awa file.
Now create a weather "front" with the edit tools. Be sure to click "submit" after setting the parameters. (I would start with one front for a simple test.)
5. File/Save: to save the current weather to the test terrain folder.
6. Exit the CE.
7. Open the TE, Build and Save the terrain.
8. Exit the TE.
Now you can use Offline Practice to see the new weather.
(Repeat steps 5 - 8 after modifying the weather file so it will appear in Offline Practice.)
Hope this helps.