Steps to reproduce the issue:
* Open the Atmospheric Editor
* Browse and select a weather file
* Notice that the weather filename path reflects the selected file
* Click the "View Weather Entries" button
* Close the weather entry dialog window
* Notice how the weather filename path is now empty
This is because the weather file viewer can also generate a new weather file, so it would return the name of that new file. However, if the user just views the data, we returned an empty filename which would overwrite the existing filename.
We added a check to see if that returned filename is not empty (which would be the case when you generate data), and if it is not empty we update the filename. Otherwise, we stick with the old filename.