I posted this note over in the Feature Request forum a little bit ago, but I've copied here for convenience:
Well... I still would love to see a data importer for WeatherLink files. I tried using LWC2 as part of a conversion process only to have it crash with an instruction exception when I ran it on Mac OS 10.8.2 and identified a WeatherLink file to convert. I've noticed that many folks talk about WeatherLink .WLK files; however, mine are old Mac WeatherLink files in a non human readable form with a .HOM extension. So that may be the source of the LWC2 crash and in the end a .wlk file converter/importer wouldn't help me.
All that being said, I have managed so far to get my WL data back to the first of 2013 into WeatherCat using an excel template I developed. Although it is still a multi-step process, converting a month's worth went relatively quickly once I had the template built. I'm certainly willing to share the process and template with anyone interested; however, keep in mind that I am working with old Davis Weather Monitor II data, which is less extensive than Davis Vantage or other stations, and my data logger was set for 30 archiving - 48 records per day or 1440 per 30 day month spaced at regular 30 minute intervals. That helped and is taken as a given in my template.
I'm sure this is not as elegant as a well done script and it still takes time & thought; however, it beats the heck for me out of no historical data and for sure trying to do something by hand. I'm now debating whether to tackle 2012, and if so, whether to go back to the beginning of my data in 2005. That still would be a major time undertaking.
A couple things I did learn in the process is to be sure the X_WeatherCatData.cat file actually has a .cat final extension. I am using TextWrangler for final cleanup & processing of my template output and it was appending an additional hidden .txt extension, which then kept WeatherCat from processing the file. Second, be sure the final file is saved with Unix Linefeeds. Again, TextWrangler was saving the files with Classic Mac Linefeeds, which caused a corrupt data error in WeatherCat.
Rick