As they currently stand the Carterlake/AJAX templates are (as you say) really set for using Weather-Display for routine uploads (many of the pages have embedded %wdtags% which are substituted by WD for weather variables upon upload).
The clientraw.txt produced by WD is the key file for the AJAX updates as windy said.
The AJAX script now comes in two flavors, one for Weather-Display (using clientraw.txt) ajaxWDwx.js and one for VWS using the VWS WeatherFlash wflash.txt/wflash2.txt files (ajaxVWSwxf.js). With a bit of coding, either script could be adapted to fetch a flat-file (either space, comma or tab-delimited) routinely from your website and modify <span class="ajax" id="ajax...."></span> tags on your webpage. AFAIK, there's no built-in flat-file in wview that's uploaded with the rapidity of clientraw.txt (WD) or WeatherFlash (VWS) .. both offer 5-second or less updates, so you'd need to set up a flat-file layout with the weather variables you want to "ajax", and adjust the code of one or the other AJAX script to use the matching offsets for the variables you want.
I wish you great success with your coding project!
Best regards,
Ken