There's probably a better way, but I do it with a simple html page that is never even displayed or seen. It's only purpose is to give WC something to attach the movie or a single image to upload on a set schedule. Once it is uploaded you (or you template) can do whatever you/it wants with the image(s).
Here's my "page":
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<meta name="generator" content="BBEdit 10.1.1" />
<title>Upload WeatherCatDailyMovie.mov and the 640px backyard image</title>
</head>
<body>
MOVIE$
WCAM640$
</body>
</html>
You don't really even need the stuff between the "<head>" and "</head>".
Now, I simply add this html document to the list in the WC Prefs->On-Line->Custom Web->Additional Files. Clicking the "Add" button brings up a small dialog with a "Set Path" button. Click that and you'll get Navigation dialog where you can select the html file on your hard drive. I check the "Enabled" and "FTP" boxes, set the time interval to 20 minutes.
From now on, WC will look at that file and replace the "MOVIE$" tag with the latest hourly video. The "WCAM640$" tag gets replaced with a 640x480 jpeg. Of course, all the above does is upload the video/imahe to your web space. Getting it on your site should be easily handled by your template or your own html files.
I don't use a complete template nor am I familiar with meteotemplate, but that template's dev visits quite often and he or someone that uses it may be along shortly with a better, more applicable answer.