Ok, I've just downloaded the omweather source code, and taken a quick look. It appears that they were retrieving all their data from The Weather Channel (weather.com). However, it looks as though the weather.com service has been retired. So, in order to work again, omweather would need to derive its data from some other source...

EDIT: Aha, I see that omweather can access other providers; I'm seeing database for a Russian and a Norwegian service in the application manager. Still, not sure how those would work.

EDIT 2: Ok, I'm running OMWeather now, and oddly enough, it is pulling data down from weather.com just fine...