This is an interesting discussion, and I believe what it boils down to is what model(s) the apps/agencies use.
MetO use a blend of DECIDER/MOGREPS/UKV and I understand their 'automated' output is edited somewhat manually.
BBC use mostly ECM (under contract with Meteogroup) for graphics forecasts and the app data is fully automated on ECM output.
Weatheronline and some of the other apps use GFS raw for automated.
This is why you get differences.
I don't like the apps - much prefer to do my own forecasting using blended model data which is better I find.
Originally Posted by: nsrobins