IMO the best weather tool you can have is access to the rainfall radar (I use
Netweather's radar) - which tells you where it is raining, how quickly that rain is approaching you, and whether it is a light shower or a day long deluge. Meaning you can make a real time forecast for your specific location rather than relying on what a computer thinks might have happened (which is all most forecasts are - algorithmic interpretations of raw computer model putput). As an amateur weather forecaster, I use model output to get an idea of overal likely conditions this weekend, but radar tells me all I need to know on the day.
Access to MetO 'fax' (synoptic) charts is also useful, if you know how to read them. You can get them on the
MWIS website - as well as a real person's interpretation of the computer model output.
Edit: Netweather now have a free android radar app available :
https://play.google.com/store/apps/details?id=com.netweather.stormradar&hl=en_GB