Most of the sites you will use for forecasts ie Accuweather and Metcheck etc only use one dataset from one of the models be it GFS,ECM or MET etc and so they are fairly unreliable if that particular model is performing poorly. This is why at times one site can seem better than another yet on a different day it will seem poorer and so on. By far and away the BEST site to use is this one
http://expert.weatheronline.co.uk/daten/proficharts/en/nae/2010/07/08/basis18/ukuk/tmp2/10070900_0818.gif
This is a high dataset run of the MET and is THE most reliable real time data available to the general public. You can change the map by clicking on the datasets to the left but you may have to do a little research to see what they actually mean as I aint gonna cover them all as it would take to long [

][B)]The precip and temp ones are probably all that you will need and the 2m temp is the temp at 2 metres above ground level. If you use the pressure charts then you can see by the distance between the isobars what the wind will be like and the general direction and whether there are any predicted wind changes which may put you in the right peg at the right time [

][

][:T]This model is run 4 times a day and to change the times then you need to click on the hour changes at the top (0-48) Hope this helps someone [:T][

][8D]