The meaning of acronyms:
UTC - Universal time coordinated
TCC - total cloud cover in %
TP3h - total precipitation (snow + rain) in mm/3h
T2m - temperature at 2 m above ground in °C
V 925 hPa - the wind at the height of 925 hPa pressure level
(around 700 m), plotted using the wind barbs*
R+T+V 850 hPa - relative humidity in %, temperature in °C and
wind (wind barbs) at the height of 850 hPa pressure level (around 1500 m).
Winds are plotted using the standard barbs (5 knots - short hash, 10 kts - long hash, 50 kts - filled flag). The wind speed is the sum of all hashes/flags. The wind barb points in the direction from which the wind iz blowing. Other meteorological parameters are plotted using isolines and colours (wind speed, temperature, humidity). Past 3 hour total precipitation is plotted together with the cloud cover at the time of the forecast.
More information about the model at http://www.cnrm.meteo.fr/aladin.