You will find in the 520 manual ( plus other 500 variants ) you may fly in falling snow providing you have the following. No centre seat pax ( never been able to work this out or find anyone who knows - anyone enlighten me ? ); autorelight on and armed, I would suggest that anti ice is on as the temp will be below 5 degrees and you certainly have visible moisture.
Other points, as you will have cabin heat and anti ice on watch your TOT espically if you are heavy. TOT starts to rise the inlet may becoming blocked - unlikely but possible.
Heed everyone else's advice get someone to show you
What Notar do you fly in UK, presumably a 600 as there are no 520 in UK I think ???