Theres no way stevenage will miss out. Even if you get a couple hours of heavy snow before turning to rain/sleet. Expect the 12z to fall back in line again. In my opinion, aslong as you live north of the M4, you will see snow, whether its for 2hrs or the whole day. Actually i even think central southern england will see a period of snow early hours Thurs, but will turn to rain mid morning. Anyway as i say, its only my opinion.