After a cold March, April jump-started Spring 2013. The key moment when spring started was thundery showers on 12 and 13 April: a cold front wrapped round a depression broke the Arctic block. This allowed much warmer upper air temperatures to stream in from the south and west pulled in as the jetstream meandered north of the UK. Temperatures leapt from around 10ºC to 18ºC daytime max over the 12 and 13 April. April was a dry month with only 38.6mm of rain compared to 68mm in March and 114mm in December 2012. Nearly half of the monthly total rainfall fell on the 12&13 April during thundery weather along a cold front which swept away the cold and brought in warmer and more humid tropical airmasses. April rainfall after that wet spell amounted to less than 6mm with sunny and dry weather dominating through to the start of May.
Here is a movie of clouds seen over Reigate in April! 😉