On Sunday, April 2, 2017 at 8:42:53 AM UTC+1, Col wrote:
On 01/04/2017 15:45, Norman Lynagh wrote:
Col wrote:

There were some around earlier but i seem to have missed most of showery
activity that was around in NW England earlier this morning.

But why do we have the term 'April showers' anyway? Convective shower
activity is surely prevalent in all months of the year, is there any evidence
that in April it makes up a larger proportion of total rainfall, compared to
frontal rain?

It's the month when the first of the 'home-grown' heavy showers and
thunderstorms start to develop over the land as a result of solar heating of
the land. Earlier in the year, much of the shower activity develops over the
relatively warm sea. In other words, April is the month when the summer regime
first presents itself.

Yes, April is certainly the time when 'heat' showers first develop.
However to the public a shower is just a shower and they wouldn't know
if it was generated over the land or sea. So why not March, June or
November showers? What I was getting at was is showery activity in April
commoner than in other months?

--
Col

Bolton, Lancashire
160m asl
Snow videos:
http://www.youtube.com/channel/UC3QvmL4UWBmHFMKWiwYm_gg

I think there are a number of things that come together to give that perception. April sees a sharp drop in vigorous Atlantic depressions, as well s the start of summer convection. NW-N winds are fairly common in April, giving the right conditions. Also summer thunderstorms, whilst clearly convective, are viewed rather differently to April showers.

It's certainly more accurate than equinoctial gales, when gales are less common in September than October, November, December, Jan . . The term probably springs from the fact that the waking up of Atlantic depressions because evident in September.

Graham
Penzance