What are April showers?
Showers happen all year round but mid spring-April-when we have our longer days and strengthening sun is the time of year they are most common.
Good Morning Britain Weather Presenter Laura Tobin has more in her blog.
After a weekend of showers, I’ve been asked why do we call them April showers?
Showers happen all year round but mid spring-April-when we have our longer days and strengthening sun is the time of year they are most common.
Seasons
The reason for this is down to where April sits in our seasons. Typically during the summer warm air will build across the UK, pushing the jet stream along with it’s weather fronts wind and rain to our north. During the Autumn the jet stream typically moves south bringing winds and rain across the UK. In winter the opposite of Summer the jet stream moves south allowing cold Air across the UK and into spring the jet stream moves across the UK again bringing spells of wind and rain. This isn’t always the case, as we know following the wettest winter on record with not a whiff of snow!
Why April showers occur
In April the land starts warming up from the strengthening sun, however the sea takes a lot longer to warm up as it has a lower specific heat capacity-this is basically it’s ability to hold heat, it has been getting colder and colder all Autumn and winter and is at it’s coldest in March!-So we have a warming land, cold seas and add on to this a cold atmosphere above we are left with conditions ripe to grown showers.
During the day the sun heats the ground, warm air rises, as the air rises it cools and condenses and eventually reaches 100% saturation then a cloud will form.
This cloud is the fluffy cloud we often see and is known as a ‘Cumulus’ cloud and means heap or clump in Latin. As the air rises, more air rushes in from the surroundings (cooler seas) to fill the ‘gaps’ it’s this constants supply of air being warmed and condensing that produces lots of clouds that grow bigger and bigger. On top of this cool air aloft from winter means the air is more unstable and enhances the development of shower clouds.
During summer the whole atmosphere warms this creates more energy and this is when we see bigger more intense showers with hail and thunder more common.
Outlook
This week we’ll have a lot of showers for southern areas. Wednesday into Friday we’ll see a band of rain spreading across the country with colder air flowing in behind. Cold enough for frosts by night and even snow to return, but only over the Scottish mountains!
Brollies at the ready and keep those gloves handy too!