Storm & Convective Discussion April 2016 Onwards

[Flash bang flash bang etc]

I hate to say this but has all the energy gone for today? I haven't seen any significant sunshine today and I've been all over. The rain has been mental but hardly any electrical activity at all :-/

[Paul1968]

I think that's it for today,hardly any sun either here and heavy rain for the last three hours.Disappointing,yes,unexpected,no.

[Ben Sainsbury]

Possibly I'm being a little optimistic, but I have my eye on this shower, where as it increasing moves towards an area of clearer sky and where most instability is across CS England, it may turn convective. Most likely won't happen just keeping an eye out as think it's appeared too far west, to enter to an areas of instability we shall see.

[Flash bang flash bang etc]

6 minutes ago, Ben Sainsbury said:

Possibly I'm being a little optimistic, but I have my eye on this shower, where as it increasing moves towards an area of clearer sky and where most instability is across CS England, it may turn convective. Most likely won't happen just keeping an eye out as think it's appeared too far west, to enter to an areas of instability we shall see.

I both envy and fear your optimism ;-)

[Ben Sainsbury]

Almost getting too late from the shower that is just passing over me now, moderately heavy rain, although grown in size too. Too late now, too slow moving...

[Mapantz]

I'm under a large shower that has made it here via the wrap-around. Big juicy drops of rain, and very dark. Better than a kick in teeth I guess?!

[Stuart]

SAT 16 APR 2016: A LOW chance of thunderstorms:

A notably cold Arctic airmass will spread south, with scattered showers in the post-frontal environment which may produce some isolated lightning and small hail, falling as sleet or snow over high ground.

http://www.convectiveweather.co.uk/

 

[Greeny]

I think the trouble was with todays potential and it feels weird for me to say but I think the cap was too weak. So given the moisture in the atmosphere when the convection began pretty quickly on the clouds that did form stopped the sun from doing its work at the same time. I'm assuming the convergence did play a role in what we did see.

If there was a stronger cap in place then I think there would have been a longer period of time where the sun was allowed to build more energy before the cap broke and released more energy into the atmosphere.

 

Edit: I thought of this when I passed very low cloud on the way back from Luton. You barely need a trigger for that.

Edited April 15, 2016 by Greenday

[weather09]

A capping inversion being too weak isn't an incorrect thing to say when we're talking about a setup where we have high moisture and instability building in the boundary layer, where there's a substantial 'cap' but we're confident it'll be eroded with significant heating and moistening. That's an ideal scenario (called the 'loaded gun') that we like to see arise during summer, as opposed to a situation with weak capping where updraft strength isn't as strong and rapid. 

But I don't think that's the reason for the lack of deep convection and storm activity today. Quite simply, it looks like there was too much rain/cloud debris from occlusions which will have inhibited prolonged heating of landmass, and therefore build-up of CAPE. Yesterday had it just right (as best as could be given the environment), where we had the prolonged clear spells for the sun to get to work, but with a more moist air mass (increase in dewpoints) on the previous day, and marked converging flow providing ascent. 

Been a decent week though, I think, for storm activity.  Good start the season.

Edited April 15, 2016 by weather09

[Flash bang flash bang etc]

3 hours ago, Ben Sainsbury said:

I can't seem to delete this quote from my browser :-/

Edited April 15, 2016 by Flash bang flash bang etc
Something's gone wrong and I can't reply

[Flash bang flash bang etc]

Well that was weird I couldn't get rid of a quote box from Ben :-/

What at I was intending to say though...

People gotta remember - saying its a good start to the storm season is fine but please don't say it on my behalf - as we have really had nothing from this past week. Very very bad luck I'd say for the central South (in fact most central and western southern parts)

I really thought today would make up for a very poor showing for 2016 thus far, but as regularly happens we lose a vital factor in storm development and the whole thing goes flat.

really thought I'd see something as I've been all over the place this week, but I guess you win some and lose some.

[Chris.R]

 Well nothing within 100 miles of me all week. Not surprised though as we don't usually join in the action till May at least. 

[Neilsouth]

Enjoy!! One of the best night time storms this year so far - Kent 3RD April https://www.youtube.com/watch?v=CfppQlR8YDc

 

Why isn't the video showing??????

Edited April 15, 2016 by Neilsouth

[Spikecollie]

Relax and watch the strike coming out of Aquitaine in France! The storms won't get to me here in Limousin where it's just rainingm but it's nice watching on lightningmaps while reading my book. I need a good quiet night's sleep anyway!

[Greeny]

2 hours ago, weather09 said:

A capping inversion being too weak isn't an incorrect thing to say when we're talking about a setup where we have high moisture and instability building in the boundary layer, where there's a substantial 'cap' but we're confident it'll be eroded with significant heating and moistening. That's an ideal scenario (called the 'loaded gun') that we like to see arise during summer, as opposed to a situation with weak capping where updraft strength isn't as strong and rapid. 

But I don't think that's the reason for the lack of deep convection and storm activity today. Quite simply, it looks like there was too much rain/cloud debris from occlusions which will have inhibited prolonged heating of landmass, and therefore build-up of CAPE. Yesterday had it just right (as best as could be given the environment), where we had the prolonged clear spells for the sun to get to work, but with a more moist air mass (increase in dewpoints) on the previous day, and marked converging flow providing ascent. 

Been a decent week though, I think, for storm activity.  Good start the season.

Something I forgot to say GFS did forecast very meagre CAPE and I did also look at cloud cover and precipitation later on today and it did show clouds remaining throughout the day. I think GFS painted the right picture thinking about it and what you said. From what I have taught myself through various resources, it was only a single theory factor of why it didn't cause deep convection and to complete that theory the lack of CAPE with a weak cap. However your theory sounds like a fair assumption of what held back deep convection. Its nice to know that the theory I had could at least actually arise and be a factor in some scenarios.

Thanks for your thoughts on it weather09 its good to have second opinions.

Edited April 15, 2016 by Greenday

[Arnie Pie]

Short time lapse of updrafts over Birmingham from Wednesdays thunder storm

 

Edited April 16, 2016 by Arnie Pie

[Speedway Slider]

Heavy showers all around Leicester, yet immediately above there's enough blue sky to make a sailors suit!!

Convection is going on, but slow going over Leicester, central Leicester.... Here's a view from the east.

[toggerob]

First signs of convection here in the Peaks, from the Cat and Fiddle webcam.

[Arnie Pie]

32 minutes ago, Speedway Slider said:

yet immediately above there's enough blue sky to make a sailors suit!!

Cracking comment Speedy...

same here....heres the view over your way from Birmingham

Not expecting any activity today.... but it`s lovely out their

 

[Gordon Webb]

seem to be having a hail shower here , sort of weather you'd expect in january or february not half way through spring

Edited April 16, 2016 by Gordon Webb

[toggerob]

Small wet hail turned to light snow here now as the shower-clouds begin to move in.

[knocker]

 

[NUT]

Just had a fairly decent hail shower in my neck of the woods

[weather09]

43 minutes ago, Gordon Webb said:

seem to be having a hail shower here , sort of weather you'd expect in january or february not half way through spring

Actually, hail occurrence is most common during spring and summer, when increased heating of landmass supports the development of strong updrafts and cumulonimbus clouds, allowing for the formation of hail.  Showery weather, in general, is usually what we expect during spring when increased solar input under still cold mid-levels from the cooler seasons generates instability and causes showers. Link below for more on hail formation. 

http://www.metoffice.gov.uk/learning/learn-about-the-weather/weather-phenomena/what-is-precipitation/hail

[Spikecollie]

1 hour ago, Speedway Slider said:

... there's enough blue sky to make a sailors suit!!

That was always a favourite saying of my Dad's, except he used to say "...to make a sailor a pair of trousers"!