Thunderstorm Questions

[tornadomanuk]

I thought I would start this post as I'm interested in finding out the answers to a couple of questions I have regarding thunderstorms. The early hours of this morning (19/07/2017) was a great night for storms in my area but I wanted to know -

1. There where numerous cells around me all producing good amounts of lightning - frequent too. The cell to my SW, then W was a particularly prolific one, spitting out lighting (mostly IC) every 20 seconds or so. My question is what causes a highly productive cell to suddenly stop producing lightning. Literally it went from flash after flash to then nothing. Then after 10 minutes or so went back to bombarding the area beneath it with a good light show. Is it to do with inflow feeding the storm to be momentarily cut off? or is it to do with shear?
2. My second question again relates the the fact that numerous cells where surrounding my area. When a lightning strikes, say from the cell to the North, it almost (9 times out of 10) triggers the other cells, some a fair distance away to trigger a strike as well. Is there some relation between each cell, or is it the fact the atmosphere is so unstable that one strike can cause others to happen at the same time?

[Another Kent clipper]

It's the tacograph.  EU legislation, the cell has to take a break every ninety minutes.  

As for real answers, I've no idea sadly.  Hopefully someone on here will have them, however my understanding is that lightning is a phenomenon nowhere near fully explained

[samadamsuk]

As a guess (hoping that someone better qualified can answer this!), I'd expect it's to do with the Cell modes, and where the convergence/divergence is happening. A single cell I suppose will go up, then choke off at some point, unless shear is providing updraft downdraft separation. The transition from CC, then a break, to then CG's is something I saw a lot of in Darwin - storms would go up, the bottom would literally dissolve and you were left with CC within the anvil canopy that was still active. Multicell storms obviously have the same thing going on, however cells are being triggered around the outflow of each other, and you're right RE the inflow - in an mcs system aswell inflow is important in defining where the activity is and the cells firing under the cloud shield. On the slightly larger scale, and it's a painful point  as I was sat in Cirencester watching the south coast get battered and me having nothing!, storms would fall apart as soon as they moved north, with activity kicking off behind, so nothing ever got to me. I'm not sure whether this was a number of things: Convergence above the boundary layer in that area, stabilisation of the theta-w air from previous convection over c/southern England, so no cape inflow, divergence over my area caused by a converging flow aloft in the jet stream, or something else..

Lightning triggering from cell to cell is one of the most amazing weather spectacles I like to watch - have to go back to 1995 around here though for a storm system like that (help!). I would imagine (and your guess will be equally as good mine atleast!) that it is an indirect route, but still a route found, for the charges in the originating storm to equalise themselves. 

 

Samos

[Lauren]

How do we tell the difference between an MCS and lots of separate ones?

[Mtj75]

Does anyone know about elevated  thunderstorms? Why at times are there no gust fronts? Why does the surface winds stay out of the east during the thunderstorms if the thunderstorms are coming in from the southwest?

Edited May 7, 2020 by Mtj75
Typo

[Gleb Berloff]

Hi,

I live in Cambridge, and on the 30th April this year a really violent thunderstorm, with lightning, strong wind, hail and really loud thunder, sped over the city. 

I took numerous pictures of the event- does anyone have any idea what type of storm this is, and is the cloud formation depicted on the first image a shelf cloud? 

In addition, is it just me, or do the clouds have a very slight greenish tinge to them?

Thanks!

 

[Zak M]

8 minutes ago, Gleb Berloff said:

Hi,

I live in Cambridge, and on the 30th April this year a really violent thunderstorm, with lightning, strong wind, hail and really loud thunder, sped over the city. 

I took numerous pictures of the event- does anyone have any idea what type of storm this is, and is the cloud formation depicted on the first image a shelf cloud? 

In addition, is it just me, or do the clouds have a very slight greenish tinge to them?

Thanks!

 

Hi, welcome to NW! The first and last pics are clear pictures of a shelf cloud. A slight greenish tinge could indicate large hail falling.

[Gleb Berloff]

4 minutes ago, Zak M said:

Hi, welcome to NW! The first and last pics are clear pictures of a shelf cloud. A slight greenish tinge could indicate large hail falling.

Thanks! 

Nice to hear that. And yes, there was an exceptionally violent bombardment of hail a few minutes after I took this particular image...

 

[Mtj75]

What is the difference between  synoptic winds, inflow winds, calm before the storm, outflow winds(gust front) and thunderstorm winds associated with squall lines and multicell thunderstorms?

[Paul]

Synoptic winds are non-convective winds which flow between high and low pressure (more info here - https://www.netweather.tv/weather-forecasts/news/10252-learn-about-synoptic-weather-charts---from-fronts-to-isobars)

Inflow winds are the winds created by a storm pulling air (usually warm / moist  / humid air) into it. Outflow winds are from the now colder, fresher air coming out of the storm. On a squall line it's a combination of updrafts and downdrafts, plus wind shear which help to create the very gusty winds.

There's some good info in this article about the different types of storm etc

What are the different types of thunderstorm?

WWW.NETWEATHER.TV

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There are many different types of thunderstorm - from single-cell storms right up to supercells. Find out what the differences are and how to identify them in this guide written by Nick Finnis.