what is a thunderstorm?....

[mushymanrob]

it seems that evertime it thunders everyone says 'did you see that terrific storm'?..

but most of thundr isnt associated with an actual 'storm' is it?

what is the difference between 'rain accompanied by thunder', (thundery rain)... 'thundery showers', and 'thunderstorms'? ... i think its pretty self explanitory but i was wondering if there is a definitive meterological discription...

[The PIT]

it seems that evertime it thunders everyone says 'did you see that terrific storm'?..

but most of thundr isnt associated with an actual 'storm' is it?

what is the difference between 'rain accompanied by thunder', (thundery rain)... 'thundery showers', and 'thunderstorms'? ... i think its pretty self explanitory but i was wondering if there is a definitive meterological discription...

Well the other day we had one flash of lightning in a heavy shower and that was it. I called it a thundery shower. Thundery rain is just heavy rain without the lightning. I suppose the Met office somewhere have a min number of strikes to call a storm a storm or not.

[Guest Nimbus20]

One easy way to find out definitions like this is to go to Google and in the search box type "thunderstorm=" (without the quotes) and then links will appear providing (hopefully) the meaning you are looking for. The same thing can be tried with all meteorological words and phrases.

Edited June 16, 2007 by Nimbus20

[Snowyowl9]

I say a heavy/shower with a rumble or 2.

If more with some lightning and thunder or no lightning and just thunder a thundery shower same goes for thundery rain.

Moderate amount lightning and thunder a thunderstorm.

Or in yesterday`s case with quite alot of CG`s/CC`s and sheet with torrential rain/hail a major thunderstorm.

Then there`s a severe thunderstorm with frequent CG`s near continuous thunder.

When it comes to nightime though you can get lightning without thunder from either distant cells or above your house.

Edited June 16, 2007 by Snowyowl9

[SnowJoke]

I think it's a miss conception that you get lightning without any thunder. During the summer months as a child when we'd be down the east coast on holiday we'd frequently see lightning in the distance or over the north sea. My mother would say along with my nan that it was just summer lightning, therefore no thunder. Looking into storms and lightning over the last few years i've come to learn things about thunderstorms ect..

Lightning being light can travel over much greater distances and tends not to degrade with distance like sound waves and thunder do. Hence during nightime hours you can sometimes see lightning nearly 50 miles away. It also appears to be brighter in nature if there is a decent ammount of mid to high level cloud cover, as this reflects and enhances the lightning. A little bit like a flourescent light tube. Also sometimes you can see lightning without hearing the thunder because the actual discharge is high in the atmosphere or other atmospheric conditions limit the distance the sounds waves can travel and spread out. I'm pretty sure there always is a thunder / sound wave discharge with lightning just sometimes you cannot hear it.

Snowjoke.

[Paul Sherman]

This is one subject that has me tearing my hair out. Almost all of the Storms this week (Bar Friday) have been Thundery Showers and not Full blown Storms. The area that hit the Midlands yesterday was an MCS, Not a Severe Storm, there were a few Severe Storms on the eastern edge, one part of Leicester was receiving 300mm per hour at one stage, (That is a Severe Storm) It is all too easy to see torrential rain with about 5 Cg's and rave about it being the best storm for years, but in reality it is just a very weak Thundery Shower. We very rarely get Severe Storms in this country, maybe on no more than 5-10 days per year, a lot of our Storms are Single Cell or Pulse Storms, with Multi Cells arriving between June and September (Usually) We can average 1 or 2 Supercells per year, but without Doplar can we really put the nail in the coffin on this subject as well. All I will say is if you have sampled Supercells, you will certainly know when one hits you, these generally but not always occur with Capes of over 1500jg and with cloud tops way above 35,000 feet, we do get Low Topped Supercells in this country but again with lack of proper radar these are hard to distinguish.

Nick F has a very good written article in the Pinned thread at the top of this section telling you all about the different types of storms we can get in the Uk and what conditions usually make these happen.

Paul Sherman

[pottyprof]

I had a weak storm with all the right concoction around me on the 15th for a huge storm, but things didn't all come together. 4/5 flashes.. That isn't a storm...

Today (16th) I saw a rotating storm. But it was a developing storm. Again 7/8 flashes.. Not a true storm but a developing storm with an interest.

I think there are people out there with a lot to learn.

[SnowJoke]

I think there is alot of confusion in the UK to actually determine what is a thunderstorm or not, usually it's very hard to distinguish between a true thunderstorm and a thundery shower / thundery rain as most convection that takes place tends to be very congested and messy making it impossible almost to view any cloud structures. If i'm not mistaken a true thunderstorm has to have a correct level of ingredients. ( Inflow, mesocyclone or strong updraft, precipitation core, anvil reaching around the 30,000 ft mark and an outflow boundry! ) please correct me if i'm wrong here but the only storms with these characteristics tend to be imported from france during the summer months or very rarely form due to exceptional conditions and above average temperatures.

Snowjoke.

On another note, the MET radar appears to be working once more!

Edited June 16, 2007 by SnowJoke

[Paul Sherman]

Not strictly true of Uk Thunderstorms SJ, They dont have to have a Mesocyclone (Supercells usually Do) and Outflow Boundaries are areas where storms are likely to fire up from previous days storms, they can be seen on satelitte pictures usually the day after an MCS Has gone through the area if enough Instability is around for new storms. Dont know about the anvil question,

The most common types of Storms in the Uk are Multi Cell Clusters, the convergence zone systems are great for lots of areas seeing Thunderstorms, as these are generally connected with MCS Type storms like we had on Friday, these areas of Storms can be 100's of miles across and feed off each other, they usually pulse up and dissipate continually in a cycle and each cell can last for between 1 to 2 hours, new cells continue to build within the system until the system gusts out. The cool outflow finally undercuts and chokes the warm inflow, then it goes to crap. The single cell storm needs a powerful updraught but only usually has a cycle of around 30 minutes and are not more than 1-2 miles across, the wind velocity, relative to the storm motion does not change that much with height and hence inflow is not such an issue, these storms can hang around in areas "Slow Movers" usually in slack conditions.

Hope this helps

Paul S

[pottyprof]

I have a photo of inflow from earlier.. I'll do that tomorrow though.. camera batteries are on charge... spares have been borrowed by the brats..

[Snowyowl9]

This is one subject that has me tearing my hair out. Almost all of the Storms this week (Bar Friday) have been Thundery Showers and not Full blown Storms. The area that hit the Midlands yesterday was an MCS, Not a Severe Storm, there were a few Severe Storms on the eastern edge, one part of Leicester was receiving 300mm per hour at one stage, (That is a Severe Storm) It is all too easy to see torrential rain with about 5 Cg's and rave about it being the best storm for years, but in reality it is just a very weak Thundery Shower.

Paul Sherman

Very interesting

There must of been 40 Cg`s on Fridays storm that`s without the other lightning as there was 3/4 on the go here as there was the convergence zone coming from the SE with other cells building around.

As yesterday they were just thundery showers and I always thought that you can`t get a tornado unless there`s a thunderstorm either but a funnel cloud yes as I`ve seen one in just a normal looking shower cloud which lasted for 30 mins a few years ago.

[kentish_sally]

Paul S, You mention UK not having doplar - Do you think thats something that will ever be introduced in the UK or due to the small size of the country it would be deemed not nessecery?

[PersianPaladin]

This is one subject that has me tearing my hair out. Almost all of the Storms this week (Bar Friday) have been Thundery Showers and not Full blown Storms. The area that hit the Midlands yesterday was an MCS, Not a Severe Storm, there were a few Severe Storms on the eastern edge, one part of Leicester was receiving 300mm per hour at one stage, (That is a Severe Storm) It is all too easy to see torrential rain with about 5 Cg's and rave about it being the best storm for years, but in reality it is just a very weak Thundery Shower. We very rarely get Severe Storms in this country, maybe on no more than 5-10 days per year, a lot of our Storms are Single Cell or Pulse Storms, with Multi Cells arriving between June and September (Usually) We can average 1 or 2 Supercells per year, but without Doplar can we really put the nail in the coffin on this subject as well. All I will say is if you have sampled Supercells, you will certainly know when one hits you, these generally but not always occur with Capes of over 1500jg and with cloud tops way above 35,000 feet, we do get Low Topped Supercells in this country but again with lack of proper radar these are hard to distinguish.

Nick F has a very good written article in the Pinned thread at the top of this section telling you all about the different types of storms we can get in the Uk and what conditions usually make these happen.

Paul Sherman

300 mm/hr? How do you know? That is off the scale and as far as I'm aware there is no radar or accurate account of such a high intensity in the midlands recently.

Please enlighten me.

[SnowJoke]

Paul S, You mention UK not having doplar - Do you think thats something that will ever be introduced in the UK or due to the small size of the country it would be deemed not nessecery?

I don't think it has any relation to the size of the UK, it's more like cost i'm affraid. No one in the UK ever wants to spend money unless something major happens and then it's always to late, the damage has been done!

[pottyprof]

300 mm/hr? How do you know? That is off the scale and as far as I'm aware there is no radar or accurate account of such a high intensity in the midlands recently.

Please enlighten me.

Sam Jowett's weather station recorded a rain rate of 408mm/hour at 1500 on the 15th PP. It's not all down to radar...

[ANYWEATHER]

Well ,i always thought a thunderstorm was thunder heard and lightning. I would say thats a thunderstorm even if you dont get any rain! But...and i mean "but" evryone as there idea of a thunderstorm and this could mean to some folks ..flash flooding without any thunder and lightning. It seems to me every one as there idea of a thunderstorm, just like everyone has there idea of a Summers or Winters day. But as i said i think the above.

[PersianPaladin]

Sam Jowett's weather station recorded a rain rate of 408mm/hour at 1500 on the 15th PP. It's not all down to radar...

Ahh...somebody managed to record the actual event. Fair enough.

That really is incredible rainfall intensity. Must've been very localised tho.

[Supercell 89]

Well here's my views on the subject:

Thundery Rain: To me thundery rain is just rain and thunder plain and simple, or as a rainstorm.

Thundery Shower: Basically a thunderstorm that lasts anything from 10 - 30 mins (e.g. pulse storms )

Thunderstorm: Proper thunderstorms to me, last for over 30 mins typically 45 - 60 mins, violent severe storms lasting longer. ( e.g. MCS, Supercell )

Static/Electrical Storm: Just thunder & lightning none or very little rainfall, ( not to be confused with a storm in the distance lol ) saw one in spain once very intertaining.

If it rains when and a flash of lightning goes off but only 1 - 2 flashes occur afterwards to me thats not a storm, above 10 flashes to me is countd as one, i could waffle on about intesity but i wont, for now lol

[mushymanrob]

when i was younger (late 60's early 70's) it seemed that every year we had a superb storm. these followed a similar pattern. the breeze was southeasterly, the sky darkend in the southwest, we could hear thunder in the distance, the storm was moving northwards, it always seemed to hit my west first, as if the storm line was on at an angle as it moved north, soon we could see the base of the cloud with a dramatic updraft in front of it, when the grey base was over us that when torrential rain and frequent thunder and lightening occured. this lasted around an hour to an hour and a half, afterwards the storm cleared and the sun came out! no lingering grey murk... and the east was the last place to get it as it moved north.

there was one of these on either 31st july or 1st august 1972, and one on a saturday in mid september 1973.

only very rarely have i seen storms like this since the mid 70's... pity... they were my fav forms and seemed like an annual event back then.

[Harry]

My perception of the 'thundery terms' are:

Thundery Rain : An organised band/merged showers to form longer outbreaks of rain with accompanied, quite intermittent thunder and lightning.

Thundery Shower: Simply, a shower generally producing thunder and lightning.

Thunderstorm: Larger in size with more longevity than a shower. Produce quite regular thunder and lightning.

Severe Thunderstorm: Looking terms of hours rather than quarters of an hour. Torrential rain, 6-7 flashes per minute, large hail, would be looking for funnels!

In the last 5 years, Ive seen a few severe storms roll past and hit by one. I seem to remember being younger we used to import HUGE storms from France which would last hours, with very frequent lighting, incredible booms of thunder and the most immense rain you'll ever see! They dont seem to occur as regularly now :-( lets hope tomorrow night offers some of the old times :-)

[Hodgheg]

My thoughts are:

Thundery shower: Small thunderstorms that dont last long. Sometimes occur in winter low pressures.

Thundery rain: Storms embeded in a rain band. Not usually very strong.

Thunderstorm: Occurs on hot and humid days in summer can be severe.

[SP1986]

Very Interesting to see peoples different perceptions, I'm sure there are definitions but these are my addings from experience and learning:

Thundery shower:

Tends to follow fronts, and tend to occur within shower clouds - the cell is sufficiently strong enough to cause occassional thunder and lightning, usually about 100-200j/kg, and more often than not associated with a polar airmass.

Thundery rain

Thunderstorm cells with a certain amount of cap on them, tends to lose quite abit of the energy it may start with, usually associated with warm fronts rather than cold fronts. Again occassional lightning and thunder but more emphasis on IC lightning and high level thunder.

Thunderstorm

A unique cell with enough convective solar energy and the right ingredients to produce a cell that starts and finishes a thunderstorm, such is the raw energy found in this cell, lightning may be frequent and thunder may be constant. Tends to be found as individual large cells generated by heat or generated on/just ahead of a productive cold front

Embedded Thunderstorms

Part of a cold front system, very lively, even though surrounded by nimbostratus, or altocumulus based cloud. The front may produced constant rain, however the embedded cells may produce heavier rain along with thunder and lightning of varying severity.