Southwest & Central Southern England Regional Discussion

[Buzz]

What is a squall?

http://en.wikipedia.org/wiki/Squall_line

[gottolovethisweather]

What is a squall?

In broad terms.

Noun:

A sudden violent gust of wind or a localized storm, esp. one bringing rain, snow, or sleet.

An even broader description below, taken from wikipedia.

squall is a sudden, sharp increase in wind speed which is usually associated with active weather, such as rain showers, thunderstorms, or heavy snow.^[1] Squalls refer to an increase in the sustained winds over a short time interval, as there may be higher gusts during a squall event.^[2] They usually occur in a region of strong mid-level height falls,^{[clarification needed]} or mid-level tropospheric cooling, which force strong localized upward motions at the leading edge of the region of cooling, which then enhances local downward motions just in its wake

A squall line is an organized line of thunderstorms. It is classified as a multi-cell cluster, meaning a thunderstorm complex comprising many individual updrafts. They are also called multi-cell lines. Squalls are sometimes associated with hurricanes or other cyclones, but they can also occur independently. Most commonly, independent squalls occur along front lines, and may contain heavy precipitation, hail, frequent lightning, dangerous straight line winds, and possibly funnel clouds, tornadoes and waterspouts.^[10] Squall lines require significant low-level warmth and humidity, a nearby frontal zone, and vertical wind shear from an angle behind the frontal boundary.^[11] The strong winds at the surface are usually a reflection of dry air intruding into the line of storms, which when saturated, falls quickly to ground level due to its much higher density before it spreads out downwind.^[12] Significant squall lines with multiple bow echoes are known as derechos.^[13]

[gottolovethisweather]

One point to note is that shouldn't expect snow or even sleet and probably not even Thunder from the anticipated squall line. However, what you can expect are a sudden increase in windspeed, which if caught out in it, can be a very lively affair indeed. Air pressure kicks, substantial Temperature falls, some brief hail and an isolated funnel cloud or tornado are fairly commonplace with such features.

Here is an archived example of a radar signature showing a passing squall.

Here is a separate archived example showing the aftermath of a passing squall, as indicated by my weather station.

Edited November 22, 2012 by gottolovethisweather

[jessandjon]

Thanks ever so much everyone, I still have no rain yet just a lot of wind

[gottolovethisweather]

A Met Office perspective on the next few day's events.

[html][nwvideo]http://www.youtube.com/watch?feature=player_detailpage&v=5H0GayJbUsk[/nwvideo]

[katemart]

seems a tad drier this morning, talking with people from work it seems to have subsided (the flooding) somewhat down north somerset, I guess will change again by the end of the day

Here in Southampton the Council street cleansing teams have been working really hard to clean all the leaves out of the kerbs and gulleys so all the surface water which was lying around yesterday has all gone - bless 'em!

I'm hoping that squall line doesn't fizzle out before it gets here!

Temp: 12C, Pressure: 10.10 mb falling rapidly. Wind S by SW, max gust 59.4 mph at 13.07.

[khodds]

The squall line looks like its intensifying all the time on the radar. Wish it would come through in day light - could appreciate it in its full glory then!

[Nights King]

The squall line looks like its intensifying all the time on the radar. Wish it would come through in day light - could appreciate it in its full glory then!

Yes been watching this squall line all day and it is intensifying quite rapidly now with ppn building in front and behind the main line, looks like rain will start to set in accross the region soon.

Here is the radar from netweather once again for those who don't have it although not sure how often they mind me posting it?

[knocker]

What a depressing day. The cold front has just cleared here. 8/8 st and gusting 40mph although wind has just dropped. Continuous moderate rain that has just eased. Just hope those poor buggers who were flooded in Devon and Somerset yesterday don't get another dose.

[Sainsbo]

Good ol' blustery day here. Max gust only 36mph according to the weather station, but I think there have been 40+mph gusts around here, atleast it felt like it was stronger walking home.

[A.J]

Good ol' blustery day here. Max gust only 36mph according to the weather station, but I think there have been 40+mph gusts around here, atleast it felt like it was stronger walking home.

just down the road from (and up the hill) from you, and it's blowing a hooley here, gusts well over 50 mph, and it sounds like a non-stop roar!....Squall line's probably a couple or so hours away, and will no doubt bring some flooding to low-laying nearby areas, Chippenham, parts of Swindon, Calne etc Edited November 22, 2012 by ajpoolshark

[lfcdude]

just down the road from (and up the hill) from you, and it's blowing a hooley here, gusts well over 50 mph, and it sounds like a non-stop roar!....Squall line's probably a couple or so hours away, and will no doubt bring some flooding to low-laying nearby areas, Chippenham, parts of Swindon, Calne etc

Indeed is very windy. Flooding will be the main issue, For example

Picture my cousin took earlier and put on fb, looks like from the bridge over in Bradford on Avon warters very high

[Nights King]

Wind is picking up quite abit now here! That squall line is quite intense now! Large conifers at work don't look that safe either...

[dancing daisy]

Wind freaks me out. Currently in bed under the duvet listening to it throw things around my garden :-(

What time roughly will it leave Somerset?

[Freddie123]

Wind freaks me out. Currently in bed under the duvet listening to it throw things around my garden :-(

What time roughly will it leave Somerset?

After the main rain has gone through.

[Freddie123]

The wind is very gusty here, I can see the lampposts swaying. Rain has not yet arrived.

[gottolovethisweather]

The squall is currently just clearing parts of Plymouth, Exeter and Newport judging by the radar. The next port of call for the squall looks like effecting places such as Bristol, Sidmouth, Gloucester and Worcester in the next half an hour or so.

Edited November 22, 2012 by gottolovethisweather

[jessandjon]

So I take the worst of the rain has left plymouth only had 30 mins or so of what I would call bad rain wind has gone aswell

[SunnySouthCoast]

Hello fellow southern & south wester's

Was nice today, lots of sun, mild (14C) but breezy & is getting windier currently around 35 mph & gusting to 50 mph.

[chris55]

Very very windy here in the last few hours, took the dog up the common and could hardly stand in the gusts, really great stuff feeling the power of mother nature!! Although I did drive past a few fence panels in the road and recycling bins strewn everywhere.

Squal-line just approaching the Westcountry now, looks pretty intense!!

http://www.metoffice...=5&locId=353749

Edited November 22, 2012 by chris55

[Catacol]

A monsoon just hit Wellington - the road and driveway outside my house is a lake, and it is still hammering down. So far 15mins - I would imagine it has been enough already to close all the local roads that were closed yesterday. Flooding is going to be widespread again.

[khodds]

No rain here yet but the lights keep flickering!

[124alex]

Nothing bad to speak of yet, wind very strong though & had a few flashes of lightening. No heavy rain yet just showers.

[AWD]

And so it begins. Torrential rain here, absolutely torrential.

[TimMB]

Heavy rain in Bristol