Convective Outlook

[NL]

Might start getting very interesting in the next couple of hours.

NW 5min rainfall radar.

[dogs32]

yes thats the area thats going to get very squally with or up to 70mph winds I believe..

For my area expected around midnight=ish

On another note a quote from local paper tonight..

Don't worry, folks, it's only a "possibility". It's also a possibility that a giant meteorite will fall on Gloucester tonight - but not very probable.

well talk about Histeria

Only 4=5 hrs to wait if anything developes..

no mention from Penny Tranter on Twister's

here's another crazy quote from someone responding to the Twister threat..

Can you be more specific as to where in Gloucestershire it could strike, Should I baton down the hatches here in Dymock?

Edited November 24, 2009 by dogs32

[Ian Fergusson]

Seeing as Ian is around and hopefully he reads this, I would just like to ask a question as it looks like Ian is a qualified Met etc

Why do the Weathermen/Presenters on BBC Keep on mentioning the chance of Mini Tornadoes when the term simply does not exist, a Tornado is a Tornado period and there is nothing "Mini" about it, or another question is are you told to mention the word "Mini" in the broadcast to keep the public from panicking ?

Just curious as to your viewpoint on this subject as it grates most people interested in the weather and not just on this weather forum.

Paul S

Hi Paul, and apologies for the delayed reply. I'm up again at 0300hrs for work and hence my 'day' (effectively a misnomer) tends to become somewhat obscured by strange dinner times, bedtimes and such-like!

Firstly - I'm by original qualification a (chartered) biologist, not a meteorologist. My initial route to the BBC, many moons ago, was ironically through academia / field research studying sharks and their distribution/behavioural ecology, not the likes of severe convective events (albeit I undertook the latter informally, ever since constructing an ill-conceived - but effective - bamboo and galvanised steel 70ft 'lightning tower' in my parent's driveway in Jo'Burg, 1975, and yes, it worked..... rather well. Far too well, for my Dad's liking)!

I won't bore you with the circuitous route I've taken to now broadcasting in my other lifelong passion (i.e., weather, as opposed to sharks, with aviation coming a close 3rd) but suffice to say that I've had MetO training and do maintain a semblance of the BBC/MetO tradition in employing scientists of one guise or another. After all, my former BBC (now GMTV) colleague Kirsty McCabe was a research geophysicist by original trade (including for NASA), but for sure, she sure knows her Met stuff, big time, after re-training at UKMO!

Now, re your query: This clearly nonsensical term "mini tornado" is not one I've ever seen cited as either (a) scientifically valid nor ( an agreed piece of BBC or any other broadcast weather terminology.

If someone spoke of a 'weak tornado' then fair enough: that's cited against a globally agreed scale of definition (i.e., Fujita's, versus the potentially confusing TORRO bespoke version).

But ultimately, a tornado is a tornado: the use of 'mini tornado' makes little sense to me; much like talking of a 'mini Cumulonimbus calvus' is irrelevant if endeavouring to separate a UK summer cell reaching 26000ft from a towering, growing giant reaching 50,000ft in the tropics.

I'm not sure where you've heard the term broadcast, but I'd doubt it's from an actual meteorologist?

Best

Ian

I'm really pleased to see Ian posting on here as it gives us an extra dimension to our discussions. I was also delighted that Richard Angwin mention on his lunchtime forecast that tonight's front is an ANA cold front. This level of information is great for those interested in the subject and to be honest will fly well above the head of the majority and go un-noticed. My interest in the weather was kindled by Francis Wilson in the 80's who was at the BBC at the time and always gave 'a little bit extra' in his forecasts for those who wanted to listen. Three cheers the for the BBC !

Even Horizon seems to be back to it's old self again recently !

My ultimate achievement was slipping "line convection", "frontolysis" and "tornadic" into three BBC TV forecasts a fortnight ago (with proper explanation, I hasten to add). Rich needs to beat this, so ANA-front is a good start. But he didn't reckon on me being back in work tomorrow at 0400hrs. Can I outdo him? It's possible..... ;-)

Francis also talked of tornadic storms (sic) yesterday in the Midlands on his Sky gig.

[SteveB]

Very windy here already (more so than usual of late). I can't do having another sleepless night, Sunday was bad enough.

All this wind is getting a bit tiresome. Richard Angwin saying a rough old night to come, with showers packing in tomorrow morning & continuing for most of the week.

[Ian Fergusson]

yes thats the area thats going to get very squally with or up to 70mph winds I believe..

For my area expected around midnight=ish

On another note a quote from local paper tonight..

Don't worry, folks, it's only a "possibility". It's also a possibility that a giant meteorite will fall on Gloucester tonight - but not very probable.

well talk about Histeria

Only 4=5 hrs to wait if anything developes..

no mention from Penny Tranter on Twister's

here's another crazy quote from someone responding to the Twister threat..

Can you be more specific as to where in Gloucestershire it could strike, Should I baton down the hatches here in Dymock?

Erm......what's this Gloucestershire tornado threat thing about??? Sorry, maybe I've missed something in the thread (apols if so). There's no specific tornado warning for Glos (or anywhere else). We (BBC/MO) have merely highlighted the broader likelihood, certainly not any county-specific warning..... (and PS, Penny T is fab and absolutely knows her stuff, as I and many others who know her / have been trained by her at Met Office college can attest)

[tornadomanuk]

Absolutely brilliant to see Ian Fergusson posting on here, a very welcome member of the team! (although how on earth do you put up with Steve Yabsley???!!). Richard Angwin also came up with the point of tornadoes being called 'mini-tornadoes' is ridiculous in his lunchtime forecast on BBC Somerset.

Back to the current situation, the winds have definitely increased alot down here in the last hour or so, looking forward to radar watching!

[dogs32]

Erm......what's this Gloucestershire tornado threat thing about??? Sorry, maybe I've missed something in the thread (apols if so). There's no specific tornado warning for Glos (or anywhere else). We (BBC/MO) have merely highlighted the broader likelihood, certainly not any county-specific warning..... (and PS, Penny T is fab and absolutely knows her stuff, as I and many others who know her / have been trained by her at Met Office college can attest)

Hi IAN

Quoting from

GLOUCESTERSHIRE is braced for a potential tornado tonight.

County weather expert Ian Thomas said there is a real possibility that high winds tonight could create a tornado at around midnight into the early hours of the morning.

Ian said a deep low swinging off the Atlantic has a wrap around cold front associated with it.

"It's going to get very windy with gusts of between 50-60 miles per hour. There will also be rain as a cold front sweeps across the county which is when the activity will start - squally winds with up to 70mph gusts and the possibility of a tornado."

Ian said it may strike anywhere in Gloucestershire but stressed it was only a possibility and he urged people not to panic.

http://www.thisisgloucestershire.co.uk/gloucestershireheadlines/Gloucestershire-tornado-warning/article-1538606-detail/article.html

laughing at the crazy response's from the public like

My calculations have another strike at 00:46 at the head of the estuary, most likely in the Hempsted area as the effects are exacerbated by the peak of high tide bringing cold water to bear. Watch out !

and this classic post

Can you be more specific as to where in Gloucestershire it could strike, Should I baton down the hatches here in Dymock?

and Penny Tranter is a excellent forecaster...was just mentioning on her earlier forecast there was no mention of twister's..

Yes couldnt agree more that this NOT just a Glos County warning..

Edited November 24, 2009 by dogs32

[sammie]

Hey guys I hope you didn't mind me jumping in and posting along this one - even though I understand a tiny amount of what you are acually saying haha! I'm struggling to even understand the set up to this one but I'm sure that tonight will be interesting to watch on the radar. Squall line is starting to light up on the radar =D

[Ian Fergusson]

Hi IAN

Quoting from

GLOUCESTERSHIRE is braced for a potential tornado tonight.

County weather expert Ian Thomas said there is a real possibility that high winds tonight could create a tornado at around midnight into the early hours of the morning.

Ian said a deep low swinging off the Atlantic has a wrap around cold front associated with it.

"It's going to get very windy with gusts of between 50-60 miles per hour. There will also be rain as a cold front sweeps across the county which is when the activity will start - squally winds with up to 70mph gusts and the possibility of a tornado."

Ian said it may strike anywhere in Gloucestershire but stressed it was only a possibility and he urged people not to panic.

http://www.thisisglo...il/article.html

laughing at the crazy response's from the public like

My calculations have another strike at 00:46 at the head of the estuary, most likely in the Hempsted area as the effects are exacerbated by the peak of high tide bringing cold water to bear. Watch out !

and this classic post

Can you be more specific as to where in Gloucestershire it could strike, Should I baton down the hatches here in Dymock?

Ok..... thanks. Had not seen this. And everything you've cited here, including public responses and associated hyperbole / hyperventilation, support the notion of why issuing UK 'tornado watches / warnings' is a thankless (and probably 99% inaccurate, locally) task, because most people totally miscontrue them. Essentially, its like issuing a lightning warning devoid of any specific location that will get whapped. I still think the "squally, perhaps damaging winds" style of warning remains the most logical route to cover tonight's sort of hit-or-miss windy / wet set-up.

[sammie]

Don't worry, this isn't a Gloucestershire exclusive. :lol: Our forecaster for the BBC Midlands Today mentioned the risk of (Oh god, here goes) 'mini' tornadoes across the West Midlands. I'm sure most regional forecasters across southern regions of the UK are mentioning for the possibility of tornadoes as the strong CF progresses eastward during tonight into tomorrow. Our forecaster also said not to get excited. Yeah, like I'm getting excited! :ph34r:

I'm getting excited and I don't even live anywhere near the Gshire! :lol: I'm just majorly interested in seeing how this turns out because I've never really seen a set up like it! Then again...I've not being doing this all this long.

I've totes done the wrong degree :lol:

[Nick F]

Well, nice to see the convective thread have some good discussion going on and thanks to Ian for his contributions.

Haven't had a great deal of time to look at tonight's potential, but a look at 12z GFS paramaters for severe weather all suggest favorable kinematic environment for an active cold front with potential for tornadoes to form and also damaging convective wind gusts to 70mph as strong LL jet winds lower to the surface in downdrafts ... anyway, have issued a MODERATE risk for much of England and Wales for tonight until 0600hrs:

http://www.netweather.tv/index.cgi?action=convective;sess=

[West Sussex Kate]

This is looking very exciting!!!!! The weather has been crazy these past few weeks first the storm force winds in the South, then the TERRIBLE floods in Cumbria and not to mention the constant rain we have had these past few weeks. The warmest winter I can remember..... It wouldn't suprise me that tonight is yet another *freak* event.

Edited November 24, 2009 by Westsussex1

[dogs32]

Ok..... thanks. Had not seen this. And everything you've cited here, including public responses and associated hyperbole / hyperventilation, support the notion of why issuing UK 'tornado watches / warnings' is a thankless (and probably 99% inaccurate, locally) task, because most people totally miscontrue them. Essentially, its like issuing a lightning warning devoid of any specific location that will get whapped. I still think the "squally, perhaps damaging winds" style of warning remains the most logical route to cover tonight's sort of hit-or-miss windy / wet set-up.

lol..Yes I know.

I had my next door Neighbours banging on the door late this afternoon asking OR telling me we are going to get a Tornado.

Because of the paper and the comments or quote's made on it.

After telling him it's ONLY a possability because of current weather setup.

Though saying all of this it is interesting weather if a Twister did make land.

Or near Dymock

Though hopefully in some field....

Latest radar looking more interesting and heavy precip out West of Cornwall

Edited November 24, 2009 by dogs32

[NL]

Ok..... thanks. Had not seen this. And everything you've cited here, including public responses and associated hyperbole / hyperventilation, support the notion of why issuing UK 'tornado watches / warnings' is a thankless (and probably 99% inaccurate, locally) task, because most people totally miscontrue them. Essentially, its like issuing a lightning warning devoid of any specific location that will get whapped. I still think the "squally, perhaps damaging winds" style of warning remains the most logical route to cover tonight's sort of hit-or-miss windy / wet set-up.

Totally agree that tornado warnings in the UK would more than likely stir-up hysteria among the majority of the public who will have visions of the monsters they see on programmes like 'Stormchasers' sweeping across the US. Most folk dont realize that the UK have more tornadoes than anywhere else to land mass ratio although most are

'weak'. Maybe when the UK radar network goes 'doppler enabled' will the likelyhood of a tornado be realized in certain locations but like in the US you only get a 10-15min warning.

[West Sussex Kate]

The serve weather looks like it might hit here about 1am ? *yawn* try and stay awake.

Edited November 24, 2009 by Westsussex1

[sammie]

The serve weather looks like it might hit here about 1am ? *yawn* try and stay awake.

That squall line is starting to get more intense on the radar. I take it thats where the bulk to tonights convective activity will be as it moves through?

[Harry]

Sorry if I am being dippy, but how does an ANA CF differ from a regular CF? I notice on Ian's post it states 'rear sloping'...does this mean effectively, that where normally a WF is rear sloping ( like a '/') the CF takes on this form?

[weatherobsuk]

Some inbounds to DUB (EIDW) reporting turbulence around FL150, aswell as stong gusts in/around the airfield. Makes for good listening on the Liveatc site.

I'd expect as the Front develops even more some of the medium-higher routes may be affected briefly by upper air turbulence. Right now it seems the area in question is from 5000ft-15000ft.

[BrickFielder]

Some suggestion of line convection on the radar now.

700hpa vertical velocity charts hint at the amount of lift in the lowest layer.

This chart shows the marked wind convergence at the front.

[tornadomanuk]

That squall line is starting to get more intense on the radar. I take it thats where the bulk to tonights convective activity will be as it moves through?

Yes defiantly starting to form a very pronounced line just off the coast of Cornwall and just in land of the West coast of Wales.

[TonyH]

The thin squall line developing nicely as it crosses Pembrokeshire and should be here soon after 2030!

Severe gale gusts here ahead of this feature, rain still only light.

[sammie]

Yes defiantly starting to form a very pronounced line just off the coast of Cornwall and just in land of the West coast of Wales.

Yip I've managed to pick it out on the radar. Though it seems to be getting a bit messy as it comes ashore.

[Stuart]

it going to be close i hope i see some storms later

[dogs32]

wind realy picking up here and on radar the rain seem's to be moving fast East.

Camera ready just in case

[Ian Fergusson]

Maybe when the UK radar network goes 'doppler enabled' will the likelyhood of a tornado be realized in certain locations but like in the US you only get a 10-15min warning.

I think many are already radiating using doppler but you'll not see this on the public feed. At least a fair proportion of the UKMO network are doppler enabled I believe, including the likes of Cobbacombe Cross, Dean Hill, Chenies, Thurnham, Clee Hill, Hill of Dudwick and some others too from memory. I'd have to check with UKMO. But their advantageous use in accurately nowcasting / flash warning for non-supercell (= the vast majority of) UK tornadic events is clearly a matter of debate and dubiousness. Yes, they'll help isolate the suspect squall lines and cells as they develop, but you can't compare this to the very different US set-up, both meteorologically (predominantly mesocyclones forming in generally well-forecast synoptic environments of ca. 24-hr lead-times), visually (aided by vast horizons/skyscapes and a network of able NWS storm spotters, chasers, local newmedia and some all-too-helpful straight highways) and broadcast-wise (local TV and other warning media on-air virtually all the time, with TV weathercasts holding a major stake at the very apex of TV running order 'premiums').