Convective / Storm Discussion - 8th September onwards 2013

[dogs32]

Good to see you again Pat, hope life's treating you well

 

Tomorrow could be a lively one - this from the NMM

 

tomorrowstorm.png

thx Pual...missed it...but due to circumstances ...still...lololol...not sure if usa or uk is my home......ive been spoilt with storm...BUT......i miss my English folk truly.....here to Nov-DEc..........missed Netweather

[NUT]

It's not thundery but there's a pretty intense burst of rain over us now

[Jane Louise]

u always make me smile with your ethusism wits,,,,, TS.....try to be on more....got camera ready just in case

As you know I've never been lucky with storms lol  every storm season I live in hope but still nothing happens... but I never give up and one day I know its gonna happen, You wait and see Pat  

[dogs32]

As you know I've never been lucky with storms lol  every storm season I live in hope but still nothing happens... but I never give up and one day I know its gonna happen, You wait and see Pat  

it will promise.......gonna happen...your see.....keep an eye tomorrow..good chance like Paul said charts showing good potential

 

if not tomorrow....it will happen  always does in cycles..always be optomistic..

 

a bit surprised there aint more people on here  watching this

Edited October 2, 2013 by dogs32

[Jane Louise]

it will promise.......gonna happen...your see.....keep an eye tomorrow..good chance like Paul said charts showing good potential

 

if not tomorrow....it will happen  always does in cycles..always be optomistic..

Always the Optimistic I am Lol I really have a good feeling now about tomorrow..whenever you promised before all those years ago they did actually happen. Yay, roll on  tomorrow. I'm awaiting the  forecast from Estofex at the moment.Wonder what time it will be tonight.

[dogs32]

Always the Optimistic I am Lol I really have a good feeling now about tomorrow..whenever you promised before all those years ago they did actually happen. Yay, roll on  tomorrow. I'm awaiting the  forecast from Estofex at the moment.Wonder what time it will be tonight.

its always a good direction from the south plume....i will keep an eye through out tonight.......did u see the other month N/E.. now that was a supercelll...skirted here Gloucester West......lightning was like Texas no kidding.....though gutted as it headed north towards Coventry,notts  ect...around 3---4am...consistent lightning..anyway i will be quiet.........looking at radar 

Edited October 2, 2013 by dogs32

[Jane Louise]

its always a good direction from the south plume....i will keep an eye through out tonight.......did u see the other month N/E.. now that was a supercelll...skirted here Gloucester West......lightning was like Texas no kidding.....though gutted as it headed north towards Coventry,notts  ect...around 3---4am...consistent lightning..anyway i will be quiet.........looking at radar

Ahh yes, many a times these storms have been so close to me the sky has looked evil and I've had the camera ready also  been glued to the NW radar and the damn things always get so close then head off NE lol

[dogs32]

lots of sferics off south ireland......nice beafy storm north spain

[Team Jo]

Ooh. I'm excited, new camera lens and a day off work tomorrow. Just hoping the energy stays high enough to keep it sparky! Good luck everyone!

[A.J]

nice one jane....................heres hoping...keeping eyes open for toniight early hrs

bloody hell, talk about a blast from the past, it's NWeather's 'lightning Timmer!".....nice to see you back Pat, just in time for a late in the season MCS...

[Nick F]

Storm & Convective Forecast

Issued 2013-10-02 21:32:19

Valid: 03/10/2013 0000z to 04/10/2013 0600z

  THERE IS A RISK OF THUNDERSTORMS FORECAST

Synopsis
An amplified upper-level trough and surface low pressure system stretching from Iceland down to NW Iberia will slowly edge eastwards towards western UK on Thursday. A long-draw southerly flow will be in place across the UK, with increasingly warm/moist air advecting north in warm sector during the day, with a cold front moving in from the SW during the evening, clearing the east coast by midnight.
 
... SW ENGLAND, WALES, IRELAND/N IRELAND and IRISH SEA ...
 
Warm/moist air advection and continued height falls/large scale ascent with approaching upper trough from the west will continue to bring further heavy showers and isolated thunderstorms overnight and early morning in the above areas, though convection looks to wane with time with dynamic rainfall tending to take over during Thursday.
 
... S ENGLAND, S WALES, THE MIDLANDS, E ANGLIA and LINCS THURS ...
 
A summer-like plume of high wet-bulb potential temperatures (theta-w values of 16c+) will advect north from France across Sern Britain during Thursday afternoon and evening. This warm/moist airmass will be characterised by steep low to mid-level lapse rates and will become increasingly unstable as mid-levels cool and forcing for ascent arrives with approaching cold front and trailing upper shortwave trough moving up from the southwest during the evening.  GFS indicated MLCAPE values approaching 600-700 j/kg  in the afternoon/evening.  Therefore, it seems thunderstorms will develop and drift north/northeast, though they will likely be rooted above the boundary layer – i.e. elevated in nature.  Strengthening mid to upper southerly flow will allow any storms to organise into multicell or perhaps small mesoscale systems capable of producing high rainfall totals in a short space of time – bringing the risk of localised flooding. Also storms may produce hail, gusty winds and frequent CG lightning.

 

Issued by: Nick Finnis

 

Edited October 3, 2013 by Nick F

[Jane Louise]

I've been checking  the Met office rain radar for the past hour and it's been showing heavy rain over my area, I've been outside to check a couple times and there's been nothing at all! I'm wondering if its anaprop.

[Bobby]

Some torrentrial rain here over past few hours, some very large drops. Doesn't seem to be any electrical activity about though, hopefully tomorrow.

[jello]

Tornado in Galway this evening, Structural damage to building and damage to trees, power supplies also affected. 

 

Video https://www.facebook.com/photo.php?v=661032670581800&set=vb.100000252195264&type=2&theater

 

 

Edited October 2, 2013 by jello

[Panayiotis]

From Ian just now:

W COUNTRY For the weather watchers, key tomorrow will be potential MCS developments running into SW and indeed further E; high PWAT values..

W COUNTRY Weather Watchers CONTD... with squally downdrafts from any MCS giving strong gusts and possible hail.

[Biggin]

 

Posted 7.38pm Weds

 

Moderate Risk of Elevated Thunderstorms Early Phase SW UK and Late Phase SE UK

 

A relatively low risk for categorised severe weather though certainly some potential for localised electrical displays.

 

A near 'Spanish Plume' scenario with a very elevated layer of theta expected to slide northward from the continent through Thurs. Looking at the forecast soundings it appears unlikely that any of this lot will be capable of becoming surface based. ML CAPE looks to start from around 700mb upwards. Spanish Plumes are typically very hard to predict timing wise. In this case even more so when the theta looks mixed in with the primary cold front then post frontal surface troughing. Some broad variation within the WRF and GFS models; WRF giving scattered thundery showers primarily early on across the SW whilst GFS concentrates the best instability much further east later in the day. If we look primarily at the GFS we see the strongest risk zone to be Herts through to Suffolk late evening. Whilst this region shows the strongest ascent between an elevated layer at 650mb and 500mb I am not sure if the increase in vertical shear at this level will have any significant effect in isolating any embedded storm cells.

 

http://www.ukweatherworld.co.uk/forum/index.php?/topic/99790-convective-outlook-thurs-3rd-oct-2013/

 

http://www.ukweatherworld.co.uk/forum/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=24759

 

Good luck all.

 

What time is "the late phase" JL ??

 

Edit     Sorry I see from Nicks post Thurs pm. Bring it on

Edited October 2, 2013 by Biggin

[Mapantz]

Tornado in Galway this evening, Structural damage to building and damage to trees, power supplies also affected. 

 

Video https://www.facebook.com/photo.php?v=661032670581800&set=vb.100000252195264&type=2&theater

 

That's a beaut of a structure! Thanks for posting that.  

 

I'm up very early tomorrow, a few things to do .. etc .. so i'm really interested in seeing the radar early on. There should be some good cloud formations appearing in the morning, might be worth looking up and taking some snaps & posting them (I can't due to using a TV webkit unfortunately) I hope many of you have some fun weather tomorrow. 

[poseidon]

Estofex looking very nice too...

 

 

 

Storm ForecastValid: Thu 03 Oct 2013 06:00 to Fri 04 Oct 2013 06:00 UTCIssued: Wed 02 Oct 2013 22:35Forecaster: GATZEN

A level 2 was issued for south-western France mainly for large hail and severe wind gusts.A level 1 was issued for western and central France, central and northern Spain, northern Portugal, southern British Isles, western Netherlands, and Belgium mainly for severe wind gusts, large hail, tornadoes, and excessive precipitation.SYNOPSISA cold and dry air mass has spread across most of Europe and low-level mixing ratio is below 9 g/kg from the North Sea to Italy and southern Turkey. Given weak lapse rates, CAPE is not expected over most places. Across western Europe, much better moisture is present that has been advected northward from the Atlantic Ocean and westward from the Mediterranean Sea. A tongue of rather well-mixed warm air will spread northward into France and surroundings ahead of an approaching Atlantic trough. QG ascend is expected as a short-wave trough moves north-east across Iberia, France, and the southern British Isles. Given the strong vertical wind shear, potential of severe thundestorms is rather high.DISCUSSIONSpain, France, Benelux, southern British IslesRich low-level moisture is present across France, sampled by latest Bordeaux sounding. This moist air mass is expected to spread into northern France and the southern British Isles on Thursday. Ample moisture is also present across the Atlantic west of Portugal and the western Mediterranean Sea. The flow will continue to advect the moist air mass onshore across Iberia and southern France. Although lapse rates are not too large, CAPE is present and weak capping has allowed for thunderstorms across Portugal along a cold front that spread into the Bay of Biscay during the night. Further east, steeper lapse rates and a stronger capping inversion are present.On Thursday, warm air advection will continue across France and the British Isles ahead of the Atlantic trough. The first thunderstorms will likely spread northward into north-western France and further into the British Isles until noon, where they will become gradually elevated. New storms are expected to initiate across Spain in the moist upslope flow. Some QG ascend can also assist in initiation as a short-wave impulse travels north-eastward in the noon hours. Later in the day, this short-wave trough is expected to increase the storm potential across eastern Spain, western and central France and the Benelux countries.In the strongly-sheared warm air advection regime with 0-6 km bulk shear in excess of 15 to 20 m/s and 0-3 km SRH around 100-200 m²/s², organized storms are forecast. Multicells and supercells capable of producing large hail are forecast. Especially in the afternoon and evening hours, large low-level hodographs and adequate low-level buoyancy are present, and tornadoes are forecast especially with isolated supercells. Strong tornadoes are not ruled out. The highest risk of severe storms is expected across south-western France, where capping will be rather weak and low-level wind shear will be strong due to backing winds north of the Pyrenee mountains. Severe wind gusts may also occur, especially with bow echoes forming from merging storms. Larger storm clusters and mesoscale convective systems can also produce excessive rain. The threat will decrease after sunset due to the boundary-layer stabilization.

 

 

[ZONE 51]

Very interesting period of weather coming up (already started for some) feels like August when we get the thundery plumes, well it is the same and quite impressive for October! and would be just as exciting any other time! Many storm forecasts out track back up the page and previous for lots of information / storm forecasts.

Edited October 3, 2013 by ElectricSnowStorm

[NO LONGER POSTING]

Brewing already...

 

Expected at 8:30

 

BIG downgrade on PPN rates on the NAE...

[Jane Louise]

It's looking very promising today and this time I'm sure I'll get a storm  wherever you may be  good luck and keep safe,  e.g .which includes no standing on top of hills in any fierce thunderstorms  or hanging from tops of trees with your camera trying to get lightning shots and getting stuck up there in a strong lightning storm with no one there to rescue you lol!  ( you know who you are  lol say no more)

[wimblettben]

Whats all this talk about thunderstorms?

 

It doesn't look very thundery out there at the moment. Its just overcast, drab and grey just like its been for the past month or so.

[Coast]

A lot to get through today and might as well kick off with UKASF:

 

 

 

Synopsis

 

Upper trough will drift northeast towards Britain; one the forward side, advection of an unseasonably very warm and humid airmass will occur from Biscay and Iberia, characterised by an elevated plume of high ThetaE. The approaching trough and surface fronts will allow destabilisation of this plume, resulting in convective activity.

 

Discussion

 

An area of showers/storms (elevated) will arrive across SW England from mid-morning onwards, initially active sferic-wise over the english Channel, but likely to weaken as it heads further inland. Nonetheless, prolonged downpours in PWAT of 30-40mm will significantly increase the risk of local flash flooding.

 

As this complex crosses into the West Country, south Wales and the West Midlands, there are suggestions that sferic activity may increase through the afternoon hours as the ThetaE ridge strengthens, hence the inclusion of a SLGT area here to cater for this potential increase in lightning activity, albeit probably weakening again towards evening as it continues to track northeastwards across the Midlands/East Anglia.

 

Most models then simulate a second round of elevated showers/thunderstorms across southern counties towards evening, running northeast towards coastal parts of East Anglia and the southern North Sea during the late evening and early hours of Friday. Given strong ThetaE gradient/ridge and 600-800J/kg MLCAPE, this appears to have better potential for more widespread/frequent lightning activity, and it is possible we may consider to upgrade Kent and East Sussex to a MDT if conditions still look favourable during Thursday. These cells may produce hail up to 2.0cm in diameter, and strong, gusty winds. While the majority of showers/storms will be rooted above the boundary layer, if a surface-based storm could develop then it may benefit from sufficient DLS and LLS, with perhaps supercell-like characteristics and a potential for a tornado.

 

A general increase in sferic activity is anticipated as showery rain exits into the North Sea during the evening hours, hence the inclusion of coastal areas in a SLGT from Yorkshire down to Norfolk. Lightning activity is possible elsewhere within the ISOL, particularly over the Irish Sea and eastern side of Ireland, but coverage is not expected to be large enough for an upgrade to SLGT (as things currently stand).

 

 

 

[Coast]

Aviation significant weather chart has potential slightly to the East of most models:

 

[A.J]

Whats all this talk about thunderstorms?

 

It doesn't look very thundery out there at the moment. Its just overcast, drab and grey just like its been for the past month or so.

Give it chance Ben

Things are certainly brewing up over north west France, ugly red echoes on the radar tracking into the Channel towards the English coast