Convective/Storm Discussion Thread - 1st June onwards

[Flash bang flash bang etc]

28 minutes ago, Surrey said:

Lift off? Come on little new cell, let's see if it's time to party or you are just playing a joker card.. 

I’m seeing small (read: tiny) clouds which quickly disappear. It’s not even hazy anymore  

Practically clear skies near Farnham

[Derbyshire_snow]

18 minutes ago, The PIT said:

Pathetic attempt here. Weak Thundery shower producing 0.2mm of rain so still on for one of the driest Julys on record.

So still storm free here just two thundery showers this year and weak ones at that.

Tomorrow is a dead duck as well. GFS and local forecast both say  a dry hot day.

This rain must be ridiculously localized as i am just a few miles from you and we have had no rain at all.

[Mapantz]

Just now, LightningLover said:

Being on the East Sussex coastline, should I give in and call it a night, or wait a bit longer?

Do you not have any lightning apps on your phone? You can set alarms to be triggered if lightning is recorded at a distance you set. I always used to do it if I was in with a shout. I'd set a loud tone for the alert, it would always wake me up.

[TJS1998Tom]

Still early yet, had a few good bright flashes. I reckon it'll be more interesting in a few hours or tomorrow evening for the big stuff

[LightningLover]

1 minute ago, Mapantz said:

Do you not have any lightning apps on your phone? You can set alarms to be triggered if lightning is recorded at a distance you set. I always used to do it if I was in with a shout. I'd set a loud tone for the alert, it would always wake me up.

Eh, I suppose I could, but I like to experience the buildup on here and in real life, prior to a good storm!

[Flash bang flash bang etc]

Think that Woking cell is dissipating. Moving too quick even if it does fire up anyway, we need something in the channel  - or at least along the coast - to get going

[SenlacJack]

3 minutes ago, LightningLover said:

Being on the East Sussex coastline, should I give in and call it a night, or wait a bit longer?

To be honest I really don't see any prospects at all for our area tonight.

[Harry]

Sky has taken a rapidly different complexion here. It is awash with fast moving mid level cloud. From underneath it’s hard to make out shape/form but the moon is suggestive of AcCas or similar intermingled. Somewhere I suspect will go bang around here very soon. Does look quite reminiscent of July 2015!!

[Allseasons-Si]

Do i see a CZ on the latest from http://www.xcweather.co.uk/

i have seen a few flashes to my east but not looking promising here at the moment but i know how things can quickly deteriorate so i will keep a watch for a bit longer,say until 4am

 

[Flash bang flash bang etc]

1 minute ago, SenlacJack said:

To be honest I really don't see any prospects at all for our area tonight.

It’s not like they put us under a moderate anyway. Really wouldn’t bank on July 2015 at any rate. Shame though - would have been nice

[Flash bang flash bang etc]

2 minutes ago, Allseasons-si said:

Do i see a CZ on the latest from http://www.xcweather.co.uk/

i have seen a few flashes to my east but not looking promising here at the moment but i know how things can quickly deteriorate so i will keep a watch for a bit longer,say until 4am

 

Lol - do I drive to Banbury for 4am on a chance this might come off?

Might just go home and sit in bed watching the radar... 

[Robert Lewis]

this cell over by Bracknell seems to have a chance of delivering something, seemed to build up relatively quickly too, already past here before anything comes of it though.

[Cheshire Freeze]

E and NE England look to be in for a right treat storm wise tomorrow evening...

[ChezWeather]

6 hour accumulation from EURO4 tomorrow afternoon along with Arome Hires, both showing the East coast / the North sea as the place to be. Only the NMM (NW SR) shows the precip inland 

 

[Harry]

I’m going to try to get some shut eye but it’s bloody difficult - 24-25C outside and add at least another 5C inside. Have two fans on full blast and it’s barely keeping me sweat free let alone cool. Meanwhile sky continues to fill with cloud and a now taking the bronze tinge I always have associated with pending rain...here’s hoping I get woken up

[Flash bang flash bang etc]

Bugger me just realised where I am... thought I was near Farnham and i’m actually in Liss 

[Norfolk Sheep]

Would prefer Friday night if possible. Day time storms are so wasteful, all that lovely lightning....

[LightningLover]

Right, time for some kip methinks. But that's easier said than done in this sweatfest!! Goodnight all, My windows and curtains are all open, so any cheeky t-stroms are welcome to wake me up! IMO, tomorrow looks much better from an IMBY standpoint, but i'm still amazed by CW's first ever HIGH risk zone. Good luck to everyone over the next 36 hours or so!

[Nick F]

Storm & Convective Forecast

Issued 2018-07-26 22:50:00
Valid: 27/07/2018 00z to 28/07/2018 00z

THUNDERSTORM OUTLOOK - FRIDAY 27TH JULY 2018

Synopsis

Large long-wave upper trough to the west of the British Isles will become increasingly negatively-tilted (NW-SE aligned) as the trough pushes east and comes up against blocking high over Scandinavia. Meanwhile, low pressure system to the west of Britain will expand eastwards, with a cold front lying from western Scotland down across Wales and SW England at noon Friday pushing east from Wales while stalling across western Scotland, to lie from Lancashire to Isle of Wight by midnight. A hot, humid and very unstable airmass to the east of this frontal boundary will fuel the development of thunderstorm, perhaps locally severe across eastern England.

A low to mid-level southerly flow ahead of cold front arriving in the west will transport large amounts of moisture north towards the eastern side of England and eastern Scotland – characterised by high theta-w (wet bulb potential temps) of around 16-18C.

… EASTERN ENGLAND and EASTERN SCOTLAND EARLY HOURS …

Corridor of dry mid-level air punching north on eastern flank of southerly jet across the west will initially destabilise the western edge of the theta-w plume across the east in the mid-levels overnight … this combined with a few subtle shortwaves running north will support ongoing elevated storms across NE England and E Scotland during the night before eventually clearing away. Also some models support development of scattered elevated thunderstorms in the early hours across parts of central S and SE England, these storms then tracking N through the morning across E England and eventually E Scotland.

… SE ENGLAND and E MIDLANDS FRIDAY DAYTIME …

In wake of early morning elevated thunderstorms spreading north, there could be a dry interlude, before perhaps further elevated thunderstorms spread N across SE England and E Midlands through the afternoon and evening, as the western edge of theta-w plume continues to destabilise in the mid-levels. These localised storms may bring a risk of localised flooding and frequent cloud-to-ground lightning.

… NE ENGLAND, LINCS, E ANGLIA DAYTIME …

Further east of the mid-level activity, a greater chance of sunny spells developing towards NE England, Lincs and East Anglia will allow hot or very hot surface temperatures to develop, reaching the mid-30s Celsius across E England and E Anglia. This strong heating of very moist surface airmass, characterised by dew points of 17-18C, beneath steep lapse rates of elevated mixed (EML) layer aloft, is forecast to yield CAPE values of 1500-2000 j/kg. This strong instability and vertical deep layer shear increasing to 30-40 knots will support the development of organised storms, likely multicell cluster and perhaps a few supercells, forming along sea breeze convergence towards the east coast or from orographic forcing over hills, and capable of producing hail to 3cm in diameter, excessive and intense rainfall leading to flash-flooding and strong / perhaps damaging outflow winds locally. There is potential along the breeze confluence for updrafts to rotate strongly enough to produce a tornado too, given sufficiently low LCLs (lifted condensation level) given moist surface airmass. Therefore, have issued a SEVERE storm risk area along coastal eastern England.

… THE WEST …

Cold front arriving from the west over the Irish Sea in the morning will likely bring pulses of heavy and perhaps thundery rain, with occasional isolated lightning, north along it as it moves in across SW England, Wales and western Scotland during the day, before reaching central S England, Midlands and NW England in the evening. A second cold front arriving from the west across SW England and approaching S Wales by late evening will have a surge north of warm, moist and unstable air ahead of it, with CAPE values of 600-900 j/kg forecast, strong jet aloft parallel to front moving east and deep layer shear of 40-50 knts may favour storms forming linear bowing line segments, capable of isolated damaging winds, hail and brief intense rainfall leading to flash-flooding. Have issued an area for strong storms here.

Issued by: Nick Finnis

Edited July 26, 2018 by Nick F

[Allseasons-Si]

7 minutes ago, Flash bang flash bang etc said:

Lol - do I drive to Banbury for 4am on a chance this might come off?

Might just go home and sit in bed watching the radar... 

Lol

just stating the wind direction but could be a good bet

[Biggin]

22 minutes ago, Harry said:

Sky has taken a rapidly different complexion here. It is awash with fast moving mid level cloud. From underneath it’s hard to make out shape/form but the moon is suggestive of AcCas or similar intermingled. Somewhere I suspect will go bang around here very soon. Does look quite reminiscent of July 2015!!

Round here ??

[Flash bang flash bang etc]

Edited July 26, 2018 by Flash bang flash bang etc

[Mesoscale]

Just now, Flash bang flash bang etc said:

I know of wishful thinking but Anoprop is up there lol 

[Harry]

Just now, Biggin said:

Round here ??

Perhaps not locally literally, I had in mind London region and Home Counties and westwards/northwards.

Some models have suggested we could nick something or if not then act as a breeding ground. I’ve witnessed too many times models pointing action further west despite sitting under an area of high instability, only for it to go bang here too.

The rampant humidity and rapidly changing sky in the past hour or so makes me think we are in for a decent chance. But so far no where in southern England has any spoils to speak of...yet

[tomp456]

Night all.

see y’all on the next bust