Convective / Storm Discussion Thread - 31st May 2017 onwards

[Mercury Rising]

8 minutes ago, Boro Snow said:

Game over for the north east 

tis a shame I was really hoping for a repeat performance as like this morning  

[Muffelchen]

Just now, SarahWxm said:

Bloody disappointing isn't it. I had a feeling I would jinx things being here and yes think wrexham did have slightly more! Grr. Whereabouts from Wrexham are you? I'm from Rhosddu. 

Acre Fair but left when I was 2  Been here for 13 years now.....  Good place for storms but not last year (or this yet...).

[Weatherman662]

Same here .

 

[SarahWxm]

2 minutes ago, Muffelchen said:

Acre Fair but left when I was 2  Been here for 13 years now.....  Good place for storms but not last year (or this yet...).

Aah yes Acrefair. I have a lot of family in Leeds and castleford so have links with Yorkshire. I always thought up here was good for the storms sovwas hopeful, but my good old jinxing behaviour soon sorted that out lol

[Muffelchen]

Just now, SarahWxm said:

Aah yes Acrefair. I have a lot of family in Leeds and castleford so have links with Yorkshire. I always thought up here was good for the storms sovwas hopeful, but my good old jinxing behaviour soon sorted that out lol

Ha! Such is the way sometimes! Maybe we'll get something overnight but I'm off to bed now. Found it interesting everyone was saying how muggy it is - certainly not here eh? Oh well, hope you see sommet while your over here 

[Summerstorm]

2 minutes ago, SarahWxm said:

Aah yes Acrefair. I have a lot of family in Leeds and castleford so have links with Yorkshire. I always thought up here was good for the storms sovwas hopeful, but my good old jinxing behaviour soon sorted that out lol

One thing that can be said is that Wrexham is terrible for storms can't remember the last time we had a good one the last few we've had were like 5 lightning bolts and a bit of rain and thunder.

[SarahWxm]

3 minutes ago, Summerstorm said:

One thing that can be said is that Wrexham is terrible for storms can't remember the last time we had a good one the last few we've had were like 5 lightning bolts and a bit of rain and thunder.

Yeah Wrexham isn't the best. Had a whopper a couple of years ago with fab lightning, but been pretty scarce apart from that. Had some crackers in the 90's.  Every time I get my hopes up I get let down. The last ace one was in Majorca and I waited so long for it I fell asleep and missed half of it haha

Edited June 21, 2017 by SarahWxm

[RichmondWeather]

It seems to be raining a bit in my area (SW London)

[Mesoscale]

Shower west of Oxford, can you imagine if it went mental. 

[alexisj9]

2 hours ago, StormChaseUK said:

Wonder if they have got it wrong, and the weather doesn't actually turn cooler yet

I hope not, it's been to hot. 

[Mapantz]

It's certainly all changed here. Down to 16.6 °C and there's fog.

[Flash bang flash bang etc]

1 minute ago, Mapantz said:

It's certainly all changed here. Down to 16.6 °C and there's fog.

Thunderfog!

[Frosty hollows]

5 minutes ago, Mapantz said:

It's certainly all changed here. Down to 16.6 °C and there's fog.

Fog!!! Man alive, it's still 24 C here and that's ourside. Indoors is a fair bit higher. another crap night's sleep

[Nick F]

Storm & Convective Forecast

Issued 2017-06-21 23:03:55
Valid: 22/06/17 06z to 23/06/17 06z

CONVECTIVE / STORM FORECAST - THURSDAY 22ND JUNE 2017

Synopsis

Shortwave upper trough, to the west of Ireland Wednesday evening, will move east across southern Britain during Thursday ahead of upper low near Iceland. At 12z Thursday, a surface cold front on the rearside of this upper trough will lie roughly North York Moors to Lands End at 12z Thursday, with an unstable warm humid airmass ahead of it across SE UK. an upper cold front clearing Kent and East Anglia east coast. By 00z Friday, the surface cold front has moved well to the east over the near continent, with cooler and more stable airmass following across the UK.

DAY 1 CONVECTIVE FORECAST – UNTIL 06z THURS

… N ENGLAND and E SCOTLAND …

Thunderstorms that broke out across central and S Scotland along with N England this evening, in association with ascent of warm moist plume along its northern edge, should eventually clear away east into the North Sea in the early hours of Thursday. These storms may still pose a risk of flash-flooding, hail, frequent lightning and strong wind gusts in the next few hours.

DAY 2 CONVECTIVE FORECAST – THURS 06Z – FRI 06Z

… SW and S ENGLAND, MIDLANDS, LINCS and E ANGLIA …

An upper cold front, marking the leading edge of colder air aloft associated with shortwave upper trough moving east in the morning will, in tandem with the shortwave, create forced ascent of warm and humid airmass present across S, central and E England over recent days. This forcing will likely form a linear band of thunderstorms, that will track east during the morning across the above areas, Unidirectional winds from the surface to 300mb, but strong aloft, will organise storms into a broken linear squall, with some bowing line segments, capable of producing locally strong wind gusts. 40-50 knots of deep layer shear and moderately unstable warm humid airmass could favour some locally large hail too, perhaps isolated up to an inch. Flash-flooding from sudden and  intense downpours is also a concern, given PWAT (Precipitable Water) values forecast of 30-33mm. Storms could also produce frequent cloud-to-ground lightning too. Have issued a SLIGHT risk for flash-flooding, strong wind gusts (40-50mph) and large hail. These storms should clear away east into the N Sea/near continent in the afternoon.

… N ENGLAND, N MIDLANDS, LINCS …

Another area of storms could develop during the afternoon along the surface cold front clearing east across the above areas, forcing for ascent greater along the front here given better upper support. Vertical shear will be fairly weak, but storms may still produce locally intense rainfall leading to flash-flooding and maybe an isolated incidence of large hail – so have warranted a MARGINAL risk for this area. These storms clearing away into the N Sea early evening.

[Ben Sainsbury]

The dewpoint is the same as the temperature here, is that unusual?

[Mesoscale]

Does this setup remind you of the Wimbledon setup? I can't remember what year it was but storms where forecast for the day but none materialised but the next say storms broke out widespread across the SE when they were not forecast to? 

[Mapantz]

11 minutes ago, Frosty hollows said:

Fog!!! Man alive, it's still 24 C here and that's ourside. Indoors is a fair bit higher. another crap night's sleep

I've just been out for a wander, its actually sea mist that has come this far inland. It does it on rare occasions. Despite a nice breeze now, its eerily orange outside. 

[Mapantz]

4 minutes ago, Ben Sainsbury said:

The dewpoint is the same as the temperature here, is that unusual?

That would indicate total saturation. 100% RH - Not highly unusual, but the sensor might be damp?

[Frosty hollows]

Outside isn't too bad. If it was the weekend I'd get the laptop on, sleeping bag out and do Glasto on Thames!

[matt111]

Just now, Mapantz said:

I've just been out for a wander, its actually sea mist that has come this far inland. It does it on rare occasions. Despite a nice breeze now, its eerily orange outside. 

Same here. I noticed the wind has increased which is probably why it's happened.

[Harry]

5 minutes ago, Mesoscale said:

Does this setup remind you of the Wimbledon setup? I can't remember what year it was but storms where forecast for the day but none materialised but the next say storms broke out widespread across the SE when they were not forecast to? 

27/28 June 2011 rings a bell. If I recall correctly, cold front was supposed to have cleared through so time earlier, however didn't reach the SE until early afternoon the next day. Temps reached 30-31C before storms erupted. I remember the lightning was frequent and unusually strong, with ear splitting thunder.

[Ben Sainsbury]

Just now, Mapantz said:

That would indicate total saturation. 100% RH - Not highly unusual, but the sensor might be damp?

According to XCWeather seems to be evident at various locations, but thanks anyway.

[Frosty hollows]

Just now, Mapantz said:

That would indicate total saturation. 100% RH - Not highly unusual, but the sensor might be damp?

My humidity has rocketed from 38 to 80 in2 hours . Yuk!

[Frosty hollows]

2 minutes ago, Ben Sainsbury said:

According to XCWeather seems to be evident at various locations, but thanks anyway.

Yep..according to xc dp = actual temp. Humidity = 100%

[Harry]

This was the day @Mesoscale