Storms and Convective discussion - 28th July 2019 onwards

[Weather-history]

Some lightning activity across Ireland recently.

[chapmanslade]

4 hours ago, Flash bang flash bang etc said:

I really dunno, estofex haven’t issued anything (which in itself isn’t too much of an issue) but neither have the UKWW peeps - which makes me think what we see developing out in open water is just a cruel tease

Well estofex don't always issue forecasts if there isn't anybody to do it. There is plenty of activity over Spain to justify one if there were.

[Another Kent clipper]

Is that us done for today then?

[Flash bang flash bang etc]

2 hours ago, chapmanslade said:

Well estofex don't always issue forecasts if there isn't anybody to do it. There is plenty of activity over Spain to justify one if there were.

Well UKWW just came on board with potential for tomo. Don’t know about tonight yet... maybe nowt

[chapmanslade]

1 hour ago, Another Kent clipper said:

Is that us done for today then?

If there is to be anything it hasn't even started yet !

[Flash bang flash bang etc]

13 minutes ago, chapmanslade said:

If there is to be anything it hasn't even started yet !

I think some activity will probably kick off in the SW over the next 2 hours. From there storms may pick up some energy in the channel and over France, where these have a chance of moving northwards and eventually into southern and central parts of the UK through the second part of the night.

Think anyone around Southampton and the IOW is likely to at least get some elevated flashes, maybe more. As Sunday gets underway and the Sun comes up it’s going to be more inland where we could see some thunderstorms develop.

Tony Gilbert at UKWW cites the Wash as a particularly good spot for more organised activity - but as always the UK can spin surprises on anyone, so don’t get too excited until storms have actually begun somewhere...

Edited September 21, 2019 by Flash bang flash bang etc

[Zak M]

2 minutes ago, Flash bang flash bang etc said:

 As Sunday gets underway and the Sun comes up it’s going to be more inland where we could see some thunderstorms develop.

Where abouts inland?

[Mapantz]

12Z UKV doesn't look particularly inspiring over night in the South, apart from a few showers East of the IoW after 3am. Maybe some imbedded lightning if you're lucky, but certainly going to be scattered.

[Zak M]

There's a nice little storm on the coast near Wales. Hoping for some developments soon in the south.

[Flash bang flash bang etc]

I know it’s overseas but that Corsica storm is an absolute beast

 

[Zak M]

Something is happening 

[MP-R]

Just had a rumble of thunder here. Cell nearby.

[Wilxy]

Radar looks "interesting"!

[WeatherWatchmanG]

900 strikes in last minutes unless I'm reading it wrong is unheard-of?

[AMeltedFlake]

Do lightning detector sites struggling to register cloud to cloud strikes? Looks like some intense showers in the south!

[WeatherWatchmanG]

4 minutes ago, AMeltedFlake said:

Do lightning detector sites struggling to register cloud to cloud strikes? Looks like some intense showers in the south!

Hardly intense enough for thunderstorms, they can struggle but they aren't struggling.

 

[AMeltedFlake]

3 minutes ago, WeatherWatchmanG said:

Hardly intense enough for thunderstorms, they can struggle but they aren't struggling.

 

You're correct, they dont seem to be electrifying, although the radar is apparently maxing out at rainfall amount. Not sure if they'll pick up tonight whilst moving north. 

[WeatherWatchmanG]

7 minutes ago, AMeltedFlake said:

You're correct, they dont seem to be electrifying, although the radar is apparently maxing out at rainfall amount. Not sure if they'll pick up tonight whilst moving north. 

I'm on netweather radar app other than Dorset coast which maybe reaching 96mm an hour the rest is well below and not even close to maxing out the scale used.

 

And here we go Weymouth just now 2 strikes just moments after I said the rain levels. So I honestly can't see energy unless more intense pockets of rain are being developed behind these showers.

Edited September 22, 2019 by WeatherWatchmanG

[MP-R]

Have already had a few rumbles of thunder from a cell that was just red on the radar so they don’t need to max out on rainfall scales or show all strikes on the lightning map.

[WeatherWatchmanG]

Just now, MP-R said:

Have already had a few rumbles of thunder from a cell that was just red on the radar so they don’t need to max out on rainfall scales or show all strikes on the lightning map.

Possibly but it's not what's expected at 2am let's see my app I've got premium on reckons between 7am and 11am worst of the storms in the south and east.

[AMeltedFlake]

12 minutes ago, MP-R said:

Have already had a few rumbles of thunder from a cell that was just red on the radar so they don’t need to max out on rainfall scales or show all strikes on the lightning map.

I think the cell that you've just had is heading towards me! Let's see if it's still rumbling...

[matt111]

Lightning to the east of here just now. 

[Spikecollie]

Some pretty intense rainfall over the IOM and the north of Eire. Some strikes showing up in the south of the UK.

[Mapantz]

A large downpour woke me. 107mm/hr rainfall rate. 2.8mm falling in 3 minutes.

[Allseasons-Si]

I am surprised that @Summer Sun hasn't posted from CW this evening

https://www.convectiveweather.co.uk/

Day 2 Convective Outlook

VALID 06:00 UTC Sun 22 Sep 2019 - 05:59 UTC Mon 23 Sep 2019

ISSUED 21:09 UTC Sat 21 Sep 2019

ISSUED BY: Dan

A complex pattern on Sunday, with several areas of potential interest. An instability axis will straddle a line from SW Scotland - Midlands - SE England first thing on Sunday morning, associated with a tongue of relatively high Theta-W. This zone will continue to nudge northeastwards through the day, which combined with subtle forcing aloft will allow clusters of elevated showers to develop ahead of the cold front - some capable of producing sporadic lightning. However, confidence is not particularly high as to how much lightning activity may occur given marginal CAPE and fairly marginal mid-level lapse rates, and so this scenario is treated with a low-end SLGT over northern and eastern England.

 

The cold front will be marked by a zone of showery rain from Northern Ireland - Wales - SW England first thing on Sunday morning, and this too will nudge northeastwards through the day. However, its slow motion will eventually allow a favourable overlap with strong forcing aloft on the forward side of the approaching Atlantic upper trough, which combined with a marked dry intrusion in the mid-levels could lead to an increase in deep convection along the leading edge of the cold front by noon and through the afternoon hours. The risk of lightning will therefore affect similar areas to the earlier elevated showers already covered by a SLGT.

 

Behind the cold front, the main upper trough axis will cross Ireland and SW Britain during the afternoon hours. The associated cool air aloft atop warm seas and diurnal heating inland will encourage scattered showers to develop, some weakly-electrified. Two low-end SLGTs have been introduced to cater for this risk over SE Ireland and SW England / S Wales.