Storms and Convective discussion - June 2023

[Summer18]

Absolute crap if I’m honest today. It’s been humid and muggy for days and all we got was just overcast skies and what seemed like frontal rain, Rubbish. 

Edited June 18, 2023 by Summer18

[Allseasons-Si]

And here is the main course, I didn't edit the video in the end cos it was good all way though,...enjoy,...oh and sorry for swearing at the beginning,...just missed a beauty

some stills first,some of these in sequence

 

IC folk

CG fork

 

 

 

 

[Turquoise]

1 hour ago, Eagle Eye said:

Convective Outlook  

Sunday 23:00 - Monday 21:00

Overnight a few elevated showers with occasional lightning may occur behind the departing MCS, with the continued strong Theta-W. Energy is weak but there may be enough to spark a weak thunderstorm somewhere in the channel. Those should weaken by early morning hours. There may also be a few rumbles into the night from the storms currently pushing through the north of England but they should generally weaken and depart as the evening goes on.

As the surface heating kicks in, modest but in places strong bouyancy looks possible in the UK. Combine that lift with 600 J/KG of energy and we've got a slight risk day with scattered showers and weak thunderstorms possible in the UK.

Generally forcing is low (ish) relative to how much of it can be ingested by the storms and CAPE is too low to worry about the shear and hoe long the storms in the UK will last. Generally they'll be pulse-storms with a few longer-lived ones.

Turning attention to Ireland where CAPE in excess of 1,500 J/KG at the surface means thst storms can latch onto that bouyancy, providing vigorous convection. In the morning shear should be running parallel to the passing cold front out east, though its on the western extent of the shearing and so as it gets towards initiation in the afternoon, the shearing weaks to virtually non existant. So mainly pulse-storms look to be the mode of convection. The CAPE may be enough to produce clusters in some areas though.

A shortwave trough in the area, provides just enough forcing support for a moderate risk to be placed in Ireland. So a tentative low-end moderate has been placed in Ireland due to fairly good confidence of storm formation within that area, with the AROME being especially strong there.

Strong moisture and PWAT with low to the ground LCL's along with ample entrainment CAPE has meant that we've gone for a small severe risk for possible flooding in Ireland. Perhaps some small hail is also possible but unlikely to reach severe status.

Ireland has had a fantastic summer already for storms, Wales too.

[Eagle Eye]

A few time lapses from this evening with photos to go through as well. In no particular order.

 

 

 

 

 

 

 

 

 

 

[Cain]

I’m guessing those stray showers in south will be non electrical 

[Eagle Eye]

2 minutes ago, Cain said:

I’m guessing those stray showers in south will be non electrical 

Most likely yeah, can't rule out a sporadic strike or two but there's not much energy to go around now.

[alexisj9]

4 minutes ago, Cain said:

I’m guessing those stray showers in south will be non electrical 

So far they haven't been.

I have just seen a flash to my se, must be from those storms in France, cause there's nothing else anywhere. Amazing how far flashes can travel sometimes.

Edited June 18, 2023 by alexisj9

[Eagle Eye]

3 minutes ago, alexisj9 said:

So far they haven't been.

I have just seen a flash to my se, must be from those storms in France, cause there's nothing else anywhere. Amazing how far flashes can travel sometimes.

Yep, given the strength of the storms I would say point your cameras ready for sprites but I don't think many on this forum, especially in the SE has the right types of camera for sprites, no idea what you would need to be honest.

[Eagle Eye]

Non-edited image of the view I had of the shelf cloud or whatever it was earlier on the passing front edge I'm assuming of the north France MCS outflow.

[Norfolk Sheep]

45 minutes ago, Allseasons-si said:

And here is the main course, I didn't edit the video in the end cos it was good all way though,...enjoy,...oh and sorry for swearing at the beginning,...just missed a beauty

some stills first,some of these in sequence

 

IC folk

CG fork

 

 

 

 

Lucky so and so, I haven't seen anything like that since about 2015 (and that was in Holland....)

[TJS1998Tom]

Proper kicking off here, shame this wasnt the case at our end in the UK today, tempts looking to increase up to 25-28c again in the next week or so though so more chances of some thundery weather

 

[Allseasons-Si]

Just gone through my third and last clip,...no visible lightning but i didn't realise that there was a funnel cloud...

[Tamsin]

4 hours ago, london-snow said:

Absolutely hate this weather too hot and humid, No storms to reward this sultry endurance. 

What makes it more frustrating is the fact that our warm drizzle was part of the insane storm that was anchored to the French coast.

[Gordon Webb]

 

Day 1 Convective Outlook

VALID 06:00 UTC Mon 19 Jun 2023 - 05:59 UTC Tue 20 Jun 2023

ISSUED 06:25 UTC Mon 19 Jun 2023

ISSUED BY: Dan

Heavy rainfall over Scotland on Monday morning, associated with a pronounced shortwave, will gradually clear northwards trough the day - although there is scope for embedded elevated convection in eastern Scotland, feeding inland from the North Sea. Elsewhere, a bright and breezy day is anticipated underneath a weak, transient upper ridge. That said, diurnal heating will yield 500-900 J/kg MLCAPE over Ireland/Northern Ireland beneath the eastern flank of a cold pool aloft associated with the broad upper low/trough to the west over the Atlantic. As such, scattered showers and a few thunderstorms are likely here, especially during the afternoon and early evening hours. Showers/storms may become particularly focussed along a couple of marked SW-NE convergence zones, especially from Munster to mid-Leinster and perhaps another from Connacht into Ulster. Modest southwest flow aloft with a unidirectional wind profile will result in 15-20kts effective shear, allowing some cells to become somewhat organised and capable of producing hail potentially 1.0-1.5cm in diameter (sub-severe). The risk of flooding will be augmented by stronger steering flow than recent days, however showers running along any marked CZ may tend to train over similar areas, resulting in locally large rainfall totals. A few showers/thunderstorms may also develop in parts of Scotland during the afternoon and early evening hours as well.

For England and Wales, while diurnal heating will lead to increasing instability, forecast profiles reveal substantial subsidence aloft and mid-level capping. It is still plausible a few heavy showers may develop, especially from north Wales and across northern England where a tongue of higher surface dewpoints may exist, although a few odd showers may be possible elsewhere - perhaps also from south Wales and across the Midlands to Lincolnshire. One or two cells may produce a few lightning strikes, but the risk overall is higher in Ireland. If any convection is able to punch higher than the mid-level capping then it may benefit from substantially stronger directional shear given the presence of a jet streak aloft.

 

While showers/storms will tend to decay during the mid-late evening hours, attention then turns to northern France as a shortwave rounding the base of the main upper trough to the west of Biscay engages with the western flank of a relatively high Theta-W airmass over France. The net result is a developing area of showery rain with embedded elevated thunderstorms over the Bay of Biscay during the afternoon hours, moving across the Brest peninsular through the evening hours, this then likely to grow upscale into an area of heavy rainfall across the English Channel and then moving into SW/Cen S England overnight. Exactly how much lightning activity occurs with this feature is uncertain, but there may still be pockets of activity embedded within the broader precipitation shield (perhaps most likely on the eastern flank of precipitation with unimpeded inflow). Additional, more localised elevated showers/thunderstorms will be possible further east along the south coast. The main threat will be the risk of locally high rainfall totals in some southern coastal counties of England, and perhaps also the Channel Islands.

[ChannelThunder]

^ Looks like an episode of 'thundery rain' tonight then? A term you seem to hear less and less these days. 

Model guidance is still all over the place for this, with a range of over 100 miles between certain models on who gets the heaviest rain. Dan's forecast lines up with the UKV's guidance. 

[TwisterGirl81]

Tonight could possible be the first time in 5 weeks we finally get some heavy rain!  We've only had 6.4mm in all that time, thunderstorms would be a bonus but I will take torrential rain for nature, gardens and to refill our water butts.  

[CoventryWeather]

There's been a few reports of a supercell near Birmingham around 3:30pm yesterday. I have a picture showing a scud or potential funnel looking that way at 3:20pm - attached it here to see what people think. Personally thought when I got it it was a scud cloud but discuss yourself. Picture was taken from Foleshill, Coventry looking directly west. 

[Ben Sainsbury]

1 hour ago, CoventryWeather said:

There's been a few reports of a supercell near Birmingham around 3:30pm yesterday. I have a picture showing a scud or potential funnel looking that way at 3:20pm - attached it here to see what people think. Personally thought when I got it it was a scud cloud but discuss yourself. Picture was taken from Foleshill, Coventry looking directly west. 

Having a look at both the image and radar, I'm not really seeing much, if anything, to support a supercell unfortunately. I'd be inclined to go with scud to be honest, as it doesn't seem to resemble a wall-cloud and there doesn't appear to be any obvious rotation.

[Daniel_c150311]

Quiet unstable over here near cardiff

[Coops241180]

Interesting skies to my NW 

[Flash bang flash bang etc]

Looks like the CS is in the firing line for some weather tonight

[alexisj9]

4 hours ago, CoventryWeather said:

There's been a few reports of a supercell near Birmingham around 3:30pm yesterday. I have a picture showing a scud or potential funnel looking that way at 3:20pm - attached it here to see what people think. Personally thought when I got it it was a scud cloud but discuss yourself. Picture was taken from Foleshill, Coventry looking directly west. 

Would be nice to see that from another angle, sort of look like it might be inflow, another angle could confirm that or show that it could be something else.

[Metwatch]

Friend of mine sent this. (@nvangelder03 on twitter who chased with the @thunderyisles group)

B&W edit of a shelf cloud taken around Grantham, Lincolnshire at 17:30 yesterday.

Edited June 19, 2023 by Metwatch

[Aiden2012]

Some good skies about today

[Windblade]

On 16/06/2023 at 14:22, Harry said:

I think there's a great many reasons for optimism to be honest.

Current modelling shows some very moist, humid and unstable air wafting up from the south through Saturday night and more especially through Sunday. Pressure will be falling as a secondary low forms somewhere between the Iberian peninsula and the Bay of Biscay and sweeps up from the south through Sunday evening, bring with it (based on the FAX chart) a number of troughs, as less moist air tries to punch in from the SW.

There is the potential for more than one round of thunderstorms and downpours, as a number of models are suggesting at the moment. I'm seeing signals that there could be thunderstorms/downpours on the leading edge of the humid surge, as it crosses into southern England through the early hours of Sunday, then again later as the drier air begins to sweep the humid air away into the N Sea later in the afternoon and evening. 

As we all should know by now, these are incredibly difficult events to forecast as sometimes the air is so unstable, a cow parping at an awkward angle on the edge of the North Downs could cause storms to initiate. Similarly and by far the worst case scenario, is the models have been wrongly modelling the Low (and more especially the development of the secondary low) and it tracks further east than anticipated.

As it currently stands, this is in my opinion by far Kent/Sussex's best chance for storms this year, with the potential for further heavy and thundery downpours into early next week.

 

Your optimism paid off Harry.  Sunday morning about 1.30am I could hear distant thunder and had a little bit of light rain for about 20 mins. Then at 4.15am we had a little storm and some more lovely rain.  Wasn't a particularly active storm but a storm nonetheless. 

 

19 minutes ago, Metwatch said:

Friend of mine sent this. (@nvangelder03 on twitter who chased with the @thunderyisles group)

B&W edit of a shelf cloud taken around Grantham, Lincolnshire at 17:30 yesterday.

Oh my. Looks like a typical Usa style supercell!

Edited June 19, 2023 by Windblade