Storms and Convective discussion - 16th June 2021 onwards

[Chris Lea-Alex]

4 minutes ago, Frosty hollows said:

Keeping my eye on this to my SE. Developed pretty rapidly 

I'm facing straight east from the blue dot. Thinking of heading straight home to be honest!

Edited June 27, 2021 by Chris Lea-Alex

[Frosty hollows]

9 minutes ago, Chris Lea-Alex said:

I'm facing straight east from the blue dot. Thinking of heading straight home to be honest!

That band of heavy rain is going to my south, but there are lots of little cells popping up to my north too. I'm stuck in the dry bit!

[Windblade]

3 hours ago, Azuremoon2 said:

oh look the south east hogging all the storms again......nothing new there then.

I hope you're joking. Storm activity has been an absolute joke round here for the past five years, with every single major event either missing us completely or not even starting. Bexley has to be the storm deadzone of the uk.

Edited June 27, 2021 by Windblade

[Harry]

1 minute ago, Windblade said:

I hope you're joking. Storm activity has been an absolute joke round here for the past five years, with every single major event either missing us or not even starting. Bexley has to be the storm deadzone of the uk.

Yeah hasn’t been great has it @Windblade. Almost every storm (and there were quite a few) slid past last year. Had a cracking storm here in mid May but nothing much else this year so far

[Sparkiee storm]

What's this Vortex/Swirl within the frontal band in the South East? Heard of MCV's but I don't think I've ever seen one within a front.

[Peachy]

I'm just south of Oxford at the moment,  no storm yet but the sky above is gearing up for something 

 

[viking_smb]

3 minutes ago, Sparkiee storm said:

What's this Vortex/Swirl within the frontal band in the South East? Heard of MCV's but I don't think I've ever seen one within a front.

i noticed that on radar as well 

[Chris Lea-Alex]

4 minutes ago, Peachy said:

I'm just south of Oxford at the moment,  no storm yet but the sky above is gearing up for something 

 

Those clouds are fit.

Below: I'm gonna pretend this wasn't a wasted journey

Edited June 27, 2021 by Chris Lea-Alex

[Frosty hollows]

5 minutes ago, Peachy said:

I'm just south of Oxford at the moment,  no storm yet but the sky above is gearing up for something 

 

I'm under a punchy cell right now but sky is just grey here. Lovely capture!

[Frosty hollows]

12 minutes ago, Chris Lea-Alex said:

Those clouds are fit.

Below: I'm gonna pretend this wasn't a wasted journey

You're in the right place if anything was to happen. That cell that left me has pepped up!

[Allseasons-Si]

Is there a Storms and Convective moans thread,....Jeez it's like the MOD thread in winter in here sometimes ha ha

there is plenty of time this summer and looking at the longwave pattern setting up shop later this week onwards with a low to the west of the BI,there is every chance of another Spanish plume down the line

chins up guys eh

 

[Allseasons-Si]

I would say that this is looking spot on with Dan's forecast.

Edited June 27, 2021 by Allseasons-si

[staplehurst]

5 minutes ago, Allseasons-si said:

I would say that this is looking spot on with Dan's forecast.

Just lacking in thunder - although we've said all along (see post from last night) that because the profiles are so moist this tends to reduce the lightning potential and you just end up with heavy downpours and very little lightning. 

[Chris Lea-Alex]

2 minutes ago, Allseasons-si said:

I would say that this is looking chicken on with Dan's forecast.

I think that today had the potential to be very special indeed.  Had that organised rain been electrified somebody could have enjoyed hours of storms.

[StormLoser]

50 minutes ago, Sparkiee storm said:

What's this Vortex/Swirl within the frontal band in the South East? Heard of MCV's but I don't think I've ever seen one within a front.

That's heading right for me. Might lessen the steady rain and total lack of any electrical activity. I think it's just a trough merging into the north-pushing cold front.

Looks good on the radar!

Looking further, it is compressing stuff as it progresses west...   

Edited June 27, 2021 by StormLoser

[Harry]

On to tomorrow

[Chris Lea-Alex]

6 minutes ago, staplehurst said:

Just lacking in thunder - although we've said all along (see post from last night) that because the profiles are so moist this tends to reduce the lightning potential and you just end up with heavy downpours and very little lightning. 

Is there any kind of discussion / study etc on this because, whenever I've gone driving after a plume 'event' or something, the rain seems to calm down the lightning, or at least keep it in the clouds.  

I don't know my weather, but this is what I've been noticing so far when out in it.  It could be coincidental of course, I have an open mind

 

Edited June 27, 2021 by Chris Lea-Alex

[Mapantz]

3 minutes ago, Harry said:

On to tomorrow

This is about as good as it get's on the UKV:

I'm just astounded at the lack of rainfall here.

[Norfolk Sheep]

22 hours ago, staplehurst said:

Tomorrow exhibits some similarities to 16 August 2020, which produced some extreme rainfall totals in south Norfolk (240mm in 6-8 hours). There is a paper currently being published on the meteorology of this event.

It seems likely a convergence zone may develop in the afternoon somewhere near or just north of the M4 across to Hertfordshire. North of this boundary, a brisk northeasterly wind will, in theory, allow a continuous supply of 'heated' air from East Anglia (where the best potential for cloud breaks is likely by midday and into the afternoon), and this will result in pooling of warm, moist air along this boundary during the afternoon. In @Paul Sherman speak, "spreads" could be 72F/61F over East Anglia.

Winds aloft are fairly unidirectional (mostly from the ESE), and would in theory steer any storm cells to the WNW or NW, while inflow winds near ground level will be perpendicular (from the NE) and of similar speed to the storm motion. This will help restrain cold outflow / gust front from advancing too far away from the parent cell, and in theory aid the development of daughter cells in a similar location, such that *somewhere* could get multiple cells training over the same area. Profiles are very moist, with a substantial amount of the cloud below the freezing level, so these could deliver a LOT of rain over a period of a few hours. BUT this is highly dependent on many factors, namely the convergence zone developing in the first place and sufficient surface heating, both of which could be scuppered if there's too much cloud/rain or it advances too quickly northwards.

We often see in the U.S. how the shape/progress of convergence boundaries can get distorted by rain-cooled air from earlier convection, etc.

The main difference between this event and last August is the magnitude of instability is lower, and the window of potential shorter - so both will mean rain totals will be lower. Either way, currently keeping an eye on the south Midlands / M4 corridor for the risk of some fairly large rainfall totals (various NWP guidance suggests 50-70mm possible, KNMI Harmonie fancies near 100mm on some runs). Perhaps Bucks / Oxfordshire / Berkshire / N Wiltshire / E Glocs most at risk, but need to keep an eye on trends during Sunday to see if this potential still exists. This of course is not including the more widespread heavy rain that will be affecting other parts of Cen S / SW England.

Note: I'm not necessarily promising loads of lightning because profiles will be very moist, but scope for some torrential downpours and flash flooding etc.

Hmm yes, I remember 16th August (never go looking for interesting weather in a Mini!) 

Screen grab of rainfall  - the thing was that it didn't look particularly threatening but the amount of water that fell out of the sky in a short space of time was incredible. I drove Dereham - Shipdam - Bradenham - Saham/Ashill - Watton; Saham and Ashill were literally underwater in about 20 minutes. 

[Supacell]

30 minutes ago, Allseasons-si said:

Is there a Storms and Convective moans thread,....Jeez it's like the MOD thread in winter in here sometimes ha ha

there is plenty of time this summer and looking at the longwave pattern setting up shop later this week onwards with a low to the west of the BI,there is every chance of another Spanish plume down the line

chins up guys eh

 

There actually is, and it would be great if those who want to moan actually used it

 

 

[Harry]

Torrential rain now - final throw of the dice for tonight 

EDIT - Ignore that, the rain is biblical. The rumbling on the roof is insane.

Edited June 27, 2021 by Harry

[NO LONGER POSTING]

17 minutes ago, Harry said:

Torrential rain now - final throw of the dice for tonight 

EDIT - Ignore that, the rain is biblical. The rumbling in the roof is insane.

Yeh quite something when you find yourself under 200-250mm an hour rainfall rates.. the noise it makes to me is magical... my favourite weather this laying in bed hearing it come down..

Quick check out the window and may need the boat tomorrow to go to work but hey.. its tropical alright!

[Harry]

UKV backing right off any notable storm risk across the south tomorrow

[Robbie Garrett]

4 hours ago, Storm_Sikher said:

The storm on Friday night that produced the 'Nado in London, this was taken about an hour later at 9PM looking over Tilbury.

Supercell?

15 minutes ago, Harry said:

UKV backing right off any notable storm risk across the south tomorrow

Yeah right, guess who's due to fly tomorrow to Lydd as part of my IR training. Will be embedded CBs all day long... 

[alexisj9]

3 hours ago, Chris Lea-Alex said:

I'm facing straight east from the blue dot. Thinking of heading straight home to be honest!

Rain done back to fog here.