Storms and Convective discussion - 16th June 2021 onwards

[Harry]

3 minutes ago, poseidon said:

Just had quite a severe storm here. Plenty of thunder/lightning and crazy rainfall + slow moving with it.  I've rarely seen rain that heavy in the UK. Looks to have intensified even more as it moved South.

Seems to be drifting slowly this way but will probably track slightly to my west. If it can maintain strength I might get some distant flashes and rumbles

[matty40s]

The bury st Edmonds and Harlow storms, and then the Harlow on it's own....can hear rumbling from here.

[matty40s]

Bury stE one getting bigger.

[poseidon]

2 minutes ago, Harry said:

Seems to be drifting slowly this way but will probably track slightly to my west. If it can maintain strength I might get some distant flashes and rumbles

Does look to be losing rainfall intensity, from the radar. Most of the lightning didn't register on Blitzortung.

[ChannelThunder]

1 hour ago, Mapantz said:

Yep. I was just looking at the accumulation map

I'm still chuckling over the fact that all that rain fell before the warning was active

 

 

Which app is it that's showing you the accumulation info? I have the Windy one but it doesn't seem to be featured.

[Sparkiee storm]

1 hour ago, Flash bang flash bang etc said:

Yeah was watching this curious thing. Isn’t it supposed to spin the other way? I can’t remember

 

looks to be dissipating, but I reckon it spawned a funnel or two

Im not sure but the CZ was created by an Easterly breeze running into a Northerly i think, so if im thinking correctly it would create it this way lol.

Edited July 12, 2021 by Sparkiee storm

[Mapantz]

1 minute ago, Lance M said:

Which app is it that's showing you the accumulation info? I have the Windy one but it doesn't seem to be featured.

It's the NetWeather V8 radar web app, Lance.

[Daniel*]

I was in Westminster at time and Lord above around not long after 4pm heavens opened, some of heaviest rain I’ve ever seen biblical roads turned to rivers, also thunder and lightning so quite the event, a few miles east at home we had 1mm in Putney they had over 70mm! One of craziest narrowest west to east splits I’ve ever seen. 

 

[Sprites]

14 hours ago, matty40s said:

Bury stE one getting bigger.

I didn't here thunder yesterday nr BSE, or see any sferics on the maps. There was a heavy shower a few miles to the south around 6pm. Only 1mm here, very localised. 

Nice photo though.

Edited July 13, 2021 by Sprites

[Sprites]

Question 

Is the rainfall accumulations option on radar,or app, only for Netweather extra?.

Edited July 13, 2021 by Sprites

[ChannelThunder]

3 hours ago, Sprites said:

Question 

Is the rainfall accumulations option on radar,or app, only for Netweather extra?.

I had a look following Mapantz's reply to me yesterday, and it's one of the features you can unlock with Radar Extra.

Attention now turns to next week, storm-wise. Some models break down the upcoming warm spell with a Biscay low. Very early days on this one, so just one to watch over the next couple of days to see if the idea sticks.

Edited July 13, 2021 by Lance M

[A Face like Thunder]

Strangely perhaps in view of the above posts, the wettest place in Britain yesterday is shown as Topcliffe in N Yorkshire with 45.4mm (Times). This is close to where I was travelling yesterday and I can confirm that heavy showers were the order of the day, so maybe this rainfall came as a result of one or more of these showers. 

[Cakie]

1 minute ago, A Face like Thunder said:

Strangely perhaps in view of the above posts, the wettest place in Britain yesterday is shown as Topcliffe in N Yorkshire with 45.4mm (Times). This is close to where I was travelling yesterday and I can confirm that heavy showers were the order of the day, so maybe this rainfall came as a result of one or more of these showers. 

I can concur, we were travelling through Thirsk yesterday and the flooding was terrible. Sutton Bank was equally bad but it was obviously just rolling down the hill. 

[Sprites]

14 hours ago, Cakie said:

I can concur, we were travelling through Thirsk yesterday and the flooding was terrible. Sutton Bank was equally bad but it was obviously just rolling down the hill. 

OT Is Sutton Bank still the narrow curving steep road as I remember, with the viewpoint at the top. Or has the road layout been changed ?

[Derbyshire_snow]

1 hour ago, Sprites said:

OT Is Sutton Bank still the narrow curving steep road as I remember, with the viewpoint at the top. Or has the road layout been changed ?

Yes it is a very steep  road and not for the faint hearted still.

[TJS1998Tom]

Looks like some hot weather coming up, wonder if we'll see another chance of storms in the coming week or so

[Harry]

27 minutes ago, TJS1998Tom said:

Looks like some hot weather coming up, wonder if we'll see another chance of storms in the coming week or so

Nothing notable at the moment @TJS1998Tom. Some potential indicated for home grown storms in places over the weekend, but nothing very widespread or plume like. Hints on GFS for a plume late next week but that’s far too far out to be of any interest in my view.

[BrickFielder]

Tricky to say whether storms might be on the cards today and generally speaking anticyclonic environments are not conducive to storm development due to dry sinking upper air.

The other problem with anticyclonic conditions is that although there is instability there is no trigger for storm initiation. Low level wind convergence, orographic lift (hills and mountains) become your only triggers. Today modeling is not really in agreement about where low level wind convergence is.

There is no agreement on whether convection occurs at all.

 

Looking at forecast Skewt's I can see instability with moister air coming aloft from the West. Comparing to soundings and current conditions I can see a tendency to underestimate dewpoints (17C already in some places) but also that humidity is very shallow (Nottingham sounding from last night) and with a bit of a warm nose at 500hpa.

Pulling it altogether is a bit tricky and convection is likely to be isolated and I think late afternoon when moisture comes in aloft would be the likely time for storms. Lightning wizard charts show some risks of supercells and spouts in places so an isolated storm could be severe.

My gut feeling is there will be no storms, but I am watching an upper level disturbance on the Eumetsat images (satellite RGB images) currently across northern England which is forecast to slip southwards over the Midlands later to see if it over runs a low level convergence zone (Chance of a surprise storm). Not sure what other forecaster's  think?

 

[Sparkiee storm]

Brickfielder above & Convective Weather have similar forecasts on today's small potential.

http://www.convectiveweather.co.uk/forecast.php?date=2021-07-18 

Day 1 Convective Outlook: Sun 18 Jul 2021   

        

Day 1 Convective Outlook

VALID 06:00 UTC Sun 18 Jul 2021 - 05:59 UTC Mon 19 Jul 2021

ISSUED 05:16 UTC Sun 18 Jul 2021

ISSUED BY: Dan

Upper ridging dominates across the UK/Ireland through Sunday, with a gradual weakening through this forecast period. Strong insolation and resultant diurnal heating will result in deep mixing of the low-levels, and while forecast profiles suggest potential for several hundred J/kg SBCAPE it seems likely that what convective cloud can develop will either be restricted in height by warm noses aloft, or struggle to maintain itself due to the dry mid/upper troposphere. Consequently, despite perhaps numerous attempts at fair-weather convective cloud attempting to gain some height, it may fail to produce many showers (at least for any length of time per individual cell).

The main focus where convection may be a little more sustained is along marked convergence zones, such as in central Ireland and through Yorkshire/Lincolnshire, or aided by orographic forcing such as in Wales. The overall lightning risk is very low, but perhaps particular attention is given to central Ireland and the S + W Midlands during the evening hours where some subtle forcing aloft approaching from the west may phase with pre-existing convergence zones to briefly (for a couple of hours) enable convection to grow tall enough to produce an isolated heavy shower / thunderstorm. If this does occur, some local surface water issues could result.

 

During the early hours of Monday, there could be an uptick in elevated convection across East Anglia - although the risk of lightning is considered rather low.

[Turquoise]

Nothing to see here folks, just enjoy the glorious hot sunshine

[The PIT]

Probably explains why there's more cloud around today.

[Chris Lea-Alex]

2 hours ago, BrickFielder said:

....

 

My gut feeling is there will be no storms...

 

I'm certainly not a forecaster, but this is my gut too.  I wasn't planning on even going on the convective weather website until Thursday.

Even when there are triggers, we don't do well for storms

[WeatherWatchmanG]

Confidence in storms must be high keeps updating and showing both forecasted and rain map too on the met office very localized and heavy though so its going to be very spread out.

[Dangerous55019]

Hello everyone.
Well I certainly wasn’t expecting to see anything exciting happening today, so I’ve spent most of the day inside sheltering from the heat. 

So imagine my surprise to see this lot bubbling up to my south!!

Sadly I don’t think it’ll go bang, (although I’d love it to. ?⛈) but it’s still nice to see the potential.

[samadamsuk]

I'd be surprised if its not raining east of Cirencester- this is looking roughly towards Reading.