Storms and Convective discussion - 1st May 2022 onwards

[Ben Sainsbury]

With respect to BrickFielder, I am still interested in tomorrows potential, however we need a number of things to come together for thundery activity to be maximised. 

If cloud tops can reach sufficient heights tomorrow, then cells will have the ability to tap into some relatively strong wind shear, this in-turn will lead to organisation of a few cells with some fairly sporadic lightning and some decent sized hail for a time. For this to happen we need sufficient surface heating tomorrow, to build up that instability and the greater the instability then the higher the cloud tops are likely to reach. 

The amount of surface heating tomorrow will be dependent on the speed that the occluded front clears ESE'wards across England. The quicker the clearance, the more surface heating. For the most part the majority of cells won't be able to reach sufficient heights to tap into the wind shear, but I would imagine a few cells, particularly where we see the greatest instability tomorrow (Cambs, Herts, Beds, Bucks), may become organised for a time.

Edited May 3, 2022 by Ben Sainsbury

[The Tall Weatherman]

For god sake! Tomorrow I am going on holiday to the Peak District and I can’t change that. I better set my webcam up then!

[BrickFielder]

1 hour ago, Ben Sainsbury said:

With respect to BrickFielder, I am still interested in tomorrows potential, however we need a number of things to come together for thundery activity to be maximised. 

Not a bad call Ben and as ever models can chop and change. Forecast SkewTs now suggest about 18C and dewpoints of 10C might be enough. The difference is down to upper air being forecast to be a. touch cooler.

I am not sure the wind shear helps  in the way you suggest. I think it will push tops out ahead of convection southwards which might result in pulse storms along low level wind convergence lines. High level cloud might be  a risk to convection as dewpoints might match temperatures just below the jetstream. I expect charts will change over night so the risk might change and risk in the north east should not be ruled out.

[The Tall Weatherman]

The recent charts are showing some gnarly storms tomorrow and The GFS is giving moderate lapse rates to enhance lightning potential along with Cape reaching 600 or more if temperatures can reach higher than 16 degrees. Sadly I am going on holiday to the Peak District but from what the models say the storms will be heading towards us on the way at 11 o’clock. Anyways the largest threat I would pin down would be dead on central Britain. I would not be surprised if Convective weather issued a High end Slight with Severe tomorrow but let’s just wait and see. 

[Ben Sainsbury]

1 hour ago, BrickFielder said:

Not a bad call Ben and as ever models can chop and change. Forecast SkewTs now suggest about 18C and dewpoints of 10C might be enough. The difference is down to upper air being forecast to be a. touch cooler.

I am not sure the wind shear helps  in the way you suggest. I think it will push tops out ahead of convection southwards which might result in pulse storms along low level wind convergence lines. High level cloud might be  a risk to convection as dewpoints might match temperatures just below the jetstream. I expect charts will change over night so the risk might change and risk in the north east should not be ruled out.

Good spot this! As always minor differences can lead to significant changes in the model output, valuable having your input!

[Eagle Eye]

I'll be in the north of Kent on a class trip tomorrow (ironically geography), maybe a better chance of getting a photo or two, or one on the way back as well than being further south. Finally, interesting weather slightly coinciding with school times where me going to school that day helps me get potentially closer to the storms/showers. I think school brought this weather, always seems to happen on trip days .

[Methuselah]

1 minute ago, Eagle Eye said:

I'll be in the north of Kent on a class trip tomorrow (ironically geography), maybe a better chance of getting a photo or two, or one on the way back as well than being further south. Finally, interesting weather slightly coinciding with school times where me going to school that day helps me get potentially closer to the storms/showers. I think school brought this weather, always seems to happen on trip days .

We had a stonker of a storm in Tunbridge Wells, in late May 1970 (it could have been early June?) EE: it just sat over our school (Huntley's Secondary Modern) for what seemed like hours. Probably nearer to half an hour!

[Eagle Eye]

1 minute ago, Ed Stone said:

We had a stonker of a storm in Tunbridge Wells, in late May 1970 (it could have been early June?) EE: it just sat over our school (Huntley's Secondary Modern) for what seemed like hours. Probably nearer to half an hour!

Reminds me of, I think 2014 in year 2 (I can't remember that far back for exact years but I can remember the picture of the storm well, a massive anvil cloud that rolled in and was an extremely dark blue colour but I don't remember much lightning from it only loud rumbles of thunder).
Then 3 or 4 years later, a highly electrical storm came over and lasted from just after break until early lunch. I remember well, the blue lightning strikes and anvil crawlers that came right above me, closest a daytime storm has come at school time (had to put ear defenders on because I used to be scared, thanks to Jimmy whoever and wherever he is for getting me them as I covered my ears ), noticeable lack of school time storms since I left primary school but an increase in after school storms, plumes also seem to have gone down though.

[The Tall Weatherman]

13 minutes ago, Eagle Eye said:

I'll be in the north of Kent on a class trip tomorrow (ironically geography), maybe a better chance of getting a photo or two, or one on the way back as well than being further south. Finally, interesting weather slightly coinciding with school times where me going to school that day helps me get potentially closer to the storms/showers. I think school brought this weather, always seems to happen on trip days .

I am still questioning if the storms will be as potent near Kent. The storms in Kent based on the UKV runs are showing it would probably arrive around 5:30pm to 6pm which is when the Cape falls apart and the Lapse rates are low. I am annoyingly going to the Peak District tomorrow but I hope I can get a nice photo when the storms start to explode West Midlands/ Yorkshire moving east with possible sporadic lightning based on the models. I am excited to see the convective weather forecast tomorrow.

[Allseasons-Si]

CW forecast just released  

------------------------------------

Day 2 Convective Outlook

VALID 06:00 UTC Wed 04 May 2022 - 05:59 UTC Thu 05 May 2022

ISSUED 19:43 UTC Tue 03 May 2022

ISSUED BY: Dan

A PV anomaly will slide southeastwards across Britain during Wednesday daytime, with heights falling temporarily and cooling in the mid/upper troposphere coinciding with peak diurnal heating. The net result is the potential for much deeper convection than on Tuesday. Fairly extensive cloud during the morning, and areas of showery rain, will gradually break due to convective overturning, with an increasing risk of heavy showers evolving/developing across central and eastern England from around noon and through the afternoon and early evening. Surface temperatures of 15-17C and dewpoints 10-12C will likely yield 400-600 J/kg CAPE in a relatively narrow corridor (spatially) that will shift gradually southeastwards through the afternoon. Forecast profiles reveal skinny CAPE within a modestly sheared environment of 20-30kts as northwesterly flow aloft strengthens from the west on the rear side of the upper trough; a combination of both speed shear, as flow strengthens with height, and also some directional shear with NW-ly winds aloft and backed W or even WSW surface winds.

Some concerns exist over just how cool the mid troposphere can become, with some evidence of a slight warm bulge at 500-550hPa which may inhibit air parcels passing this point (and therefore stunt convective cloud growth and reduce the lightning risk), or at the least lead to slower parcel accelerations. Assuming convection can grow tall enough, then a few cells may become somewhat organised and longer lasting with some sporadic lightning and sub-severe hail - and as such, a low-end SLGT has been issued. But it is plausible many of the showers may be void of much in the way of lightning. Showers/thunderstorms will gradually decay and clear eastwards during the evening hours.

source:-

Convective Weather

WWW.CONVECTIVEWEATHER.CO.UK

---

Forecasting thunderstorms and severe convective weather across the British Isles and Ireland for up to the next 5 days.

i finish work at 2pm tomorrow,...going to get things setup ie:-cam,batteries,tripod etc and maybe travel east of here possibly SE

good luck all,this could be our first thundery/convective day of the year

BTW the 12z gfs is consistent all be it FL at a plume event,...i am praying that this comes off

  

Edited May 3, 2022 by Allseasons-si

[Eagle Eye]

14 minutes ago, The Tall Weatherman said:

I am still questioning if the storms will be as potent near Kent. The storms in Kent based on the UKV runs are showing it would probably arrive around 5:30pm to 6pm which is when the Cape falls apart and the Lapse rates are low. I am annoyingly going to the Peak District tomorrow but I hope I can get a nice photo when the storms start to explode West Midlands/ Yorkshire moving east with possible sporadic lightning based on the models. I am excited to see the convective weather forecast tomorrow.

Just like that the forecast is out and I'll be in the slight risk but I will say that I think most of it'll stay north and east of me.

[Arnie Pie]

41 minutes ago, The Tall Weatherman said:

I am still questioning if the storms will be as potent near Kent. The storms in Kent based on the UKV runs are showing it would probably arrive around 5:30pm to 6pm which is when the Cape falls apart and the Lapse rates are low. I am annoyingly going to the Peak District tomorrow but I hope I can get a nice photo when the storms start to explode West Midlands/ Yorkshire moving east with possible sporadic lightning based on the models. I am excited to see the convective weather forecast tomorrow.

Hopefully I`m your man

Brumcam will be streaming from late morning tomorrow

I witnessed some late afternoon convection today.... and it`s starting to feel a bit muggy around these parts....Unless that's my seasonal anticipation menopause kicking in again

[The Tall Weatherman]

9 hours ago, Arnie Pie said:

Hopefully I`m your man

Brumcam will be streaming from late morning tomorrow

I witnessed some late afternoon convection today.... and it`s starting to feel a bit muggy around these parts....Unless that's my seasonal anticipation menopause kicking in again

I am actually going to be passing Birmingham at 10:30AM late morning going to the Peak District and I do think the storms early in their life near Birmingham might be electrically active for a time around 11AM to 12AM where the conditions seem more favourable. I do think the most potent storms today will be in central Britain where a line of Thunderstorms develops on the UKV run with possible Hailers in front of it at peak heating.

[Nick F]

THUNDERSTORM WATCH - WEDS 4TH MAY 2022

Issued 2022-05-04 08:09:01
Valid: 04/05/2022 0600 - 05/05/2022 0600

Forecast Details

Upper trough will clear east across the UK this morning, cool air in the mid / upper levels in association with the trough's passage will create an unstable atmosphere to surface heating today - particularly across central, S + E England this afternoon / early evening - with peak heating possibly yielding 300-600 j/kg CAPE later afternoon. Despite the trough axis clearing east, a lobe of vorticity on the rear side of the trough and surface occluded front both moving SE will provide more forcing than yesterday - so cumulonimbus clouds will likely grow taller and produce heavier showers with hail and locally thunder. Some localised flooding is possible with heavier showers / storms before they gradually fade through the evening as surface heating wanes. 

Issued by: Nick Finnis

Severe Convective Weather & Storms Forecast - Netweather.tv

WWW.NETWEATHER.TV

 

[BrickFielder]

Instability looks fairly weak (skinny cape) so not a widespread outbreak of severe storms. There is some directional shear through mid levels which might be suggest potential for turning cells (not supercell characteristics because you need a strong updraft/high instability) which may help in cell longevity. Generally low level wind speed shear looks poor although we should expect some convergence zones and gfs/lightning wizard suggest some stronger low level winds (Not likely inflow winds as updraft strength is not high). This macro level detail will not show up on a lot of forecasting model data so it is possible low level shear could be locally higher than generally suggested. One limiting factor is that the vorticity lobe expected is not really showing up clearly on Eumetsat satellite imagery yet. Storm forecasting with temperatures below 20C is always a bit tricky at the best of times, so best of watching the Netweather radar and satellite images.

[Harry]

Cloud melting away here now with the sun coming through - hope it stays that way and the cloud doesn’t fill back in.

First interesting day of the year though - good luck all.

[Paul]

A nice way to whet the appetite for a new storm season.

 

[Arnie Pie]

Weak convection atm.....but beginning to increase

Looking good for more Southern areas later on

[Harry]

20 minutes ago, Arnie Pie said:

Weak convection atm.....but beginning to increase

Looking good for more Southern areas later on

Got a band of light rain here at the moment (after earlier optimism when the sun came out).

Definitely the most humid feeling day of the 'season' so far, so definitely more moisture to rise through the atmosphere as the upper levels cool this afternoon.

[Frosty hollows]

Feeling very oppressive here after some lovely lunchtime sunshine.  Showers popping up to my NW...could be an interesting afternoon 

[Andy Bown]

Oh look, first strike in Lincolnshire, UK storm capital !

[matty40s]

First clap of thunder between Daventry and Northampton, bit of a wet fart though.

[biddie]

Kicking off further north Midlands upwards all moving east. Band of showers in a line . Herts beds soon but looks mainly rain there. Some very heavy.  Looks like getting more organised further north.

[East_England_Stormchaser91]

After a stratiformed disappointing morning, the sun has burst through, cumulus bubbling up and feeling quite oppressive. Can see the towering CB’s over Lincolnshire! Pretty darn tall with good anvils. 

[Eagle Eye]

 

Someone I know on Discord got this.

A large updraft near here earlier, as far as I could tell some weak rotation possibly in it as well.