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Storms and Convective Discussion - 20th April 2019 onwards


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Posted
  • Location: Godalming
  • Weather Preferences: Plumes and streamers
  • Location: Godalming

Apologies if this has already been posted but Paul Blight has upgraded his forecast (and it looks like Sussex is the sweet spot):

 

Convective Outlook - Monday 24th June 2019 
Update 
Issued 10:00 Monday 24th June 2019 



Period 17:00 Monday 24th June until 10:00 Tuesday 24th June 2019 

Changes in Forecast 

UPGRADE this outlook to a VERY HIGH RISK across the South East of England for Organisation of storms which develop over Northern France this evening and move across the Channel. Multicells or Supercells are possible with attendant risk of SEVERE Weather which is now upgraded to 85% . Very High Risk of C/G Lightning (over 50,000 strikes likely) Gusts to over 50knts, Torrential Rainfall Rates likely of over 150mm/h possible. Supercell Thunderstorms are probable especially across Sussex, and northwards towards London. 50-60mm possible in a zone across the purple area.  

RISK AREAS 

See Updated Graphic 

Detail 

Longwave trough within overall upper air cyclonic circulation remains anchored to the SW of the UK, Moderate to strong SW Flow on the eastern side of the trough is interacting with an extremely warm plume of air over Europe, minor shortwaves / filaments of vorticity are rounding the trough axis and moving NNE across Spain, Biscay and into the British Isles. Later today a more significant trough will overrun some very high >20C air at 850mb and 
surface storms wil develop over North Central France. The airmass was well sampled by the 00Z Bordeaux Ascent which shows an elevated mixed layer above a surface inversion. Extrapolating this airmass NNE to lie over the area south of Cherbourg by this afternoon and modifying it to a Surface Temp of 32-33C, removes the surface inversion and allows the growth of surface based storms which will become routed to the 800-900mb level. These storms will then be able to tap into very favourable and possibly even more favourable than the modified sounding shows. The Modified ascent for Bordeaux shows over 2,164 j/kg of MUCAPE with the storm having the ability to grow to 42,000 ft or Tops to -50/-55C . The storms initiate in an area of surface confluence over North Central France with the rising air then able to grow into very large thunderstorms. These multicells have the potential to organise into a Organised convective system routed to the 850mb flow where ample moisture and energy will be available to steer the storm complex across the English Channel and new cells development occurring to the South and SE of the main cells as they move NE. Supercell development is possible across the Sussex area and up into Surrey and West Kent and across London. Westward limit is uncertain at this stage. Bmth/IOW seems to be a good place marker on the western edge and Kent coast on the SE Edge. The storms moving NE during the late evening and through the night across the SE. Frequent Cloud to Ground Lightning - Given such a development as i expect - we can see upwards of 50,000 strikes possible most of these over the SE of the UK. Issues or major issues to the Power Grid may result, Delays to travel highly likely with Heathrow / Gatwick and Stansted being directly in the firing line.  
The Road Network also likely to be affected given the very high rainfall rate potential.  
Storm motion will be to the NE with a 210-220 degree Storm Motion Vector and wind surpporting the movement to the NE. Once over the North Sea tomorrow morning the storms will lose the massive warm ingestion of air and they will weaken over the North Sea.  
60-70mm of rain possible in a few places. 20-30mm in places elsewhere.  

Fig 1 - Updated Risk Box 
Fig 2 - Unmodified Ascent for Bordeaux 
Fig 3 - Modifield Ascent for Bordeaux 
Fig 4 - Afternoon Surface Temps across N France 
Fig 5 - 850mb WPBT air across N France and Corridor towards the NE.

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Posted
  • Location: Morecambe
  • Location: Morecambe

Got to say looking at the situation, things just feel so flat, i mean look at the cloud images, all im seeing is a cold front with normal looking cloud heights heading northwards. 

And as weather history says, the infamous thundery rain term is now being more used. 

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Posted
  • Location: Emsworth, Hampshire
  • Location: Emsworth, Hampshire

As of 11am radar, both the ARPEGE and AROME models are spot on with rainfall distribution across the English Channel and even localised convection over Manchester and Dublin areas, for example.

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Posted
  • Location: South East UK, Reigate
  • Weather Preferences: Wake me up when the storms arrive
  • Location: South East UK, Reigate

In the tradition of naming storms (one the Met Office is keen on), since this is a system moving out of France, full of hot air and moisture...

Should we call it "Storm Macron?"  In honour of our neighbour's President?

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Posted
  • Location: Whaley Bridge - Peak District
  • Location: Whaley Bridge - Peak District

Latest MetOffice forecast moving the potential MCS west more across towards the Midlands, although the SE still seeing the worst of the conditions.

 

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Posted
  • Location: Ludlow, Shropshire
  • Weather Preferences: thunder
  • Location: Ludlow, Shropshire
14 minutes ago, SNOW_JOKE said:

Latest MetOffice forecast moving the potential MCS west more across towards the Midlands, although the SE still seeing the worst of the conditions.

 

Met O matching the netwx-SR model  -  Birmingham,  down to Oxford area ,  IOW.

nmmuk3hrprecip.jpg

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Posted
  • Location: Highworth (122m ASL)
  • Weather Preferences: Snow and a cracking thunderstorm
  • Location: Highworth (122m ASL)
14 minutes ago, SNOW_JOKE said:

Latest MetOffice forecast moving the potential MCS west more across towards the Midlands, although the SE still seeing the worst of the conditions.

 

Think I might grab a wee power-nap in the late-afternoon, looks to be a long night.

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Posted
  • Location: South East UK, Reigate
  • Weather Preferences: Wake me up when the storms arrive
  • Location: South East UK, Reigate

Ian Hislop? That's a bit...out of context!  Thanks for the charts.

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Posted
  • Location: NE Hants/Surrey border
  • Weather Preferences: Cold, Snow, Fog, Frost, Storms and Rain if it rains like it means it.
  • Location: NE Hants/Surrey border

I am sure there were some earlier posts explaining which direction would be best to view the storms from to avoid view being more hindered by rain/cloud. Can anyone explain this again please - I can't find the posts.

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Posted
  • Location: Garforth, Leeds 86m asl
  • Weather Preferences: Heat, Snow, Thunder
  • Location: Garforth, Leeds 86m asl

Just heard 2 rumbles of thunder from the showers that have appeared from nowhere in the past hour! Slate grey skies still as has been all morning, and just started raining. (east Leeds) 

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Posted
  • Location: Norwich, Norfolk, UK
  • Weather Preferences: Anything interesting - mostly storms or snow
  • Location: Norwich, Norfolk, UK

I'm in Norwich and there's been ACCAS about all day.

Most plumes seem to drag the storms either up the east coast, so I'm too far west, or up the Midlands and the wash, then I'm too far east. Or they don't make it this far north at all. Been a while since I've taken a direct hit from a decent storm, rather than getting the dreggs from the peripheries.

Here's hoping.

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Posted
  • Location: Belper, Derbyshire
  • Weather Preferences: Thunderstorms
  • Location: Belper, Derbyshire
17 minutes ago, Mizzle said:

I am sure there were some earlier posts explaining which direction would be best to view the storms from to avoid view being more hindered by rain/cloud. Can anyone explain this again please - I can't find the posts.

You'd ideally want to be to the east of the storm system.

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Posted
  • Location: Sunderland
  • Weather Preferences: Hot Summer, Snowy winter and thunderstorms all year round!
  • Location: Sunderland
59 minutes ago, Flash bang flash bang etc said:

I am calling this storm Thunderstorm Ian Hislop

Here are the missing charts courtesy of PJB @ UKWW

 

C904383F-5BC8-4E5A-968D-A5E3279FD57D.thumb.png.be643c985b1c9e59d2028c4ea52cd8b9.png

0CCDCF0C-96CA-479A-A263-3F7921529D1C.png.f6bec1925fbddc7bcff60b4ee1ab80ab.png

 

#thunderstormianhislop

oh wonderful, bloody Sarf East again.......what does it take to get a decent storm in my area....used to have lots now diddly squat since april last year.....overall despite looking great up to about 2 days ago, everything has it's usual easterly shunt......that's my moan for the day

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Posted
  • Location: Ludlow, Shropshire
  • Weather Preferences: thunder
  • Location: Ludlow, Shropshire
1 minute ago, A.J said:

oh wonderful, bloody Sarf East again.......what does it take to get a decent storm in my area....used to have lots now diddly squat since april last year.....overall despite looking great up to about 2 days ago, everything has it's usual easterly shunt......that's my moan for the day

Hmm.. I don't think it will be  - If I had to put money on it I would say Bristol has a higher chance of seeing lightning overnight than London.  That's a huge punt I know but will see.

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Posted
  • Location: Andover, Hampshire
  • Location: Andover, Hampshire

Huge upgrade for the SE from PJB on UKWW.

probable multicells and supercells. You lot get your cameras out and don’t let me down!

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Posted
  • Location: Dorset
  • Weather Preferences: warehamwx.co.uk
  • Location: Dorset
2 minutes ago, StormChaseUK said:

Hmm.. I don't think it will be  - If I had to put money on it I would say Bristol has a higher chance of seeing lightning overnight than London.  That's a huge punt I know but will see.

I don't know what you're using to come up with that idea?

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Posted
  • Location: Sunderland
  • Weather Preferences: Hot Summer, Snowy winter and thunderstorms all year round!
  • Location: Sunderland
2 minutes ago, StormChaseUK said:

Hmm.. I don't think it will be  - If I had to put money on it I would say Bristol has a higher chance of seeing lightning overnight than London.  That's a huge punt I know but will see.

very doubtful.....a lack of instability, energy and bouyancy for areas rest of London according to hi-res (nmm) modelling)....3 key ingredients for any type of thunderstorm........hope it's modelling it all wrong and instability is further west, but  I doubt it

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Posted
  • Location: Leicester
  • Location: Leicester

Can’t see any action, if any, for the Midlands until tonight. 

Even then it could just be your bog standard rain event.

BBC have even amended their text forecast to just isolated showers for this afternoon and evening. 

Edited by Josh Rubio
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Posted
  • Location: Rushden. Northamptonshire
  • Weather Preferences: Thunderstorms
  • Location: Rushden. Northamptonshire

Do I dare say to myself that my location looks within a fair chance of some of the heavy most intense parts of the storm tonight. As long as there is not huge shifts eastwards throughout the day of course.

On a serious note, do I not water my plants due to foretasted rain knowing that if I water them it will obviously rain? Rushesssss to the watering can.........

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Posted
  • Location: Livingston (ish)
  • Location: Livingston (ish)

Well it seems that the bit of Scotland removed from the Met office warning for thunder is currently experiencing... thunder... who'da thunk it? It's still between 10 and 20 miles from me, but I'm hearing the odd rumble. Keeping an eye on lightning maps and rain radar.

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Posted
  • Location: Sawbridgeworth, Hertfordshire
  • Location: Sawbridgeworth, Hertfordshire
4 hours ago, Hammer said:

METO predictive rainfall had storms pretty much edging in to SE then EA and up NE earlier when I looked for 1am tomorrow onwards, but after just looking again they now have storms running up through central Southern England, Midlands.

So quoting my earlier post where METO had shifted west, METO predictive rainfall on app now shifted things back further East again. So interesting evening ahead. 

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Posted
  • Location: Hatfield Peverel near Chelmsford Essex
  • Location: Hatfield Peverel near Chelmsford Essex

Looks like I'm in a good spot, storms went just to the east last time and knowing my luck they will go just west.

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Posted
  • Location: Boldon, South Tyneside (Tyne & Wear) 271ft ASL
  • Weather Preferences: Severe Thunderstorms, Heat (Summer) & Snow in Winter
  • Location: Boldon, South Tyneside (Tyne & Wear) 271ft ASL

Some mini potent showers headed into the North East but no strikes shown for a while. Bit gutted so far as was hoping to catch something but we live in hope!

 

Edit: started back up again now.

Edited by P-M
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