Convective/Storm Discussion Thread - 19th May 2018 onwards

[matt111]

Quite dark clouds overhead, nothing happening at the moment although looking at the radar a few showers have appeared further east. Feels humid now as well. 

Edited May 23, 2018 by matt111

[Lauren]

I'll be surprised to see anything tonight tbh.

[Derecho]

 This is what we want to keep our eyes on :)

[Allseasons-Si]

You can see the cells exploding over the Belgium/Dutch borders on here

new cell developed north of Antwerp.

https://en.sat24.com/en/nl/visual

 

good look to those in the south later

Edited May 23, 2018 by Allseasons-si

[Flash bang flash bang etc]

Think this current murk over Sussex would have been quite sparky if the temps were higher.

[Ben Sainsbury]

8 minutes ago, Lauren said:

I'll be surprised to see anything tonight tbh.

I'd actually second this, for some reason I don't have much confidence in the risk of storms tonight, I don't see much potential though likely to be proved wrong!

Then again ConvectiveWeather's forecasts have been very impressive, and brings me a lot of confidence for tonight on the flip side.

[Allseasons-Si]

Mmmm!!!

http://www.estofex.org/

http://www.convectiveweather.co.uk/forecast.php?date=2018-05-23

Day 1 Convective Outlook: Wed 23 May 2018

Day 1 Convective Outlook

VALID 06:00 UTC Wed 23 May 2018 - 05:59 UTC Thu 24 May 201

ISSUED 21:10 UTC Tue 22 May 2018

ISSUED BY: Dan

... WEDNESDAY DAYTIME ...

Very little lightning activity is expected during most of daylight hours, though elements of elevated convection / mid-level instability will advect westwards across East Anglia and SE England at times, bringing occasional showers from high cloud bases here and hence a low (non-zero) risk of lightning. Much of any precipitation will tend to evaporate before reaching the ground.

If enough of a sea breeze / orographic forcing can develop, one or two isolated heavy showers may be possible during the second half of the afternoon over southern coastal counties of England, steering winds then pushing them offshore to the English Channel - however, this is likely quite a low risk, with sea breezes struggling to develop due to a strong offshore gradient wind.

 

... WEDNESDAY NIGHT ...

Advection of warm, moist low-level air from France into SE England during the evening and night hours, combined with subtle cooling / forcing aloft, should gradually increase mid-level instability and hence coverage of elevated convection - initially over SE England, then expanding west or northwestwards through the early hours of Thursday.

 

The exact timing / overlap is crucial in determining how quickly this destabilisation takes place, and therefore how widespread thunderstorm activity may be during this forecast period (and also the exact areas that may be affected). In general, elevated thunderstorms are more likely to develop / be more widespread later in the night - so maybe fairly isolated / well-scattered over SE England, but perhaps a little more numerous further west over central southern England etc.

 

A SLGT has been issued where the best multi-model overlap exists, though it should be noted this may need adjusting / expanding northwards (as per ECMWF) or southwards (as per EURO4) depending on trends during Wednesday. One main precluding factor could be rather weak shear, which may result in messy convection where an individual thunderstorm cell may not last a particularly long period of time. 

 

Edited May 23, 2018 by Allseasons-si

[Chris.R]

  A bit worried to see potential for NW england being slightly downgraded with each run for this weekend. Hope I’m imagining it. 

[Allseasons-Si]

6 minutes ago, Chris.R said:

  A bit worried to see potential for NW england being slightly downgraded with each run for this weekend. Hope I’m imagining it. 

I was hoping that Friday would upgrade too but lets see what happens,i am willing to travel if not too far away over the bank Holiday.

[Flash bang flash bang etc]

15 minutes ago, Ben Sainsbury said:

I'd actually second this, for some reason I don't have much confidence in the risk of storms tonight, I don't see much potential though likely to be proved wrong!

Then again ConvectiveWeather's forecasts have been very impressive, and brings me a lot of confidence for tonight on the flip side.

I’m figuring that as it’s all based on advected heat and forcing there’s been little to scupper the chances during daylight hours.

Also France is doing a good job of generating storms at the moment so i’m feeling quite positive about our overnight chances.

A couple of small cells will suffice but anything more is welcome too

[Windblade]

Lets see what happens tonight. Might leave the window ajar so any storm activity (hopefully) wakes me up. Then again, I was peacefully sleeping through the 80's hurricane til I was rudely woken up by my sister so I'm not sure if a bit of thunder would be enough to get me up!

[East_England_Stormchaser91]

One thing I’ve noticed over the years is that Belgium seems to brew storms like they do Stella! That place is rife for them. 

[Flash bang flash bang etc]

Imagine the far east of Kent may be able to see the heads of those continental storms by now. Skies clearing here near Lewes - which is really good

[A.J]

I'm surprised to see a couple of pessamistic posts in here re. tonight (or is it reverse psychology?)...Dan & Nick wouldn't put out storm forecasts if they didn't think potential was there.......to me it's pretty standard stuff with WAA in the mid levels lifted over cooler lower air mass.....it's just coming from a different direction from the usual due south.........all to play for in my book 

[Thunderstruck]

The real question is can the Belgian and French storms make it across the water? They’ve struggled the past few days...

[Flash bang flash bang etc]

Just now, Thunderstruck said:

The real question is can the Belgian and French storms make it across the water? They’ve struggled the past few days...

If someone empties a few pints of Stella into the sea we might be in with a shout

[A.J]

Just now, Thunderstruck said:

The real question is can the Belgian and French storms make it across the water? They’ve struggled the past few days...

if they're surface based relying on insolation then yes they would struggle, but overnight storms (if they do occur) will be elevated thus based on mid level instability which is there and increasing during the forecast period 

[Stormhog]

Just been a strike off of Dunkirk, unless it's anomalous of course.

[matty40s]

9 minutes ago, East_England_Stormchaser91 said:

One thing I’ve noticed over the years is that Belgium seems to brew storms like they do Stella! That place is rife for them. 

I have yet to see a bubbly storm with an odour of urine.

[Derecho]

Skies have got a stormy look to them here in Southampton but no thunder or lightning.

[matty40s]

2 minutes ago, Stormhog said:

Just been a strike off of Dunkirk, unless it's anomalous of course.

French farmers

[Windblade]

Just now, ajpoolshark said:

I'm surprised to see a couple of pessamistic posts in here re. tonight (or is it reverse psychology?)...Dan & Nick wouldn't put out storm forecasts if they didn't think potential was there.......to me it's pretty standard stuff with WAA in the mid levels lifted over cooler lower air mass.....it's just coming from a different direction from the usual due south.........all to play for in my book 

I think some people are just tired of the contiuous disappointment our hobby can often bring (I've gone through a bout of this recently, having missed out by a whisker on what have been described by many as some of the best storms for years). I don't think anyone has any disrespect for the forecasts/ers, just tempering their expectations while hoping for more, that's all.

[Stormhog]

3 minutes ago, matty40s said:

French farmers

[Lauren]

4 minutes ago, Windblade said:

I think some people are just tired of the contiuous disappointment our hobby can often bring (I've gone through a bout of this recently, having missed out by a whisker on what have been described by many as some of the best storms for years). I don't think anyone has any disrespect for the forecasts/ers, just tempering their expectations while hoping for more, that's all.

Exactly it for me. Have utmost respect for Forecasters, just been burnt too many times is all! 

[Stormhog]

2 minutes ago, Lauren said:

Exactly it for me. Have utmost respect for Forecasters, just been burnt too many times is all! 

I moved to E Sussex specifically for the continental storms, entering the 5th Summer here and I haven't been let down yet, been spectacular.