Convective / Storm Discussion Thread - 27th Feb onwards

[Harry]

Not a drop of rain here today - full marks to the forecasters for the accuracy of the forecast today.

As for threats of a plume later next week, I'm putting odds at <10%. Models reducing any 'plume' to an increasingly narrow slither of moisture. Looking quite forward to a dry and warm(ish) spell over the next few days. 

[Allseasons-Si]

As Supacell said,monday could be the next opportunity going by the 18z gfs,at this stage the midlands northward

then the end of next week(Thu,Fri) altough ppn is a bit sparse but i wouldn't worry about this at this juncture

meanwhile lets enjoy the warmth and hopefully things spark off later

Edited May 20, 2017 by Allseasons-si

[Allseasons-Si]

Then,at a stretch.....bank holiday monday

here is a closer look

juicy

Edited May 20, 2017 by Allseasons-si

[Chris Lea-Alex]

39 minutes ago, Allseasons-si said:

lol

the storm must have got it's juice from there

Let's fill up right away before there's a strike...

[Harry]

Bank bank bank bank bank bank!!!!

Edited May 21, 2017 by Harry

[East_England_Stormchaser91]

2 hours ago, Harry said:

Bank bank bank bank bank bank!!!!

Pure eye candy! First real taste of some storm porn this year. 

[TJS1998Tom]

12z Still showing a storm risk for next Saturday, on the charts it looks like it's moving North East wards?

[richep]

Need a massive westward shift on that lot... For me anyway 

[NUT]

Thursday, Friday and Saturday are our best chances up here looks like to me (3 days in a row)  Would say Friday more though as pressure looks too high on thursday

[Supacell]

21 hours ago, Supacell said:

GFS shows Monday as being a good day with some decent CAPE values and heavy precipitation across N and E England. BBC and Met Office are forecasting a dry day. So, I am confused.... I assume one will fall in line with the other at some point, probably tomorrow. Likelihood is that the GFS will fall in line with the Met Office. Then I am hearing mumurs of a thundery plume next weekend or thereabouts - a long way off but it has my ears pricked up at least.

 

Surprisingly the GFS is still showing an area of decent CAPE and heavy precipitation moving across the far north of England and south-east Scotland tomorrow afternoon and evening. WRF and NMM are also on-board. BBC, Met Office and Euro 4 are still forecasting it to be dry.

So, we are now less than 24 hours out and there is still a huge disagreement, although there is agreement that an occluded front associated with an area of low pressure to the NW of the British Isles will pass across central and northern areas from west to east. High pressure will be in charge across most of England and Wales and this ridging will prevent anything from being able to get going as the front passes. I would imagine it is the extent of this ridge that is causing the difference in the models. Using the NMM model which is from the Netweather Extra suite of models

Across the far north of England and Scotland the CAPE builds into the afternoon ahead of the occluded front as warm air is pulled northwards between high pressure to the east and low pressure to the west (temperatures widely into the 20's). At the same time light winds from the south converge with light winds from the SW across a similar area

The NMM high res precipitation forecast shows a line of intense precipitation which moves from west to east (maybe storms) in an area whereby there is a lot of moisture present in the atmosphere (PWAT values in the upper twenties). So large rainfall totals in a short amount of time as the line of showers/storms passes through

Deep layer shear is evident, this would help any thunderstorms to organise as they develop and spread east. This is particularly strong towards the NE of England

Lightning Wizard, which is based around the GFS, even highlights this area as being at risk of supercell development

To my untrained, but experienced eye this looks like potentially the best storm potential so far this year and yet there is no talk on the subject. However, a massive caveat, this is purely dependant on the GFS/NMM/WRF being correct and the Met Office/BBC being incorrect. If the latter is correct then storms will not happen in England at least (the met office does show some precipitation across S and E Scotland tomorrow).

Edited May 21, 2017 by Supacell

[Windblade]

Bbc use met office data for their forecast as far as I'm aware. I've found the met office to be pretty rubbish really, very inaccurate in their forecasts so anything the bbc says I'd take with a pinch of salt. 

I find netweathers own forecast to be much more accurate, as well as convectiveweathers, and I'd be much more inclined to go with actual storm weather forecasting sites than the mainstream media/tv forecasts who all seem very conservative and reluctant to forecast storm activity (and even when they do they usually get it totally wrong).

As for this possible plume event, we had similar setups multiple times last year and every single time all the south east got was a baking hot, sticky, stinky, sweaty, miserable humid mess with not a drop of rain, while the rest of the country enjoyed numerous massive storms. The heat also lasted far longer in the south east than anywhere else, just to add insult to injury. It really was absolutely unbearable. I really, really hope that isn't the case this time.

Edited May 22, 2017 by Windblade

[Chris.R]

 Well there's been a few showers here already so it's not going the way the Met office forecast at the moment. 

[Windblade]

14 minutes ago, Chris.R said:

 Well there's been a few showers here already so it's not going the way the Met office forecast at the moment. 

I rest my case!

[Harry]

1 hour ago, Windblade said:

Bbc use met office data for their forecast as far as I'm aware. I've found the met office to be pretty rubbish really, very inaccurate in their forecasts so anything the bbc says I'd take with a pinch of salt. 

I find netweathers own forecast to be much more accurate, as well as convectiveweathers, and I'd be much more inclined to go with actual storm weather forecasting sites than the mainstream media/tv forecasts who all seem very conservative and reluctant to forecast storm activity (and even when they do they usually get it totally wrong).

As for this possible plume event, we had similar setups multiple times last year and every single time all the south east got was a baking hot, sticky, stinky, sweaty, miserable humid mess with not a drop of rain, while the rest of the country enjoyed numerous massive storms. The heat also lasted far longer in the south east than anywhere else, just to add insult to injury. It really was absolutely unbearable. I really, really hope that isn't the case this time.

We did have a fair few decent storms last year, Windblade. Maybe you weren't around at the time. Most of the plume related storms were very elevated affairs, thunder being particularly pathetic.

Also had a fair few thunder days during the day, although as I'm in the office I seldom get much opportunity to enjoy them.

I am hopeful this year will nevertheless be a good year. First semi-opportunity being later this week, however GFS already beginning to limit it and then shunt it eastwards. Still way out though so room for changes certainly. Now looking at 28C for Sunday 

[Darren Bown]

Met office seem to show showers breaking out in N England over the next few hours. Nothing on radar yet.

[Mokidugway]

Just now, Darren Bown said:

Met office seem to show showers breaking out in N England over the next few hours. Nothing on radar yet.

Cloud has rolled in nothing to convective though.

 

[Darren Bown]

8 minutes ago, Mokidugway said:

Cloud has rolled in nothing to convective though.

 

I've got quite dark cumulus to my west

[Mokidugway]

Nothing that foreboding,lol small trough feature over Merseyside though .

Edited May 22, 2017 by Mokidugway

[Allseasons-Si]

8 minutes ago, Darren Bown said:

I've got quite dark cumulus to my west

i see them on here developing from NE Wales northwards

http://beta.meteoradar.co.uk/satellite-rainradar#

whether they turn out to anything,we will have to wait and see.

[Mokidugway]

There does appear to be convergence there.

[Allseasons-Si]

3 minutes ago, Mokidugway said:

There does appear to be convergence there.

Have you got charts Moki,i cannot find them?

 

[Mokidugway]

Just now, Allseasons-si said:

Have you got charts Moki,i cannot find them?

 

On  xc  weather http://www.xcweather.co.uk/

[Allseasons-Si]

Just now, Mokidugway said:

On  xc  weather http://www.xcweather.co.uk/

Yes i have been looking at that,are you looking at those red SW arrows N of Wales running into the S arrows over Merseyside?

[Mokidugway]

Just now, Allseasons-si said:

Yes i have been looking at that,are you looking at those red SW arrows N of Wales running into the S arrows over Merseyside?

Yep  

[Allseasons-Si]

2 minutes ago, Mokidugway said:

Yep  

Gotcha

there are some CZ charts somewhere but cannot remember what site

sferics in Galashields SE Scotland.

Edited May 22, 2017 by Allseasons-si