Storms and Convective Discussion - 20th April 2019 onwards

[matty40s]

7 hours ago, zmstorm said:

CAPE levels for Saturday 8th June. This day could see some thunderstorms in East Anglia, although this is still more than a week away so it could change.

Dark red is about 2,500+j/kg

This is the first time ever that I dont want thunderstorms, it's our marriage day and the reception is heavily outdoor based!

[Chris.R]

Sunday looks alright for me on the WRF 0Z. 600 J/KG CAPE and modest helicity and shear.  It also shows quite a bit of SBCAPE buildup Saturday evening but imagine that will be thoroughly capped.

Disappointed next weekend‘s plume seems to have gone on GFS.  

[Another Kent clipper]

3 hours ago, matty40s said:

This is the first time ever that I dont want thunderstorms, it's our marriage day and the reception is heavily outdoor based!

Congratulations!  You're only gutted because you might miss the lightning whilst having to mingle really

[Methuselah]

4 hours ago, matty40s said:

This is the first time ever that I dont want thunderstorms, it's our marriage day and the reception is heavily outdoor based!

Many congrats, matty...I hope all goes well!

[The PIT]

6 hours ago, matty40s said:

This is the first time ever that I dont want thunderstorms, it's our marriage day and the reception is heavily outdoor based!

Move your wedding to Sheffield and it's guaranteed storm free.

Congrats BTW you do realise since you don't want any you probably get the best storm of the century now.

[matty40s]

10 hours ago, Another Kent clipper said:

Congratulations!  You're only gutted because you might miss the lightning whilst having to mingle really

As most of its outdoors I might just give the mingling a miss and log on here instead 

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Sat 01 Jun 2019 - 05:59 UTC Sun 02 Jun 2019

ISSUED 20:15 UTC Fri 31 May 2019

ISSUED BY: Chris

An upper level trough and associated surface low will spread eastwards towards Ireland and western Britain on Saturday and into Saturday night. 

A broad warm sector will develop across Ireland and southern Britain on Saturday with temperatures rising widely into the 20sC (locally mid-20s in southeast England). However, this area will remain capped to convection throughout the period (and likely through much of Sunday as well). A cold front will begin to spread into western Ireland by late evening on Saturday and continue to move eastwards into the early hours of Sunday. The frontal forcing and associated PVA may tap into small amounts of mid-level instability (less than 200 J/kg of MUCAPE) and allow for some embedded convection along and just ahead of the cold front. If this occurs some lightning could be possible in the early hours on Sunday (0z-6z), however at this stage it is not expected to be very widespread. 

http://www.convectiveweather.co.uk/forecast.php?date=2019-06-01

[Swansonson69]

I'm finally back after my 1 year and 1 day ban for that fight last year. First of all I want to apologize to everyone involved including Paul (The guy who banned me). I also want to apologize to the guy I had a spat with. I've had time to think about what happened and it shouldn't happen again. 

Anyway onto storms since this is what this thread is about. So far this season I've had 2 storms and 1 thundery shower (1 flash, 1 bang wonder). Sunday might yield some storms for some hopefully. Not sure what happened to the potential on 6/7/8/9 June though. Seems to have disappeared. Today is very humid but capped. 

Edited June 1, 2019 by Swansonson69

[Swansonson69]

Definitely signs of instability here. Small towers going up to my south. Probably won't amount to anything though. 

[Harry]

Welcome back @Swansonson69 and good on you for your open and frank apology 

I think I’ve had one thunder day so far this year - which for a south-easterner is quite a quiet start to the year. Gorgeous, hot day today with some MUCAPE wafting up from France tonight (alas no trigger). Would put thunder threat at <5% for tomorrow however some diurnal activity possible next week which is nice!

Hoping for a proper plume soon - although my feeling at the moment is that it could be a 90s sort of year with some great bangers on August evenings/nights with some diurnal thundery showers at other times...we shall see!!

 

Edited June 1, 2019 by Harry

[Swansonson69]

2 minutes ago, Harry said:

Welcome back @Swansonson69 and good on you for your open and frank apology 

I think I’ve had one thunder day so far this year - which for a south-easterner is quite a quiet start to the year. Gorgeous, hot day today with some MUCAPE wafting up from France tonight (alas no trigger). Would put thunder threat at <5% for tomorrow however some diurnal activity possible next week which is nice!

Hoping for a proper plume soon - although my feeling at the moment is that it could be a 90s sort of year with some great bangers on August evenings/nights with some diurnal thundery showers at other times...we shall see!!

 

Yup. 

I'm a North easterner so it's been a good start so far as it's usually quiet at the start. 

Shame there's no trigger because I think the storms would of been pretty decent. 

I agree with you. I'm going for a hot and thundery summer this year which isn't bad at all. 

[Mapantz]

If I were to highlight a possible  area tomorrow, I would go for Lincolnshire up in to East and North Yorkshire. It'll be down to timing of the cold front, however, the FAX shows a trough ahead of the cold front.

[Swansonson69]

1 minute ago, Mapantz said:

If I were to highlight a possible  area tomorrow, I would go for Lincolnshire up in to East and North Yorkshire. It'll be down to timing of the cold front, however, the FAX shows a trough ahead of the cold front.

I agree with you on that one, you're right. It was me and you who had the argument last year. I'm sorry for that. 

[Swansonson69]

Looking at it now, it's a line of small towers to my south. 

[Another Kent clipper]

Batten down the hatches!  A venomous plume with no fangs

Day 2 Convective Outlook

VALID 06:00 UTC Sun 02 Jun 2019 - 05:59 UTC Mon 03 Jun 2019

ISSUED 18:52 UTC Sat 01 Jun 2019

ISSUED BY: Chris

A deep area of low pressure will move from west of Ireland towards western Scotland on Sunday with gales likely along its southeastern flank across northern parts of Ireland and into western Scotland. An associated cold front will also spread eastwards across Britain into a plume of unstable air, and a pre-frontal trough may help to tigger some convection within and just ahead of the frontal rain. 

ENGLAND and WALES

At 6z on Sunday an ongoing area of rain with embedded convection is likely to be stretched from southern Scotland/NW England through the Irish and Celtic Seas moving eastwards.  The best instability will be displaced from the before mentioned cold front, existing across E Anglia and SE England (up to 1,000 J/kg), and this area will likely remain capped by a layer of warmer air at around 800mb. Convective development in the deeper instability remains unlikely at this stage, although cannot be completely ruled out (one or two models have suggested an isolated heavy shower or thunderstorm may develop). 

As the cold front tracks eastwards forcing will become weaker and rain will become patchier, although some embedded convection remains a possibility along and just ahead of the front as it clears eastern England between mid-afternoon and late evening. An area through N-Cen / NE England is favoured for any more widespread lightning potential, and has the greatest potential for upgrade to slight. 

Northwestern IRELAND and western SCOTLAND

Behind the cold front and around and near the low centre, weak instability, but a moist and highly sheared environment may help to produce some heavier convection with the low end risk of lightning. Although mean winds will be strong, there would also be the small risk of an isolated tornado or two in this area in any stronger convection. 

With all of that stated, only a low risk of lightning seems appropriate at this stage, but we will continue to monitor trends for an upgrade if required. 

http://www.convectiveweather.co.uk/forecast.php?date=2019-06-02

[Swansonson69]

Here's hoping the cap gets broken tomorrow. 

[Harry]

Sat out in garden of our mates’ house in Medway - here’s the first sign of mid level instability advecting from the south (shame it’ll amount to nothing) 

[Swansonson69]

20 minutes ago, Harry said:

Sat out in garden of our mates’ house in Medway - here’s the first sign of mid level instability advecting from the south (shame it’ll amount to nothing) 

There's a lot of that around here. 

[Chris.R]

 Just had a moderate shower with large convective raindrops. Feels nice out here, a shame nothing is going to happen. 

6 times!

[TJS1998Tom]

Now obviously just for fun with it being two weeks away but wouldn't this be nice

[Swansonson69]

38 minutes ago, TJS1998Tom said:

Now obviously just for fun with it being two weeks away but wouldn't this be nice

3000J+ of CAPE would be enough to produce significant tornadoes if the other ingredients came together correctly. I'm waiting for an event with that amount of CAPE to happen. 

[East_England_Stormchaser91]

2 hours ago, Swansonson69 said:

3000J+ of CAPE would be enough to produce significant tornadoes if the other ingredients came together correctly. I'm waiting for an event with that amount of CAPE to happen. 

Not so sure. For this country, it would need to be perfect over such a short distance. Even in the US,I’m pretty sure it’s less than 20% of supercells actually produce tornadoes. Even they have their bust days with 4-5000j/kg CAPE. If there’s no trigger to break the Cap, it’s a wasted day! 

[Swansonson69]

17 minutes ago, East_England_Stormchaser91 said:

Not so sure. For this country, it would need to be perfect over such a short distance. Even in the US,I’m pretty sure it’s less than 20% of supercells actually produce tornadoes. Even they have their bust days with 4-5000j/kg CAPE. If there’s no trigger to break the Cap, it’s a wasted day! 

Quiet right my friend. There's got to be a repeat of the portsmouth 1874 EF4 tornado at some point (probably wrong on the date). You can have all the CAPE in the world but with no trigger it's wasted. Hoping for a trigger tomorrow. Mind you I saw a line of small towers of conviction to my south today which I didn't expect. 

[Another Kent clipper]

6 hours ago, TJS1998Tom said:

Now obviously just for fun with it being two weeks away but wouldn't this be nice

Now here's a question:. Why does the GFS do this?   I've seen a pattern of models showing craziness and then getting downgraded to nothing.  

Is there a particular reason or something that triggers the prediction.  And will a layman like myself understand the answer?!

[TJS1998Tom]

Can't see much in terms of thundery weather today