Storms and Convective Discussion - 25th June 2019 onwards

[Harry]

Interesting that the latest Euro4, NetWx and UKMO predictions all bring London and the SE into play between 00z and 03z.

First signs of some Ac forming overhead now but very benign and not remotely AcCas. 

Interesting...

All depends on how much the trough extends it’s big toe towards the east...

Edited July 23, 2019 by Harry

[Harsh Climate]

1 minute ago, Mitch perrott said:

well on the metcheck thunderstorm development radar it seems that the storm is infact heading north east earlier than expected

No storms have even developed yet 

[Mitch the motorbike storm]

Just now, Harsh Climate said:

No storms have even developed yet 

im not a storm chaser haha have mercy on me, im just going on what the radar is telling me xD

[Thunder and Lightning]

2 minutes ago, Harry said:

Interesting that the latest Euro4, NetWx and UKMO predictions all bring London and the SE into play between 00z and 03z.

First signs of some Ac forming overhead now but very benign and not remotely AcCas. 

Interesting...

All depends on how much the trough extends it’s big toe towards the east...

Bring me In!

[Flash bang flash bang etc]

3 minutes ago, Mitch perrott said:

well on the metcheck thunderstorm development radar it seems that the storm is infact heading north east earlier than expected

I want your eyes

[Karl83]

Beautiful sight 

[LionKingGamer]

I Mean this could be another big bust and something just doesn't click but that looks very unlikely. However im hoping for something over London/SE

[Summer Sun]

Day 1 Convective Outlook

VALID 06:00 UTC Tue 23 Jul 2019 - 05:59 UTC Wed 24 Jul 2019

ISSUED 20:00 UTC Tue 23 Jul 2019

ISSUED BY: Dan

UPDATE 20:00 UTC MDT expanded in size to highlight areas where lightning most likely to occur overnight. Any thunderstorms on the southern flank with unimpeded inflow (particularly in a zone from the West Country across the south and east Midlands) could produce very frequent lightning. SLGT also reshaped over Ireland based on latest guidance, though overall considered low-end here

An upper ridge will cover much of western and central Europe on Tuesday, its axis over Germany / Switzerland placing the British Isles in a south-southwesterly flow on its western flank. This will encourage gradual advection of a high Theta-W airmass northwards, with surface dewpoints up to 20C expected on Tuesday afternoon across England and Wales. An elevated mixed layer (EML) will over-run this very warm, moist low-level airmass, generally preventing any surface-based thunderstorms from developing.

Meanwhile, a shortwave rounding the largescale upper trough over the Atlantic to the west of Ireland will swing northeastwards, the associated falling heights and cooling aloft resulting in increasing instability over northern France and the western English Channel where 1,000 - 1,500 J/kg MLCAPE is possible by late afternoon and into the evening hours, locally up to 2,000 J/kg.

Convective initiation is expected mid/late afternoon over N France as a lead impulse encourages elevated convection to develop, these scattered showers/thunderstorms then drifting northwards into CS / SW England during the evening hours, riding the leading edge of the ThetaE ridge and ultimately marking the leading edge to the instability plume. Scattered elevated showers and thunderstorms will continue to develop and expand in coverage with each hour through Tuesday evening and night as they continue to migrate to the N or NNE - initially over CS / SW England, then affecting Wales / Midlands, northern England and eventually into Scotland later in the night. Other additional elevated showers/thunderstorms could develop on the eastern edge of the instability plume, and may affect parts of East Anglia and perhaps SE England.

The magnitude of CAPE/shear and very steep mid-level lapse rates suggests lightning will be very frequent at times. The environment will be conducive for thunderstorms to become locally severe, perhaps scope for one or two elevated supercells, capable of producing large hail - particularly during their early, more discrete stages before likely growing upscale into a mesoscale convective system (MCS) as they continue to drift farther north/northeast. Consequently, profiles will become increasingly saturated and instability will gradually weaken with time (and hence northward extent), and so a downward trend in lightning frequency is possible towards the end of the night. 

A SVR has been issued to highlight the threat of large hail. Rainfall is somewhat less of an issue in general, due to a combination of reasonably fast storm motion and some evaporation of rain due to dry layers beneath the thunderstorm base. However, should multiple showers/storms move over the same area, then localised flooding could also be an issue.

There is still some uncertainty over the exact track / coverage of thunderstorms during Tuesday evening / night, and some relatively minor changes may be necessary to the threat areas - including perhaps the introduction of a HIGH threat level if confidence improves (main focus at the moment is the West Country and south Midlands).

 

http://www.convectiveweather.co.uk/forecast.php?date=2019-07-23

[Mitch the motorbike storm]

Just now, Flash bang flash bang etc said:

I want your eyes

LMAO is that saying im delusional or very optimistic haha 

[Geordiesnow]

Feels like a waiting game at the moment, thought we may see a little more activity by now in fairness and the cloud heights on the satalite images look unimpressive atm. 

[Harsh Climate]

Anyone have any towers shooting up where they are, I want pictures 

[tomdewey]

I am still waiting hoping to see a thunderstorm this summer over here in Warminster in Wiltshire in South and West 

[Guest]

5 minutes ago, Lu. said:

Just pulled up. Sky to the right of me, yet to the left it’s totally clear. Very warm

Ha, which shelter is that lol!

[Flash bang flash bang etc]

3 minutes ago, Harsh Climate said:

No storms have even developed yet 

[Guest]

6 minutes ago, Lu. said:

Just pulled up. Sky to the right of me, yet to the left it’s totally clear. Very warm

Ha, which shelter is that lol!

[sunnijim]

Pre curser clouds arriving on Sussex coast

[Derecho]

I admit things have been quieter then expected so far, especially in the SW, some of the forecasts have already got this really wrong. Here is a forecast that was shown earlier compared to the current radar... hmmmm...

 

Activity is being pushed now back to around 11pm / 12pm now. So not ringing the alarm bells just yet but if by then things are still flat I will start getting concerned.

Edited July 23, 2019 by Quicksilver1989

[Flash bang flash bang etc]

1 minute ago, Mitch perrott said:

LMAO is that saying im delusional or very optimistic haha 

Both, you never know...

[ChezWeather]

Absolute BEAUTIFUL update from ConvectiveWeather there...

"UPDATE 20:00 UTC MDT expanded in size to highlight areas where lightning most likely to occur overnight. Any thunderstorms on the southern flank with unimpeded inflow (particularly in a zone from the West Country across the south and east Midlands) could produce very frequent lightning."

 

[Greeny]

15 minutes ago, Harry said:

I don’t think anyone is ruling out storms in the SE...just that the sky at the moment looks incredibly stable. I can see now some S-N running cirro-stratus looking clouds appearing to my west (and a rather large dragonfly zig-zagging about grabbing a late evening meal).

Ive never gone to sleep and had storms without even some signs of instability appearing now...I’ll happily be proven wrong however!

Perhaps not that great to go by but my weather app on my phone is suggesting storms tomorrow morning at 6am, Edit: here in Norwich

Edited July 23, 2019 by Greeny

[The PIT]

Convective weather always forget to put a circle round Sheffield where zero storms will occur.

[Mitch the motorbike storm]

Just now, ChezWeather said:

Absolute BEAUTIFUL update from ConvectiveWeather there...

"UPDATE 20:00 UTC MDT expanded in size to highlight areas where lightning most likely to occur overnight. Any thunderstorms on the southern flank with unimpeded inflow (particularly in a zone from the West Country across the south and east Midlands) could produce very frequent lightning."

 

Was i correct about it already moving south east....

[LionKingGamer]

Just now, Quicksilver1989 said:

I admit things have been quieter then expected so far, especially in the SW, some of the forecasts have already got this really wrong. Here is a forecast that was shown earlier compared to the current radar... hmmmm...

 

Activity is being pushed now back to around 11pm. So not ringing the alarm bells just yet but if by then things are still flat I will start getting concerned.

Well exactly. Last time everyone had their hopes up and it was the biggest failure of the year. Hopefully this materialises

[tomdewey]

[Harsh Climate]

And like some others have said things could go bang very quickly.  I remember a few years ago an evening like this with nothing happening and then booom! some massive storms kicked off with 300/min+ strike rates in space of under 30 minutes.  Think the one in guildford surrey was a supercell..