Convective/Storm Discussion Thread - 8th July onwards

[Robbie Garrett]

3 hours ago, Harry said:

Not allowing myself to carried away just yet - 5 days is a bit a large window for variation for me.

Encouraged though by the consistency over the past couple of days - not very much in the way of variation between model runs, unlike previous plume periods this year where 00z to 06z to 12z to 18z have looked substantially different. 

The wind charts show clearly the thundery low developing over NW Spain as a cut off low Monday evening, drifting into the BoB before arriving across our shores around 21z-00z Tuesday/Wednesday. What will be interesting is what that fires across Spain/France/BoB as this will undoubtedly have a big impact on UK fortunes. The veering winds around the low will also help negate reliance on the jet (which at this time is non-existent across W Europe).

I am hopeful we will end up with something like we experienced 3/4 July 

 

 

Hoping for a BIG MCS  imported and ready to crack.

[Sparkiee storm]

4 minutes ago, Robbie Garrett said:

I clear the airport at 1455, so hopefully so.  I don't fancy flying through CB's and abeam TSRA's as it makes you feel sick!

Don't planes flying around storm clouds, if they are big enough? 

Edited July 14, 2017 by Sparkiee storm

[Robbie Garrett]

Just now, Sparkiee storm said:

Don't planes flying around storm cloud, if they are big enough? 

Well if it doesn't show on radar as a huge red/purple blob you can go through the clouds. CB's are flown through all the time in jet's, although the more mature and dissipating ones are avoided.  It can be pretty bumpy flying near Thunderstorms due to the atmospheric conditions.

 

[Sparkiee storm]

3 minutes ago, Robbie Garrett said:

Well if it doesn't show on radar as a huge red/purple blob you can go through the clouds. CB's are flown through all the time in jet's, although the more mature and dissipating ones are avoided.  It can be pretty bumpy flying near Thunderstorms due to the atmospheric conditions.

 

Oh okay and yeah that's understandable, must be quite the thrill though 

Edited July 14, 2017 by Sparkiee storm

[Dangerous55019]

Morning all 
Well here we are once again, staring down the barrel of yet another potentially thundery breakdown... So for consistency I am again using the latest 00z run from the GFS...  Lets start the ball rolling on this coming Tuesday...



The one thing that strikes me looking at these charts is that it looks to be an extremely promising event for the South West of the UK, but as always please check the Skew-T charts on the day as this could all still change. But at the moment, its looking good 
 

And now onto Wednesday...









Now then, I've covered all of Wednesday with these charts... Now then, the one thing that strikes me looking at these charts is that there is quite a discrepancy between the Cape/LI charts on the left and the storm risk charts on the right. But this is still five days away, so I'm not too concerned about this at the moment, as potential showing is potential showing.
As always check the Skew-T charts on the day and also use storm radar, now casting, praying to the weather gods etc nearer the time.
But fingers crossed that this could hopefully be the 'BIG' thundery breakdown that so many of us are craving. 

[Chris.R]

Hi everyone.

Well here I am again, in Holyhead for the week camping. I wonder if I can get a storm  exactly a year to the day of that  amazing overnight beast when I was here last year.  Have to admit I'm getting a bit of  déjà vu. Some of you might remember my slightly crazy posts during last years storm here, it was something special. Anything remotely near that again would be amazing. .  

[RichmondWeather]

Just wait as it all moves to not even clip the kent coast. I can see that coming, no matter what the models say.

[AL.]

Fingers crossed yet again here in Swindon, I wait in hope! 

[Harry]

31 minutes ago, RichmondWeather said:

Just wait as it all moves to not even clip the kent coast. I can see that coming, no matter what the models say.

Not so sure this time round @RichmondWeather - time will tell however

[Mokidugway]

Well , it's a grand day for November,sorry July ,wall to wall mongooseing drizzle  more chance of convection on the Antarctic plateau than here  

[Dami]

I have flown from LA to Hawaii during a thundery outbreak. Plane would should feel like it was dropping, there was a bang then a woman would scream. Most of the people on board were busy reading, although a few were trying to calm the woman down. me? Looking at the tops of all the thunder heads out the window.

But yeah it's kinda scary. 

Edited July 15, 2017 by Dami

[wimblettben]

20 minutes ago, Harry said:

Not so sure this time round @RichmondWeather - time will tell however

A lot of models in the past with thundery events have shown widespread thundery activity only for it to be reduced to isolated events with the main activity further northeast of most locations.

Seen it happen numerous times already this year so my expectations aren't very high at the moment.

[Chris.R]

51 minutes ago, Mokidugway said:

Well , it's a grand day for November,sorry July ,wall to wall mongooseing drizzle  more chance of convection on the Antarctic plateau than here  

 Well here on the north-west tip of wales it's blazing sunshine so that's the forecast an epic fail again. Nice start to my holiday anyway. 

[Chris.R]

55 minutes ago, Mokidugway said:

Well , it's a grand day for November,sorry July ,wall to wall mongooseing drizzle  more chance of convection on the Antarctic plateau than here  

 Well here on the north-west tip of wales it's blazing sunshine so that's the forecast an epic fail again. Nice start to my holiday anyway. 

[LightningLover]

During my holiday, if there is any thunderstorms, ill try to keep you updated. Since there will be no internet (it's one of those activity-based PGL trips), ill be using 4G. 

[Mokidugway]

43 minutes ago, Chris.R said:

 Well here on the north-west tip of wales it's blazing sunshine so that's the forecast an epic fail again. Nice start to my holiday anyway. 

Ok Chris I get the message ,lol

[Julian 777]

55 minutes ago, LightningLover said:

During my holiday, if there is any thunderstorms, ill try to keep you updated. Since there will be no internet (it's one of those activity-based PGL trips), ill be using 4G. 

Good luck for Tues/Wed night...Current indications look encouraging.If you strike lucky on IOW then at least I can see it from here and I'll settle for that.

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Sun 16 Jul 2017 - 05:59 UTC Mon 17 Jul 2017

ISSUED 09:40 UTC Sat 15 Jul 2017

ISSUED BY: Dan

... SHETLAND ...

Upper trough sliding east will graze the Northern Isles on Sunday afternoon and evening, with cool air aloft helping to steepen mid-level lapse rates. Some isolated lightning will be possible from scattered showers, perhaps organised along a shortwave trough during the second half of the afternoon.

... MIDLANDS / EAST ANGLIA / HOME COUNTIES ...

Residual low-level moisture from weak cold front slowly drifting south, combined with some convective overturning / insolation, may allow a couple heavy showers to develop on Sunday afternoon/early evening. Overall convective depth considered too shallow for lightning, and so no LOW threat level included for now.

http://www.convectiveweather.co.uk/forecast.php?date=2017-07-16

[samadamsuk]

Hi All,

Tuesday night Wednesday does look interesting - current 0.5 GFS models look to bring in a 50-60 kmh southerly at 500mb Tuesday night across the south coast, and with 950mb winds ese and quite strong helicity values of 200-275 m2/s2. As usual monster cape is across the channel but some ok LI's moving in at the same time so lapse rates looking okish. Actual jet stream winds don't look too great from what I can see, so for mcs propagation and interesting storm modes and structure it looks marginal to me. Dew points look juicy so looking good for something surface based. 

I'm thinking driving from Cirencester to Durdle Door for an evening swim, then setting up the camera for a light show!

 

Samos

 

[Mapantz]

2 hours ago, wimblettben said:

A lot of models in the past with thundery events have shown widespread thundery activity only for it to be reduced to isolated events with the main activity further northeast of most locations.

Seen it happen numerous times already this year so my expectations aren't very high at the moment.

That's probably down to looking at the lower resolution charts. Widespread thunderstorms, while not rare, don't happen that often, they are more likely to be isolated. If you read back through all the warnings and advisories given out by various convective forecasts over the last few months, you'll be hard-pushed to find a sentence with 'widespread' included in it.

[wimblettben]

15 minutes ago, Mapantz said:

That's probably down to looking at the lower resolution charts. Widespread thunderstorms, while not rare, don't happen that often, they are more likely to be isolated. If you read back through all the warnings and advisories given out by various convective forecasts over the last few months, you'll be hard-pushed to find a sentence with 'widespread' included in it.

True, I need to stop looking at low resolution charts then giving me false hope. 

But regardless this coming spell is already becoming a bit confusing as its not clear to whether we will be getting a front of storms coming up from the South-Southwest or having to rely on isolated home grown ones.

[LightningLover]

Good luck to Brighton, too!

[Summer Sun]

Day 4 Convective Outlook

VALID 06:00 UTC Tue 18 Jul 2017 - 05:59 UTC Wed 19 Jul 2017

ISSUED 14:06 UTC Sat 15 Jul 2017

ISSUED BY: Dan

Negatively-tilted Atlantic trough will slowly approach from the west on Tuesday - on its forward side, advection of a high WBPT airmass will occur from Biscay/France into southern Britain. This, combined with falling heights aloft, will aid destabilisation of the mid-levels through isentropic lift.

Given the lead time, there will undoubtedly be some uncertainty as to the exact forecast evolution (even on the day of the event, let alone some 4 days in advance!), but a broadbrush approach has been adopted for now to highlight some reasonable consistency amongst various NWP guidance. Upgrades to SLGT and perhaps MDT are likely as confidence improves nearer the time.

Current thinking is elevated thunderstorms will begin to develop on Tuesday afternoon over northern France / Channel Islands / English Channel, and then drift northwards in some fashion to S/SW Britain, continuing N or NE through the evening and overnight across portions of England and Wales, and perhaps the Republic of Ireland also. The exact track, coverage and timing rather uncertain at present, as one would expect. Given the magnitude of CAPE and steep mid-level lapse rates, lightning will likely be frequent where thunderstorms occur.

http://www.convectiveweather.co.uk/forecast.php?date=2017-07-18

[Mapantz]

Interesting looking at some of the model output.. there's a risk that it could be a lot further West, and therefore affecting western counties, and running straight up through the Irish sea. I seem to remember something similar happening in 2014 - I think? It looked promising for Southern counties, then it all shifted West, and I think @Convective had some good activity on the IoM.

[Ross Andrew Hemphill]

I honestly better get some storms from this, no one understands the frustration of this horrible summer so far with no heat and no storms!