Convective Storm/Discussion thread - 11/06/16 onwards

[Mapantz]

I'm not saying this is correct by any means, just going by it as a guide:

  

The storm risk seems to be on par with what convectiveweather.co.uk think.

I still remain very sceptical about anything in the SW (England)

[Greeny]

9 minutes ago, Mapantz said:

I'm not saying this is correct by any means, just going by it as a guide:

  

The storm risk seems to be on par with what convectiveweather.co.uk think.

I still remain very sceptical about anything in the SW (England)

Its all for the melting pot

[Chris.R]

Is this setup like  2 August last year? I got a nice storm from that and it seemed to be a complex frontal  situation as well  but it wasn't forecast. 

 Sorry not last year 2014. 

Edited June 27, 2016 by Chris.R

[Mapantz]

11 minutes ago, Greeny said:

Its all for the melting pot

Whenever there's a big set up, I usually get nothing. It's the surprise situations that something occurs here, when not much is on offer. lol

[Greeny]

10 hours ago, Mapantz said:

Whenever there's a big set up, I usually get nothing. It's the surprise situations that something occurs here, when not much is on offer. lol

I think the latest run from GFS has downgraded only slightly with the strongest shear more focused for the southwest than the previous forecast but lightning wizard and its SRH seems to have upgraded a little with its 12z and 15z, falling considerably by 18z.

[liamtellis]

Well we did have to some lovely altocumulus clouds in Cardiff this morning...

[Windblade]

Same here...

[East_England_Stormchaser91]

14 hours ago, William Grimsley said:

I think your reply is a bit screwed up. PWAT values itself don't effect lightning amounts, but higher PWAT values can leave you saying "Why isn't this cell electrifying?!"

Not sure. I'd have thought it would aid lightning amounts as the overall resistance through the air from cloud to ground is decreased making it easier for electrical conductivity, given that cloud tops are at a favourable height. Maybe I'm wrong? 

Edited June 28, 2016 by East_England_Stormchaser91

[weather09]

Useful link on precipitable water and its relevance to storms: http://www.theweatherprediction.com/habyhints/294/

Think some are looking too deeply into this.  CAPE and updraft speed determines lightning amounts/frequency.  PWAT simply tells you how moist the profile is. Moisture is key to good storm development, however high moisture can lead to the issue of 'water loading', where high volume of water and intense rainfalls can slow updraft speed which can have a noticeable effect in weaker CAPE environments, where in the the initial stages of storm development you'll get some lightning, but then intense falls of rain quickly stifles the updraft. But in environments of high CAPE, this isn't an issue, but does mean that CAPE alone won't tell the whole story concerning potential updraft strength.  In the real world, many factors influence updrafts.  

Edited June 28, 2016 by weather09

[Chris.R]

8 minutes ago, weather09 said:

Useful link on precipitable water and its relevance to storms: http://www.theweatherprediction.com/habyhints/294/

Think some are looking too deeply into this.  CAPE and updraft speed determines lightning amounts/frequency.  PWAT simply tells you how moist the profile is. Moisture is key to good storm development, however high moisture can lead to the issue of 'water loading', where high volume of water and intense rainfalls can slow updraft speed which can have a noticeable effect in weaker CAPE environments, where in the the initial stages of storm development you'll get some lightning, but then intense falls of rain quickly stifles the updraft. But in environments of high CAPE, this isn't an issue, but does mean that CAPE alone won't tell the whole story concerning potential updraft strength.  In the real world, many factors influence updrafts.  

 Thanks W09, :-)   Basically what I thought then but with the  consideration of water loading. 

[Azazel]

complex set-up today, so my map looks like a picasso painting but these are the areas I would go for.

 

 

[William Grimsley]

Nothing really much happening here except there was some huge drops on the way back from Exeter about 10 minutes ago.

All of a sudden dark to the west, maybe those huge drops are about to slam down?!

Edited June 28, 2016 by William Grimsley

[Greeny]

1 hour ago, weather09 said:

Useful link on precipitable water and its relevance to storms: http://www.theweatherprediction.com/habyhints/294/

Think some are looking too deeply into this.  CAPE and updraft speed determines lightning amounts/frequency.  PWAT simply tells you how moist the profile is. Moisture is key to good storm development, however high moisture can lead to the issue of 'water loading', where high volume of water and intense rainfalls can slow updraft speed which can have a noticeable effect in weaker CAPE environments, where in the the initial stages of storm development you'll get some lightning, but then intense falls of rain quickly stifles the updraft. But in environments of high CAPE, this isn't an issue, but does mean that CAPE alone won't tell the whole story concerning potential updraft strength.  In the real world, many factors influence updrafts.  

Yeah thats a good website w09. Thanks for posting the link for PWAT its good info.

I think a good example of high PWAT keeping lightning to less than expected was here in Norfolk last thursday the 23rd. Although it was hot in the cloud breaks and was humid, DPs of around 20C, cloud cover kept the build up of CAPE to less than what was expected if clouds were not so in abundance.  Before it hit V4 radar realtime overlay stated 600j/kg of CAPE. The outcome were floods and some lightning with the odd loud cracks of thunder but lightning wasn't as frequent as it could have been if either CAPE was allowed to build up more or PWAT values were a bit less.

 

Edit: this was within the period where there was strong DLS in the mix.

Edited June 28, 2016 by Greeny
added DLS

[Windblade]

I still have acas and also cumulus but sadly no towers going up. My area was not forecast for anything though so I'm not exactly hoping for things that ain't gonna happen. The risk looks minimal for the rest of the week for me, so I doubt there will be any action until next week possibly, depending what happens in the setup of course.

Edited June 28, 2016 by Windblade

[William Grimsley]

Nice hook to the low as it moves towards Cornwall (looks like a developing sting jet but isn't). Will be interesting to see if anything kicks off in that region soon.

@Greeny, am I right in saying that highest risk of anything interesting today is funnel clouds and the odd tornado and to a lesser extent lightning?

Wind gusts nearly touching 70 mph in the Irish Sea?!

Edited June 28, 2016 by William Grimsley

[Chris.R]

 Just have an immense squall go through  with torrential  convective rain and gusty winds. Sferics around now. 

[Bridgehill Blizzard]

Thunder and lightning now in Consett, Co Durham

[Bridgehill Blizzard]

Now hail, thunder and lightning!

[Pursuer of Storms]

Interesting skies over MK earlier. A sign of what's to come? 

Edited June 28, 2016 by Pursuer of Storms

[William Grimsley]

Very windy here, winder than expected, trees looked like they were going over earlier on!

[Mapantz]

45 minutes ago, William Grimsley said:

Nice hook to the low as it moves towards Cornwall (looks like a developing sting jet but isn't). Will be interesting to see if anything kicks off in that region soon.

@Greeny, am I right in saying that highest risk of anything interesting today is funnel clouds and the odd tornado and to a lesser extent lightning?

Wind gusts nearly touching 70 mph in the Irish Sea?!

Not sure where you are getting 70mph from, highest gusts are in the cairngorms at 65mph. At lower levels, top gust is 42mph.

[William Grimsley]

Quite local to here and occured in a very similar setup to today: https://en.wikipedia.org/wiki/The_Great_Thunderstorm

[William Grimsley]

Just now, Mapantz said:

Not sure where you are getting 70mph from, highest gusts are in the cairngorms at 65mph. At lower levels, top gust is 42mph.

Erm? If you look at XC Weather you'll see a report earlier showing wind gusts of nearly 70 mph in the Irish Sea.

[Mapantz]

1 minute ago, William Grimsley said:

Erm? If you look at XC Weather you'll see a report earlier showing wind gusts of nearly 70 mph in the Irish Sea.

[William Grimsley]

Yes, not currently, but there was a result of nearly 70 mph. @Evening thunder, shall back me up!

It was Buoy 62023.

Edited June 28, 2016 by William Grimsley