Convective / Storm Discussion - 28th July onwards 2013

[wimblettben]

Today has been much different than yesterday.

 

Light to moderate rain in the morning has cleared to sunshine and cloud. No thunder heard from any of the rain.

 

After all of the thunder I heard yesterday, I wouldn't be too bothered if I didn't have anything else for the rest of the year now, though this doesn't mean I wouldn't want more if I could.

[stainesbloke]

Really not liking the latest GFS run. Pretty much removes the thunderstorm risk from England and Wales from this upcoming end of the week plume with our friendly European neighbours getting the action again.

Really? What's changed? Was hoping to see something Fri as missed the action last week, last weekend and yesterday! Grrrr

[Costa Del Fal]

Looks like plenty of Cape on Thusday but people must not fall for this. You need to look at the other parameters. There looks to be very little ppn indicating too much CIN capping storms from breaking out hence why there isnt really any thundery risk for the rest of this week imo.

[Supacell]

Looks like plenty of Cape on Thusday but people must not fall for this. You need to look at the other parameters. There looks to be very little ppn indicating too much CIN capping storms from breaking out hence why there isnt really any thundery risk for the rest of this week imo.

 

My thoughts exactly. CAPE good on Thursday but by Friday when there is less of a cap and more chance of precipitation all the energy is to the east of the UK. Still just one run though and its 72 hours away, Friday could be brought back into the frame yet.

[cheese]

Looking at GFS, I really don't see significant levels of CIN on Thursday until 11pm or so when it doesn't really matter anyway.

Edited July 30, 2013 by cheese

[Costa Del Fal]

Looking at GFS, I really don't see significant levels of CIN on Thursday until 11pm or so when it doesn't really matter anyway.

If your looking on meteociel then take note that the times are in European time and thus I believe 11pm on the charts actually equates to about 9pm here so from a plume event id say the CIN develops at a bad time to affect storm development im afraid. 

[cheese]

I think times are for Central European Time (i.e France) so would be 10pm. Regardless, it doesn't develop until after peak heating so I think there is a chance of something developing on Thursday afternoon. I guess we'll just have to see, plenty of chopping and changing to come I'm sure. The high-res NMM model on Meteoceil also shows low levels of CIN until Thursday night. Not sure how reliable it is in terms of convection.

Edited July 30, 2013 by cheese

[Snowshine]

Today was better than yesterday! Caught 2 showers but no thunder.

Tommorow looks intresting, the CAPE should reach 550j/kg with an LI of -2 and showers are forecasted so looks like a thunderstorm may pass by, unless the storm shield decides to push the storms away, I will be keeping track where the storms go tommorow!!!

This looks like the last chance to actually catch a storm, Thursday looks sunny/cloudy for all the UK except Northern Ireland or Northern Scotland, if there was rain it could have bought some fairly big storms! East England might catch one on Friday. No rain likely next week

[Tim Bland]

Love how people dispair after 1 GFS run! The storm risk on Fri is high enough for the met office to issue early warnings and the 06z was great for storms. Wait for a few more runs before getting worried IMO

[Cloud 10]

I'm still hopeful for Thursday,plenty of fuel in the tank,but will the engine start? 

 

[poseidon]

Some pictures I took out and about yesterday in Herts and Essex....

 

https://forum.netweather.tv/gallery/image/18773-tcu-going-up-in-herts/

 

A bit of mammatus...

 

https://forum.netweather.tv/gallery/image/18772-cell-with-mammatus-and-rainbow-foreground/

 

https://forum.netweather.tv/gallery/image/18767-shower-cloud-undergoing-convection/

 

https://forum.netweather.tv/gallery/image/18763-taken-from-the-car/

 

Think this is a flanking line (with anvil in the background). Cell moved up from London, with torrential rain and a bit of thunder and lightning...

 

https://forum.netweather.tv/gallery/image/18758-another-view-of-the-london-storm/

 

https://forum.netweather.tv/gallery/image/18757-rear-flanking-line-with-the-anvil-behind/

 

This looks to me like a shelf cloud. CG lightning was produced to the rear of this...

 

https://forum.netweather.tv/gallery/image/18742-shelf-cloud/

 

https://forum.netweather.tv/gallery/image/18740-shelf-cloud-of-thunder-storm-in-herts/

 

https://forum.netweather.tv/gallery/image/18743-cloud-hanging-from-below-thunderstorm/

 

Any extra insight regarding the features visible in the pictures of the London cell would be much appreciated. More pictures from yesterday in my gallery.

 

[Darren Bown]

Just had an absolute downpour. Totally unexpected! No thunder or lightning though.

[Utahraptor]

I got yesterdays storms caught on video here in Down, Northern Ireland.

 

 

Got a nice still of a lightning strike too from the video.  

[Evening thunder]

Not sure if this is the best place to post this, but yesterday we had a few heavy showers here but when it became clear we were unlikely to get any thunderstorms here I thought sod it, I'm off east so went on a chase. I set off about 2:45pm and was actually successful in finding some action and had 3 separate thunderstorms! I ended up near Westbury, though worked out if I had set off this morning I could have had thunderstorms all day in an area south/SE of Bristol without moving much!

 

The first cell was near Wincanton, Somerset. I was unable to get pictures of this storm when driving, but this was it as it moved off:

 

However off to the north convection was building nicely, and growing into nice Cumulonimbus clouds. Each pic slightly after the previous:

 

I didn't actually think I would go for these (was gunna go south a bit and incase showers further west intensified) but did go towards them in the end.

 

From a different position further NE, this point frequent thunder was coming from this Cb (that didn't fit in the cameras field of view):

 

Closer to the storm, thunder not so frequent though:

 

After this I was under some heavy rain with thunder and lightning at times from the storms and got stuck in traffic that seemed to be caused by a traffic light system not working near Frome or Trowbridge (maybe caused by lightning?)

These are those storms moving off:

 

New convection had been forming a CB on the back of the other cells and was producing occasional thunder by this point:

 

Close up of its convection:

 

some convection to my north on the back side of the cells moving off looked interesting as it seemed to form into a shape that makes it appear the updraught might have been rotating to some extent, with an interesting lowering that I thought could it be trying to form a funnel but thought might be scud at the time. Looks interesting on photos though.

 

a zoomed in image, the lowering to the left of the tree looks possibly suspect, with the sun shining on the end of it? this image was actually taken just before the one above.

I don't think it lasted long though.

 

Funnel or scud, would be interesting to see what others think?

 

A 3rd storm was forming and producing well defined rain shafts:

 

I moved a mile or so further east where this gave pretty intense rain and the wind picked up, though I have this on video not pictures.

It did cause some flooding of lanes though:

 

The 3rd storm moves off:

 

After this a new heavy shower formed near sunset:

  

 

 

I also saw on the way home one main road through Westbury was closed due to flooding, didn't get a very good view but looked quite deep and a couple people were carrying an inflatable boat.

 

Also made a timelapse from home with a webcam taking images every 5 seconds, no thunderstorms but some convective showers and a nice sunset:

 

Oops I might have gone a bit over the top with the pictures lol. I missed most lightning for various reasons but did manage to capture one small bit on camera, which will only attatch below at the end of the post for some reason.

Edited July 30, 2013 by Stormmad26

[Harry]

Not sure it's been posted yet - MetO issued early warning for the SE for thundery rain (though confidence is low).

Very odd yellow zone marked IMO

[Severe Blizzard]

Not sure it's been posted yet - MetO issued early warning for the SE for thundery rain (though confidence is low).Very odd yellow zone marked IMO

This will be the one at Guildford having missed out big time over the last few days and with 28.3 mm falling at FLEET, HANTS yesterday.Why?Because I will be staying at Fleet overnight Fri-Sat and that will be when Guildford gets the long awaited deluge and storm. Bl**dy typical of the bad luck I have had with missing out in the last 15 months or so. If I cancelled the trip - the warning would go the way of all the others in the last few weeks - bust.

[Utahraptor]

 
I managed to get another storm today in NI. It had a fairly nice structure to it, but it wasn't anything overly special. Looking forward to this Friday when the CAPE where I am looks like it will be the highest. Fingers crossed!

 

Edited July 30, 2013 by Utahraptor

[Karl83]

I got yesterdays storms caught on video here in Down, Northern Ireland.

 

 

Got a nice still of a lightning strike too from the video.  

Nice shots! I am amazed you can see into the future :-)

[Utahraptor]

Nice shots! I am amazed you can see into the future :-)

Haha I caught that mistake xD I fixed it now

[Supacell]

Early start for me today but I did mention yesterday that there may just be a possibility of some thunderstorm activity behind the northward moving warm front. If something does develop it will bring with it a scope for some torrential downpours and the risk of a tornado. It appears Skywarn have noticed this same potential

 

Severe Thunderstorm Watch #27 issued effective 10z

SKYWARN UK SEVERE THUNDERSTORM WATCH #027
ISSUED: 0100UTC WEDNESDAY 31ST JULY 2013

SKYWARN UK FORECASTS THE POTENTIAL FOR SEVERE THUNDERSTORM CONDITIONS AS FOLLOWS:
HEAVY RAIN LEADING TO A RISK OF LOCALISED FLOODING - WALES, MIDLANDS & NORTHERN ENGLAND
STRONG, POTENTIALLY DAMAGING WIND GUSTS - MIDLANDS & NORTHERN ENGLAND
BRIEF POTENTIALLY DAMAGING TORNADOES - MIDLANDS

IN EFFECT FROM 1000UTC UNTIL 2000UTC WEDNESDAY 31ST JULY 2013

WARM FRONT ADVANCING NORTHEAST WITH A MOIST AND SLIGHTLY UNSTABLE AIRMASS, IN A FAVOURABLE SHEAR ENVIRONMENT FOR ORGANISED THUNDERSTORMS

DISCUSSION:
THERE IS FAIR MODEL AND PARTNER AGENCY CONFIDENCE IN THE POSSIBILITY FOR SEVERE THUNDERSTORM RISKS DURING THIS PERIOD. A LOW TO THE WEST ENCOURAGES A WARM AND VERY MOIST AIRMASS NORTHEASTWARD, GENERATING AMPLE DEEP MOISTURE CONVERGENCE AND HIGH SURFACE DEWPOINTS THROUGH WALES AND THE MIDLANDS. WHILE THE FRONT ITSELF IS STABLE DUE TO PRIOR CLOUD COVER, SPARSE BREAKS BEHIND MAY ALLOW FOR LOCALISED CAPE BUILD UP OF UP TO 1000J/KG IN THE MOIST ENVIRONMENT. THIS WILL FOSTER INSTABILITY IN A WELL-SHEARED ENVIRONMENT, WITH SUFFICIENT 0-3KM AND 0-1KM SHEAR FOR ORGANISED CONVECTION, STRONG GUSTS AND POSSIBLE TORNADOES. THE HIGH PWAT VALUES OF NEAR 4CM WILL ALSO ALLOW FOR INTENSE RAINFALL TO OCCUR WITHIN MATURE CELLS, POSSIBLY LEADING TO FLASH FLOODING OVER THE HIGHER GROUND OF THE WATCH AREA. THE LIKELIHOOD OF CONVECTIVE INITIATION IS DEPENDENT UPON THE FEED OF LOW LEVEL MOISTURE AND SUNSHINE, AND IS THUS ONLY CONDITIONAL AND NOT GUARANTEED. THIS WATCH MAY BE UPDATED OR UPGRADED. PLEASE MONITOR WEATHER AND TRAVEL INFO AS NECESSARY.

SPOTTER ACTIVATION IS REQUESTED AND SPOTTERS ARE REQUESTED TO REPORT ALL FACTORS EXCEEDING ACTIVATION CRITERIA.

 

www.skywarn.org

 

Maybe this will come together or maybe we're talking a day of cloud and rain.

[Jane Louise]

This way for a new thread Locking this one soon. 

 

http://forum.netweather.tv/topic/77434-convective-storm-discussion-31st-july-onwards-2013/