Upcoming Convective / Storm Risk Discussion - w/c 12th May

[Summer Sun]

Well apart from an area heavy showers and a lightening strikes around the Dundee area its all quite across Scotland so far

 

The severe weather warning for the thunderstorms expires at 20:00

[Cheese Rice]

Sporadic bursts of rather big hail here, last literally a second then stops.

[lorenzo]

Couple of showers firing off along the CZ - pretty much stationary:

 

hiradarzoomv42.pl.png

 

Decent dewpoints on recent obs - pushing 60F where those showers have formed:

 

2013052013_uk_large.gif

 

...so quite a bit of moisture to play with there.

 

Hopefully it's an evening show rather than one of the late afternoon ones, a really humid, muggy, syrupy day, where the cloud breaks arrive the sun looks baking hot, it  must be cooking things up nicely above the grey canopy we have. Edit - Add Dewpoints, similar profile now across the Lothians from the profile W09 ident. earlier.

 

 

Most certainly has a Thundery feel, and it's one of those days where you hope that the atmosphere will need to balance the heat out a little by kicking off. Certainly hope so as don't fancy trying to sleep tonight in this heat !

Edited May 20, 2013 by lorenzo

[Coast]

Well apart from an area heavy showers and a lightening strikes around the Dundee area its all quite across Scotland so far

 

The severe weather warning for the thunderstorms expires at 20:00

 

- and it looks like the Skew T soundings fizzle out before then anyway. This may be a bust today, but then it wasn't set for an odds-on certainty this morning. Still, 4 hours+ to go and maybe someone will get a nice surprise.

[NUT]

Sun's back out here (after disappearing for a couple of hours) whether that adds more juice to the atmosphere who knows

[lorenzo]

Moisture won't hang around for long over Scotland, Lorenzo, with drier/cooler low-level air mass advecting from the north from 18Z, so conditions shouldn't be too uncomfortable for good night's sleep lol.

 

Pity Northerly air masses dont compute with hungry 6 week old babies  !!!

[Supacell]

Precip loading could be stifling those updrafts as electrical activity has been, so far, rather low. Moisture is decent, but that's not necessarily a good thing if CAPE and potential updraft speeds are low as they're dragged downward with intense rainfall. Mid-level lapse rates aren't particularly steep either, so a struggle overall.

 

I think it will be the volume of water that could cause problems for SE Scotland as the downpours are only moving very slowly. Similar heavy rainfalls could be occurring across the spine of N England in the next few hours too, but disappointingly (for those who like T&L) it appears that electrical activity is currently suppressed to just the odd flash and rumble.

[The PIT]

Expected a bit more activity over the Pennines but at the moment looks like a duff call by the Met office. Need a bit of sun.

[Convective]

Very strange here.. wind was only forecast to be around 13-19mph this evening but has suddenly jumped up to a constant speed of 29mph with gusts of 45mph!

[lorenzo]

Good call W09, Supacell, regional thread reporting torrential downpours for SE Scotland.

 

To be fair to the Met Office the warning matrix did not shout about High Impact / High Likelihood.

 

Disappointing not to have the T&L today, but still a good deal of interest weather wise today, some stunning cloudscapes hidden away behind the grey veils.

 

Skies thicker and darker now, only a little rain here but what rain it was of the golf ball sized rain drops variety.

[Convective]

Ah not too sure! Nice little cell starting up northwest of Hull and moving southeast slowly! Gaining intensity too!

 

EDIT: Aaannnnnnndd...... it's gone again!

Edited May 20, 2013 by Convective

[Mapantz]

To be fair to the Met Office the warning matrix did not shout about High Impact / High Likelihood.

 

The second from top orange box was checked though, confidence must have been fairly high for that to have been checked.

[lorenzo]

The second from top orange box was checked though, confidence must have been fairly high for that to have been checked.

 

Didn't spot the amber one? Was looking at the one below?

 

Must admit the news story on BBC Scotland looked like a bit of a Ramp!

 

Incase you never wander into the Regional Threads, here are some pics from this afternoon and evening. Close but no Cigar about sums it up !

 

Edited May 20, 2013 by lorenzo

[Summer Sun]

Didn't spot the amber one? Was looking at the one below?

Capture.PNG

 

Must admit the news story on BBC Scotland looked like a bit of a Ramp!

 

Incase you never wander into the Regional Threads, here are some pics from this afternoon and evening. Close but no Cigar about sums it up !

 

 

Yes there was an amber warning out to 20:00 but they removed it early

[Alex95]

Large rain drops falling in Newcastle but its nearly dark. The radar looks interesting to say the least!

[Cloud 10]

Large rain drops falling in Newcastle but its nearly dark. The radar looks interesting to say the least!

 

 

Might just squeeze a crack of thunder out of it,certainly  a long shot though!

 

[Convective]

That system has definitely fired up recently as it approached Newcastle. Maybe there will be a rumble or two!

[paul m]

We may be in for some rain if it continues on that track

[Coast]

Not (unfortunately) surprised to see yesterday's small potential come to nothing as it was marginal at best and I don't think the sun started heating things up until the convective ingredients had started to back down?

 

Can't see anything of note for us today in the charts, in fact it looks quite quiet for a few days generally and then starts to pick up in the North next Wednesday according to the current GFS free atmosphere chart:

 

[Coast]

Way off in the land of never-never (FI) I'm keeping an eye on how this develops and fluctuates over the next week of runs, a smidgen to the North and......

 

[Thundery wintry showers]

Convective potential for Thursday in NE England down to Lincolnshire is being eroded by a deepening of the North Sea low and intensification of an associated "wrap-around" front:

http://cdn.nwstatic.co.uk/gfsimages/gfs.20130521/06/60/h500slp.png
http://cdn.nwstatic.co.uk/gfsimages/gfs.20130521/06/60/ukprec.png

 

Although the GFS is almost certainly overdeepening the low, UKMO and ECMWF have also toned up this low pressure system.

[Supacell]

Actually feels more thundery out there today than it did yesterday with hazy sunshine making it feel warm and humid. Of course it matters not as there is no chance of seeing anything today.

[Karl83]

The closest I'm gona get to a storm at the moment is by watching the Netweather Live Stream! However, next Tuesday & Wednesday (dare I say it) look ok at the moment! :-)

[Coast]

BBC Radio 4 news this morning with Nick Miller mentioning thunderstorms in the North and Scotland for later today. What do we think guys?

 

None of the dedicated storm sites have any forecasts out today so far. GFS overview for the day has nothing but some unseasonable snow in Scotland high ground possibly later:

 

 

ML CAPE in NE Scotland is OK, but not outstanding:

 

 

 

SB CAPE a bit better:

 

 

Convergence zones are scattered across the UK, more so down the Eastern side but the parcel layer depth is up in the very tippy top of NE Scotland:

 

 

Lift levels again in that area:

 

 

But very steep lapse rates may be what could trigger something this afternoon?

 

 

 

If it's going to happen it looks like the area around Braemar that's favoured, I'm staying reserved about it at the moment TBH and see what happens later on the radar and detectors.

[Nick F]

Can't see anything of note for us today in the charts, in fact it looks quite quiet for a few days generally and then starts to pick up in the North next Wednesday according to the current GFS free atmosphere chart:

 

Don't think it looks that quiet Robin, particularly tomorrow going by the Met Office forecasts, though nothing severe. I think GFS maybe not picking up the potential today and tomorrow, though it maybe because it is simulating alot of cloud cover suppressing convective potential.

Unusually cold 500mb cold pool (temps of -30C to -35C) extending SE across Nern and eastern Britain this afternoon, which could trigger some heavy showers accompanied by hail and thunder this afternoon across Scotland and eastern England. Though looking at the GFS CAPE charts you wouldn't think it, but lapse rates on forecast skew-ts certainly look steep enough across eastern Scotland and NE England for thunder.

This cold pool moves down across central and eastern England tomorrow, so scattered heavy showers likely to develop across England and Wales tomorrow, with a risk of the odd storm with hail over central and eastern England, where the air will be coldest aloft.

Edited May 22, 2013 by Nick F