Convective/Storm Discussion Thread 25/5/16 onwards

[Ǝssex Ǝasterly]

Just now, Raidan said:

Has anyone else in or near bristol heard what sounds like faint rumbles it's probably not but I've heard it 3 times in the last 10mins while struggling to sleep.

Hungry? lol

[Raidan]

1 minute ago, Essex Easterly said:

Hungry? lol

Lol no its not my stomach I devoured a kebab earlier but seriously something is rumbling out there could be anything though.

[weather09]

Looks like tomorrow will see more in the way of scattered showers and storms, despite still being under a relatively weak upper ridge. Again, activity will be tied mainly to areas of light, converging low-level winds and increased elevation.  Main areas of interest look to be SW, Wales, N England, parts of Scotland (with perhaps a bias toward the western half of these regions where sea-breeze convergence set ups a little way inland), and NI. Several 100J/kg MLCAPE likely to build with heating of sufficiently moist air mass (dewpoints to mid-teens), so increased likelihood of some active storms where this instability is utilised. 

[Wilxy]

11 minutes ago, Raidan said:

Lol no its not my stomach I devoured a kebab earlier but seriously something is rumbling out there could be anything though.

Yeah I heard it as well sounded like fireworks to me?

[Raidan]

4 minutes ago, tomjwlx said:

Yeah I heard it as well sounded like fireworks to me?

[Raidan]

Could off been to be honest could do without a storm now need to be up at 4am but anytime after 2pm is fine.

[alexisj9]

37 minutes ago, Chris.R said:

 Ridiculously it's still 21.4°C. I'll struggle to sleep tonight. Desperately need a storm here. 

wow it's only 9.8 down here needed to put a light coat on to rush to the shop just now. Mind you the high here was 19.8, may be why. 

[Chris K]

38 minutes ago, Raidan said:

Has anyone else in or near bristol heard what sounds like faint rumbles it's probably not but I've heard it 3 times in the last 10mins while struggling to sleep.

I live about 10 miles N of Bristol and around a similar time there was a loud sounding aircraft (perhaps military) rumbling above in the distance somewhere not very far away. Seemed to hang around for a bit too. Perhaps it was that?

[Raidan]

5 hours ago, Chris K said:

I live about 10 miles N of Bristol and around a similar time there was a loud sounding aircraft (perhaps military) rumbling above in the distance somewhere not very far away. Seemed to hang around for a bit too. Perhaps it was that?

Quite possibly Chris seeing as 3 of us heard it and we live quite a distance apart it seems that could explain the rumblings. 

Today looks better for us storm wise we could see something today just hope it waits until I finish work.

[Bolt from the Blue]

A potent little cell near Calais has fired and heading NW, wonder if it'll make it across

[Nick F]

Storm & Convective Forecast

Issued 2016-06-06 06:10:38

Valid: 06/06/2016 06Z TO 07/06/2016 06z

DAY 1 CONVECTIVE FORECAST - MON 6TH-MAY-2016

Synopsis

A blocking upper omega ridge extends north through western and northern Europe on Monday, with a long wave upper trough to the west over the North Atlantic. A slack surface pressure pattern covers much of Europe, with a thermal low over the near continent a shallow high to the north of the U.K. and another over the Baltic Sea. 

... SW/S ENGLAND, WALES, N/W MIDLANDS, NW ENGLAND, N EIRE, N iRELAND, SCOTLAND ...

Mid to upper levels will be generally ridged/capped today, however, like last few days, weaker 500mb heights on western periphery of upper ridge and sea breeze boundary convergence plus orographic uplift across western and northwestern areas will break the cap locally to allow isolated or scattered heavy showers and a few thunderstorms to develop across parts of the above areas. Weak shear and lack of forcing aloft suggests pulse-type mode for storms, the slow storm motion and fairly abundant moisture pooling in convergence zones suggests high spot totals locally - bringing a risk of localised flooding. Storms maybe more widespread than yesterday, but given their localised nature and the lack of wind shear for storm organisation, an organised risk of severe weather is unlikely. A few heavy showers or thunderstorms may drift from France NW across parts of S England this evening and overnight too.

Issued by: Nick Finnis

Edited June 6, 2016 by Nick F

[William Grimsley]

Interesting! Some elevated cells that developed over Cornwall this morning are heading NW?

Even though it's cloudy here, looks like many places inland this morning are off to a sunny start which is a very good sign.

Not convinced on today's risk, interesting Nick has mentioned that thunderstorms will be more widespread today but BBC not even going for anything today? Looks like the NMM isn't showing anything either...

Just checked the NMM tomorrow, thunderstorms in this area! :O

Anyway, sky is loaded with Altocumulus cloud here this morning, I could chase but I may leave that till tomorrow, however BBC and NMM model both going for heavy showers/thunderstorms nearly overhead tomorrow so might not even have to move! Just looked at the Met Office forecast for tomorrow, looking very good for my area especially down towards the Totnes area with frequent torrential downpours with hail and frequent lightning, looking forward to that!

Edited June 6, 2016 by William Grimsley

[NO LONGER POSTING]

Like yesterday very sporadic showers again today, euro4 does want to 

10 minutes ago, William Grimsley said:

Interesting! Some elevated cells that developed over Cornwall this morning are heading NW?

Even though it's cloudy here, looks like many places inland this morning are off to a sunny start which is a very good sign.

Not convinced on today's risk, interesting Nick has mentioned that thunderstorms will be more widespread today but BBC not even going for anything today? Looks like the NMM isn't showing anything either...

Nicks forcast has highlighted in the West an areas that might catch a shower but very far and few between.

South East and Central, risk is more if anything gets imported later tonight EURO4 shows some stuff hitting the coast.

I personally can't see much popping off today, tomorrow is better! 

Hot spot for me would be today western coasts again but more so the further north you are

[Summer Sun]

Day 1 Convective Outlook

VALID 06:00 UTC Mon 06 Jun 2016 - 05:59 UTC Tue 07 Jun 2016

ISSUED 21:21 UTC Sun 05 Jun 2016

ISSUED BY: Chris

A similar synoptic set-up to the last few days will see weak ridging aloft from high pressure north of Scotland, however surface troughing over western Britain along with day-time heating and orographic lift should allow for scattered convection during the PM hours of Monday. As with the last few days, there continues to be uncertainty over the available moisture for isolated to scattered showers and thunderstorms to develop (air generally drier in the mid-levels). However, convection allowing models indicate Monday will be more active than Sunday, with widespread convection/thunder possible over NCen/NW Ireland. However, some pockets of more intense convection are also possible over S/SW Scotland. CAPE values of 500-800 j/kg are likely in the areas where models simulate showers, therefore they should be able to produce thunder given updraft strength. (Its worth noting that GFS seems to be over-doing surface moisture, thus CAPE, and showers have been much less widespread than it would be indicated the previous few days in that particular model). 

Given the slow moving nature of convection the biggest threat will be from highly localised flash flooding under the heaviest showers/thunderstorms. Virtually no wind shear is present, thus storms will be of the pulse variety and in most cases, as previously mentioned, aided by orographic uplift.

http://www.convectiveweather.co.uk/forecast.php?date=2016-06-06

[pad199207]

Sky looks very unstable already West of Dublin. Very sticky morning 19c

[Windblade]

The view from North West Bexley at 7am this morning. Can already see cumulus building.  Its pretty muggy here already with temps in the mid teens.

Edited June 6, 2016 by Windblade

[NO LONGER POSTING]

1 minute ago, Windblade said:

The view from North West Bexley at 7am this morning. Can already see cumulus building.  Its pretty muggy here already with temps in the mid teens.

Looks to me like crud, and ideally you want nothing kicking off yet, you will not get the heat required

[Ben Sainsbury]

I don't understand this community about how yesterday storms were very few and far between and yet everyone was saying "Oh tomorrow looks to be a lot better" and again today we see a lot of storm forecasts indicative of isolated storms and again people say, "Oh tomorrow showers seem to be more widespread". But to me it's annoying where people will say that the following day will be better for storms without valid evidence, almost like false hope, a recurring theme to me. Personally I don't see anything better about tomorrow whatsoever, setup pretty similar to today.

Edited June 6, 2016 by Ben Sainsbury

[Windblade]

43 minutes ago, Surrey said:

Looks to me like crud, and ideally you want nothing kicking off yet, you will not get the heat required

Hmm, I dunno, there was a lot of crud around at about 5am this morning but when that pic was taken at 7am that was clearing and I noticed some clouds behind which looked like cumulus. Difficult to see through the remains of the crud but I'm sure they were cumulus. Could be wrong though. 

Edited June 6, 2016 by Windblade

[Polar Maritime]

The BBC are certainly stressing a greater risk of convention in the West tomorrow than of today, So that should at least raise some hopes..

[weather09]

Who has said "..tomorrow looks to be a lot better", Ben? Not sure who you are referring to, but, speaking for myself, I don't do hope when trying to gauge likelihood of storms occurring.  I look at the data that's available to me and form an opinion.  Today does indeed look like it will have a little more in the way of showers and storms, despite the unfavourable pattern aloft, where good instability is situated over places of good elevation, and with defined sea-breeze and land CZs setting up to attempt to release this potential energy.  

If you don't see any difference in today's risk on yesterday's, or tomorrow's on today's, provide your reasoning as to why you think that is so.  

 

Edited June 6, 2016 by weather09

[MP-R]

The BBC seemed to show what looked like a 'convergence line' pattern of downpours developing SE-NW through Bristol later, but obviously they're TV forecasts can't be taken as gospel when predicting exact location of cells.

Indeed, tomorrow looks a lot better. Just hope cloud isn't an issue nearer the time.

[Ben Sainsbury]

2 minutes ago, weather09 said:

Who has said "..tomorrow looks to be a lot better", Ben? Not sure who you are referring to, but, speaking for myself, I don't do hope when trying to gauge likelihood of storms occurring.  I look at the data that's available to me and form an opinion.  Today does indeed look like it will have a little more in the way of showers and storms, despite the unfavourable pattern aloft, where good instability is situated over places of good elevation, and with defined sea-breeze and land CZs setting up to attempt to release this potential energy.  

If you don't see any difference in today's risk on yesterday's, or tomorrow's on today's, provide your reasoning as to why you think that is so.  

 

It's certainly not fair to say names, but in regards to differences in todays and tomorrows risk there isn't much to say. Defined convergence areas, high areas of instability, a trough sat to the west of the UK. Only difference I see is instability sat over more Central areas.

[Ben Sainsbury]

6 minutes ago, MP-R said:

The BBC seemed to show what looked like a 'convergence line' pattern of downpours developing SE-NW through Bristol later, but obviously they're TV forecasts can't be taken as gospel when predicting exact location of cells.

Indeed, tomorrow looks a lot better. Just hope cloud isn't an issue nearer the time.

That is exactly what some of the models are hinting at too. For Example: NetWx Model

 

Edited June 6, 2016 by Ben Sainsbury

[Chris.R]

 Already 21.3°C. Minimum last night was just 15.3°C, while the maximum yesterday was 28.0°C. Current trends would suggest that I could beat that today. 

 So I missed an electrified cell by 7 miles yesterday, knowing my luck it will be 3 miles today lol. At least I would be able to hear the thunder in that case. 

Edited June 6, 2016 by Chris.R