Uk Convective General Discussion & Forecasts - April 2012 Part 4

[Eskimo]

Interesting day of radar watching of course, I'll eat my own hat and the rest of my clothing if we get storms in the evening.

[Robbie Garrett]

Personally just having a look, and for what the weather forecasters have said on the Aviation website. It's just going to be heavy rain, so at least a chance to add another 10-15 maybe 20 mm or so more to the horizon.

How about, be prepared to be disappointed and you might get something but as far as I am aware it looks to me an occluded front providing very heavy rainfall.

[Harry]

Oh Robbie mate, is everything ok? This is not like you at all!! Normally the sniff of a chance and you'd be ramping

I agree, it will largely be an active occluded feature, however based on the latest info there is a risk of thundery showers/t-storms before the front establishes itself.

To be fair, my confidence level is circa 20% max! But I've got my fingers crossed

[Costa Del Fal]

GFS 18z less promising for tomorrow with just a small section of good instability in the SE and then the Midlands in the evening.

[Robbie Garrett]

Oh Robbie mate, is everything ok? This is not like you at all!! Normally the sniff of a chance and you'd be ramping

I agree, it will largely be an active occluded feature, however based on the latest info there is a risk of thundery showers/t-storms before the front establishes itself.

To be fair, my confidence level is circa 20% max! But I've got my fingers crossed

Noo, had a long weekend at work!! TIRED!!

I am really unsure about tomorrow night, I really think it will be a wet fart. I guess I can say the temperature being 19*C tomorrow gives me a tad confidence. Let's see, as there's nothing for development of CBs in the forecast or TSRA. I'll re-think tomorrow lunchtime or so

What lacks me confidence is the MetOffice are confident, but the fact is it lacks considerable uncertainty. Such low likelyhood really does not warrant a warning. What's up with these Warning systems these days, 40mm is not a lot of rain. I remember it raining for 7 days straight 3-4 years ago and not a warning in blimming sight.

Anyways, no point giving hope yet... Tuesday Mornings TAF catchment is likely to be released at 1100z

Edited April 29, 2012 by Robbie Garrett

[Coast]

21st OWS have areas of possible thunderstorms through today

and overnight in the 'interesting' period:

They haven't updated the ensemble lightning possibility for a few days so treat this one with caution:

Is anything going to be a bit too far away from us in the extreme SE corner tonight???

The Hi resolution HiRLAM charts have it over Kent and Sussex, GFS more to the East over Belgium and Holland:

Owwww that's very messy!

More damn rain!

But look at this purple area over the SE:

Gusty winds a possibility:

Well depending where you look at you're take on the charts, there could be some localised storms and plenty of rain in the early hours of the first day of May, lets see if it wakes me up!

[Coast]

Marginal for Eastbourne I think:

similar along the coast into Kent:

[Harry]

Those charts do look mouthwatering!!!

If we're unlucky in terms of electrical activity, we'll still get some lively downpours of rain!!!

Doesn't surprise me in the slightest that experienced and qualified forecasters are a bit

In any event, it's going to be an exciting evening radar and sky watching.

[Coast]

In any event, it's going to be an exciting evening radar and sky watching.

Going to be some bleary eyes tomorrow morning, I just hope there isn't any grumpiness if it doesn't come off!

[Harry]

Going to be some bleary eyes tomorrow morning, I just hope there isn't any grumpiness if it doesn't come off!

Naah! I think people (including myself) are realistic to the potential for this evening....what almost certainly will make people grumpy is the rash of sferics as the mass of heavy rain/storms sweeps towards our shores, then at around midnight when the sferics disappear and we just get a deluge of boring rain... it's on the cards is it not!!

[staplehurst]

Naah! I think people (including myself) are realistic to the potential for this evening....what almost certainly will make people grumpy is the rash of sferics as the mass of heavy rain/storms sweeps towards our shores, then at around midnight when the sferics disappear and we just get a deluge of boring rain... it's on the cards is it not!!

Couldn't agree more! It's happened so many times in the past it's become tradition!

Edited April 30, 2012 by staplehurst

[Coast]

Tough call this one and Dan, your UKASF forecast seems on the money so far, are you looking to update later today?

MetO still have a warning in place:

London & South East England

Rain

Issued at: 1148 on Sun 29 Apr 2012

Valid from: 0000 on Tue 1 May 2012

Valid to: 2359 on Tue 1 May 2012

Outbreaks of rain, heavy and possibly thundery, are likely to affect southern England and the southern half of Wales, on Tuesday.

The public should be aware that, following recent heavy rainfall, further localised flooding is possible, as well as difficult driving conditions. In addition strong easterly winds are likely across the Midlands and parts of Wales.

[staplehurst]

Tough call this one and Dan, your UKASF forecast seems on the money so far, are you looking to update later today?

MetO still have a warning in place:

Possibly, but for the time being I think it's OK. But as you say really tough, especially when factoring in just how many times we have seen similar setups disappoint.

I'm in Norwich at the moment, and based on that fact alone with my storm shield up here with me, you guys down south should be getting a spectacular display tonight

Edited April 30, 2012 by staplehurst

[Robbie Garrett]

I am still not convinced by tonight, I will however radar watch till a certain time and see what all the fuss is about. Nothing for tonight's TAF's for any TS or CB activity. Only +RA (Heavy Rain)

[Chris K]

Well good luck to those in the SE/S coast. If this does happen, by the time the rain reaches here I think any electrical activity will be non-existent by then.

If I didn't have to be up early tomorrow it'd be a night of interesting radar watching at least to see how/if things develop!

Edited April 30, 2012 by Bugganuts

[Coast]

Just had a trawl through the NW Extra NMM charts for midnight and there is quite a bit of MLCAPE about and the MLCIN seems to be offshore more towards France. I'm getting that little itch about this one (no, not that kind of itch!!) and it has the right feel to it, just don't want to go to bed all excited and find I wake up in the morning without having had my favourite kind of storm which is a middle of the night rumbler!

[Harry]

Just had a trawl through the NW Extra NMM charts for midnight and there is quite a bit of MLCAPE about and the MLCIN seems to be offshore more towards France. I'm getting that little itch about this one (no, not that kind of itch!!) and it has the right feel to it, just don't want to go to bed all excited and find I wake up in the morning without having had my favourite kind of storm which is a middle of the night rumbler!

Indeed!! That's my feeling too...it's one of those horrendously complex setups, butthere is a part of me which is unduly optimistic!!

Had a look at the national and regional beeb forecasts and the 't' word is noticeably absent! However, the graphics indicating far heavier rain than their graphics were last night - also, rather interesting, is that yellow/green blobs are clustered, suggesting custered downpours along the front, rather than a large frontal swathe!

[snow raven]

Just watched the local ITV weather report, and the forecaster spoke about heavy thundery storms moving up from France arriving in the SE over night...

[Harry]

Just watched the local ITV weather report, and the forecaster spoke about heavy thundery storms moving up from France arriving in the SE over night...

I like the sound of that!! (just a bit of harmless ramp on my part)

The latest FAX chart throws a further bit of interest into the mix...far from being a just a frontal affair, the FAX chart progs a trough feature to whip through ahead of the main frontal mass. This is potentially significant, particularly in respect of MLCAPE progged on the NMM charts.

The met experts are frustratingly silent on this atm lol...in the immortal words of Delia..."let's be 'avin you!!"

[Sprites]

Heavy thundery storms, or storms without thunder? hmm , i do hear some odd weather terms on our Local forecast sometimes, like showers with thunder, and perhaps some lightning too LOL, i think the most vague term is thundery rain, which usually means showery heavy rain, but without thunder..would be easier if they just said thunderstorms!.

[Robbie Garrett]

So a chance of an MCS tonight Harry?? Are your planning on going down to the Coast??

[Coast]

Are your planning on going down to the Coast??

He's not sharing a bed with me!!!!!!

[legritter]

HELP ,CUSTERED DOWNPOURS HEADING FROM FRANCE ,HARRY from kent forecasts heavy falls of custard with the odd rumble of crumble .im not taking the P... as i can remember my mistake a couple of years back , a trap around ofclusion . certainly looking very interesting for later tonight , but still a bit to early to call if a thundery affair or just heavy thundery rain .will be interesting to see whats developed by 8pm this evening over france .id say about 50/50 for some descent storms ,regards legritter

[Robbie Garrett]

He's not sharing a bed with me!!!!!!

I just Lol'd my house down!!

The latest from the MetOffice aviation site.

Outlook valid until 01st 0600z - Thundery Airmass pushing north east across Southern UK, stregnthening easterly airflow across the UK, low cloud in the north east. Areas E1 (South wales, South west England and South East England ) Isolations of Ocassional on the Continent of ocassional 7km visbility in showers of Rain with Isolations of 3000meters in heavy showers of rain with heavy thunderstorm in rain. Moderate turbulence, with isolations of severe turbulence in the far east from 18z, isolations of hill fog. Areas SCT with BKN AC clouds, 08000ft. SCT broken CU and SC with severe icing at 01500ft-04000ft/07000ft-XXX ISOLATIONS of CB01500ft-03000ft/XXX E1

Edited April 30, 2012 by Robbie Garrett

[Harry]

I think Estofex largely have it right today when they say.

Thanks Brickfielder as ever very helpful

Just a case now of radar/satellite watching to see if this complex setup can surprise us a little.