Uk Convective General Discussion & Forecasts - April 2012 part 3

[Aaron]

Yes, and that's why I am moaning 'incessantly' because most people are doing okay except myself and a few others! Not even a hail shower here, or even a torrential downpour.

Of course in these set ups some people will miss out completely, but we all hope that we aren't one of 'those' people that misses out completely.. right? I just dream of a Spanish plume where hopefully everyone will see something...

If you were in my position you'd understand, mark my words!!!!!

Edited April 22, 2012 by Aaron

[chionomaniac]

Wasn't much here today, just a few moderate showers blowing around.

Another mediocre convective day tomorrow under a continuing poor atmospheric profile for something more substantial, with infrequent lightning and possibly marble-sized hail again the likely entertaining features of any storms. Slack converging of the surface winds, steep lapse rates and still relatively low LCLs brings another small of funnel development.

I await a major pattern change that favours strong/severe thunderstorm development.

And what do expect living in England in mid April?......

Perhaps you should move to the plains in America!!!

[Chris.R]

Some sharp showers around atm, hopefully it's my day to see something.

[NO LONGER POSTING]

Once again good luck everybody today! Lets hope that today is a little better than yesterday...People that are getting frustrated don't worry! This is only April! We have the whole of summer yet when we can really get some "proper" thunderstroms...All good things come to those that wait...Out of this whole thundery period I have heard about 10 rumbles seen 2 flashes of lighting and only had 1 good proper "storm"..Okay better than some..But others have had numerous t-storms over this period...

[Liam J]

Heavy showers here this morning in Northumberland, thoroughly wet ATM but looking brighter to the north.

Decent cape and lift values so lots of potential today for further heavy downpours and thunderstorms to develop quite widely. Good luck everyone, let the fun and games commence

[Supacell]

Some great pictures on here, i long for the day when I catch a storm again. Well done to the photographers

No chase for me again today, unless storms can hold on into the evening. Given the last several days I think that is unlikely. I agree this April has been fantastic for storms, but only for some people. I, like Aaron and Weather09, have not seen anything from these last 2 weeks.

Its unusual though for me to see much in April so to see anything before month end would be a bonus, can't help to feel a little frustrated though.

[robt]

Looks like Newcastle is about to get another soaking - it is very dark to my W and NW, and there is even a poorly formed roll cloud to the NW. Hopefully some thunder this time, and a bit more hail, but I'm not that fussy

Was up at Hartside for a little while yesterday, then came down through Hexham and Corbridge. There were some quite impressive showers and cloud forms that I saw when we were going along, and the roll cloud that formed was a bit shoddy looking but it was definitely there.

Thought I'd got some footage of it, but the camera was looking the other direction at the time

[chionomaniac]

I don't really see what the time of year has to do with anything, Chiono. Much better thunderstorm setups can (and have) arise in April...just need to get that ideal setup. There's little low level moisture; no vertical wind shear; modest instability... it's a poor setup regardless of which country I'm in.

No. A poor set up would have no storm potential at all. So it is certainly better than that. I guess that I am far more easily pleased.

[Evening thunder]

One of the best thunderstorms I've seen occurred in a cold air mass at the end of October 2008 (and I remember a good one in mid-winter as a young child).. just saying.

I'm happy with an April packed full of thundery showers and skies, before hopefully (he says) some warmer air-mass thundery set-ups arise closer to and during summer.

The showery stuff coming into the SW at the moment looks like non-thundery showery rain though.

[Aaron]

Some lightning detected around Manchester. Heavy shower moving over Bradford, not electrical.

[TonyH]

Don't be greedy for this time of year most of us aren't doing to badly

True this has been 'April showers' exemplified this year. OK so not all of us have had thunder but some wonderful cloudscapes and radar returns, along with the thrill of 'will it or won't it' die out/ hit me!

[Liam J]

Activity kicking off over the southern parts of NW England, thundery showers developing around the Manchester area.

Those showers over Bradford look like they'll be knocking on the door of Leeds shortly Aaron, perhaps passing to the south?

Edited April 22, 2012 by Liam J

[Carl46Wrexham]

Don't be greedy for this time of year most of us aren't doing to badly

Yep...but please keep in mind that yours truly and quite a few others in here are scratching our heads wondering what all the fuss is about - having seen nothing to date.

[Alex95]

Places near the coast in the NE might not see as much convection today due to the position of the low, but it is already looking very black to the west of Newcastle.

[Harry]

Activity kicking off over the southern parts of NW England, thundery showers developing around the Manchester area.

Those showers over Bradford look like they'll be knocking on the door of Leeds shortly Aaron, perhaps passing to the south?

That confused the life out of me...southern parts of NW England, lol!

Sufficed to say I'm glad to see southern areas bagging the glory again

[Supacell]

Some lightning detected around Manchester. Heavy shower moving over Bradford, not electrical.

There was some small hail but nothing much more than that. Sun is out now.

[johnholmes]

No Watnall ascent this morning, the current radar shows winds from 5000 up to 18000ft backing with height-an indication of colder air moving in aloft.

The 00z Extra Doncaster skew-t and its forecast out to 18Z show fairly marked instability with anticipated T and Td values through the day. Tops fairly readily to about 26000-28000ft although possibly a bit less by evening.

relevant ascent and notes below-it should be a reasonable indicator for much of central and eastern England

Edited April 22, 2012 by johnholmes

[Liam J]

That confused the life out of me...southern parts of NW England, lol!

Sufficed to say I'm glad to see southern areas bagging the glory again

Lol well NW England covers a large area, I class the southern areas as Liverpool, Machester and Cheshire etc. I'm in the northern part of the NW region up in Cumbria.

Edited April 22, 2012 by Liam J

[Alex95]

Extremely black cloud to my west and north now - the anvil has reached me now.

[I Cumbria Marra I]

Liam, what are our chances today?

[legritter]

looks like another good week or so coming up gang ,and perhaps later this week ,next week we could see some storms moving north from south . there is still the possibility of some localised high rainfall totals . iv noticed more and more these days that we seem to get a run of similar synoptics for a long time .which is good for us storm addics ,who have been starved for a long time .wonder what the summer time synoptcs will be , hopefully spanish plume ,spanish plume mixed with one or two cooler days each week , bring it on ,cheers legritter .

[Chris.R]

Some heavy showers here now, that last one was fairly torrential. Looks like a small change in wind direction is making all the difference for here. Interestingly, I would class my location as central north west england, I think of southern NW england as cheshire and soutth Liverpool.

Lets see some storms. I wunder if a convergance zone is setting up!?

[Coast]

The Eastbourne storm shield has been fully operational this weekend and most of last week with only an occasional shower to show for all this potential!!!

Still a few more days of possibilities and this afternoon is again looking good for some:

ESTOFEX have another watch in the SE:

Storm Forecast

Valid: Sun 22 Apr 2012 06:00 to Mon 23 Apr 2012 06:00 UTC

Issued: Sat 21 Apr 2012 23:25

Forecaster: SCHLENCZEK

A level 1 was issued for N Algeria and Tunisia mainly for large hail.

SYNOPSIS / DISCUSSION

An upper trough is centered over the western, central and northern parts of Europe. In the vicinity of this system, diurnal heating of the boundary layer and upper level cooling lead to some hundred J/kg CAPE. Except for N Italy, deep layer shear is not worth to mention which will limit the severe weather threat. An isolated large hail / heavy precipitation event may occur but as none of the models show a clear focus for an enhanced hail chance, no threat level is issued.

It is still questionable whether thunderstorms are likely to form over N Italy or not. Deep layer shear is very strong (30 - 40 m/s) but the CAPE signal is very weak. Therefore, no threat level was introduced but an update might be possible.

UKASF:

Forecaster: Dan

Last Updated: 2012-04-21 22:35:00

Valid: 2012-04-22 00:00:00 - 2012-04-22 23:59:00

Areas Affected:

SLGT: S + W Scotland, N England, Midlands, E Anglia, CS England, N + E Wales, Northern Ireland, C + E Ireland

Synopsis:

A vertically-stacked broad area of low pressure will slowly fill over the North Sea during the day. Another day of widespread convection is likely, mostly focussed along local convergence boundaries.

Discussion:

With cold mid-levels (-31C at 500mb) atop rising LSTs in response to diurnal heating, ~600J/kg CAPE will develop allowing scattered showers and a few thunderstorms to form. The main focal point for such showers/storms will be in a zone from western Scotland, across Cumbria towards the north and east Midlands. ELTs locally down to -45C suggest convection will be deep enough for lightning to occur in stronger cells.

Weak shear will mean storms will be poorly organised and thus are unlikely to produce lightning for any great length of time, and it is for this reason that we primarily only go with a SLIGHT coverage level. Severe weather is unlikely, although given the convergence-induced convection, it is possible that a CZ-type funnel could form.

Hail is also likely in many of the showers, with a local event with diameter up to 2.0cm possible, particularly over Ireland where some 20kts DLS may allow convection to become a little more organised/longer-lived, and thus such updraft/downdraft separation may allow hail to remain in the cloud for longer, increasing hail size.

Convection and associated showers will typically decrease in coverage and intensity during the evening hours as daytime heating subsides.

Both missing out on my location, but hey!!!

General forecast has the same as the last few days:

21st OWS:

Nice big blob of red for lightning chances later around the East Midlands and above:

A bit of CAPE around toward the end of the afternoon:

I'm tempted to look to East Anglia, the East Midlands and areas just to the North and South of there today, but the radar will be the guide from lunchtime onwards. Nothing organised, but a few claps of thunder maybe and possibly some more hail?

[Liam J]

Liam, what are our chances today?

The potential is there for convective development but as has been the case over recent days Cumbria has been in a dry slot dodging most of the showers. I have a feeling this may repeat itself today. Central, southern and eastern areas of the country should do pretty well yet again.

Out of the last few days I'd say today has the most potential for our region.

Let's wait and see how the day pans out, radar watching yet again

Edited April 22, 2012 by Liam J

[A.J]

Two areas to note for the Midlands region.....NW Midlands & the South Midlands, LLC's in these areas will aid convection given diurnal heating heating...Hi-res models have been picking up on LLC's in these areas, and current wind patterns infer these are verifying.....I would expect some heavy showers/storms or more persistent heavy rain in these areas (Welsh borders through Staffs towards Leicester, and Hereford through Worcester towards Coventry as areas with good potential....and later on this afternoon I'd take at a stab at thundery showers breaking out along the A45 corridor