UK convective general discussion and forecasts

[Harry]

Not entirely sure whats occurring around the SE of England, but this is not the first time erroneous sferics have been picked up...unless of course weak strataform cloud is producing sparks

[Coast]

Where are you getting them Harry - I can't see anything currently?

[Lauren]

As long as it's not stormy on Saturday 6th. That's when our annual family BBQ is.

[Costa Del Fal]

Wasnt it August 6th that has been popular with storms in recent years, (Seriously Lauren!)? :lol:

[Harry]

Where are you getting them Harry - I can't see anything currently?

The NW lightning detector (strikestar??) - unless it's pi*$ed lol

It's detected a small cluster of them now

Edited July 27, 2011 by Harry

[Coast]

Wasnt it August 6th that has been popular with storms in recent years, (Seriously Lauren!)? :lol:

Yep, had a nice one here in 2008:

The NW lightning detector (strikestar??) - unless it's pi*$ed lol

It's detected a small cluster of them now

Hmmm, anaprop or Chinese lanterns! :lol: I still can't see it - have you cleaned your glasses?

[Harry]

Yep, had a nice one here in 2008:

Hmmm, anaprop or Chinese lanterns! :lol: I still can't see it - have you cleaned your glasses?

Look - surely it cant be me?

Here's the evidence!

[Weather Wizard]

I know it's not much but estofex have some of us in their lowest (thin yellow) warning zone tomorrow.

Maybe???

[ZONE 51]

I know it's not much but estofex have some of us in there lowest (thin yellow) warning zone tomorrow.

Maybe???

i know not much sign either, but lined for a reason, and thats because there is some activity around, some fronts are crossing the West now with heavy rains and these heading towards the southeast arriving as an occluded front as far as i know? i think with no CAPE we could think 100% nothing, but we have through thursday some slightly unstable air around, heat in the South especially SE and dew points quite high, so feeling muggy and humid? so im thinking with these fronts some rumbles of thunder? im sure some activity for the Southeast if that front comes in a battle with the opposite airmass, im not sur on this but a low risk maybe to be had . if my info is not all correct please do say!

[Coast]

Can't see anything I'm afraid.

UKASF put it quite well:

Forecaster: Matt

Last Updated: 18:59 Wednesday, 27th July 2011

Valid: 00:00 Thursday, 28th July 2011 - 23:59 Thursday, 28th July 2011

Areas Affected: None

Synopsis:

A marked ridge is evident within the mid and upper levels of the atmosphere across the UK with resultant warm mid-level temperatures (500mb temps near -15C). A large area of high pressure (1033mb) is evident to the west of the UK, as a weak northerly air mass dominates across the UK during the day. A weak and slow moving frontal zone is expected across Scotland to the Isle of Man, to west Wales and Cornwall near 1200Z with resultant frontal cloud and mainly light precipitation.

Discussion:

The synoptic situation is once again leading to another day in which convective activity is unlikely, particularly on any significant level with little or no threat of thunderstorm activity. Some forecast soundings are signalling some instability across the south-east of England during the afternoon, which may well lead to some isolated mainly light or moderate showers, but again convective activity is expected to be limited and very few, if any of the available forecast models, signal a threat of showers in the south-east.

The frontal zone running down through the UK is expected to bring more extensive cloud to many western and northern areas than compared with recent days and given that the frontal zone is undergoing frontolysis, the precipitation associated with the fronts is likely to be mainly light or moderate in intensity with rain and drizzle possible. Clearing conditions are expected to the west of the fronts across Ireland as the day progresses

Next Wednesday and Thursday still my point of interest currently:

[Harry]

i know not much sign either, but lined for a reason, and thats because there is some activity around, some fronts are crossing the West now with heavy rains and these heading towards the southeast arriving as an occluded front as far as i know? i think with no CAPE we could think 100% nothing, but we have through thursday some slightly unstable air around, heat in the South especially SE and dew points quite high, so feeling muggy and humid? so im thinking with these fronts some rumbles of thunder? im sure some activity for the Southeast if that front comes in a battle with the opposite airmass, im not sur on this but a low risk maybe to be had . if my info is not all correct please do say!

Have to say, I noticed first thing the humid feel...not exactly unbearable but it is definitely muggier than of late.

[Coast]

Have to say, I noticed first thing the humid feel...not exactly unbearable but it is definitely muggier than of late.

Dewpoints and humidity are certainly up, but there's nothing to cause a spark

[Lauren]

Wasnt it August 6th that has been popular with storms in recent years, (Seriously Lauren!)? :lol:

Oh man. Our family BBQ's are epic.

[paul m]

Way too humid today. Even the kids dont feel like doing anything. I does not help with everyone having a rather nasty cold

[Harry]

Way too humid today. Even the kids dont feel like doing anything. I does not help with everyone having a rather nasty cold

Nah it's lovely! Love it humid

[paul m]

Where the heck did the rain come from. Nice heavy shower here

[Jane Louise]

Heads up for tomorrow! Not sure whether it's worth starting a new thread though.

A chance of heavy showers for some in the south:

Moderate Risk of Heavy Showers - Southern England - Friday 29, July 2011

General Theme

Warm moist stagnant airmass covers much of Southern England, A weak front is lying across N England, Wales and SW England having weakened in the face of building pressure. A SE'ward moving upper trough will sink SE on Friday and will provide just enough impetus combined with some slack flow (and assoc convergence) across SOuthern England on Friday afternoon and evening.

HIRLAM, GFS (though 12Z less keen) and NAE break out showers from the Chilterns S'ward. Esp across SW London, across towards Salisbury Plain and west towards SOmerset. There is some difference in Opinion on Heaviest amounts. GFS has recently favoured CS and SW England vs the NAE which has heaviest totals SW of London.

Many places will be dry and will escape the showers but some of the developing showers could be quite sharp with locally heavy downpours. A very few locations will be at risk of some isolated heavy downpours. Thunder seems unlikely.

http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=44172

[Bluebreezer54]

Its certainly worth a heads up Jane !!

[davehsug]

I was surprised a few isolated showers didn't get going today. There was some pretty impressive convection here around lunchtime today. It was killed off by the approaching front, but I expected something further east after seeing that.

[ZONE 51]

GFS 18z showing the best potential in Central Southern and Sw england, with some unstable air best in these areas shown on the CAPE/Lifted index charts, the heaviest precipitation indicated by GFS 18z in these areas, also a convergence zone developing-see yellow line on wind chart.

on the other end of scale NAE 18z expects the heaviest ppn breaking out in the SE. GFS and NAE show quite high dew points and temps in the 20-23c zone for the South, so a warm and humid feel to things i think.

we need to wait for the updates later.

GFS 18Z

-CAPE/LI

-surface wind/convergence line

-dew points

-ppn - 1500hrs

-ppn - 1800hrs

-surface wind - 1800hrs

-surface temperatures - 1500hrs

- storm risk at 1800hrs

NAE 18z

-NAE-ppn 1500hrs-2100hrs

-NAE-ppn-1800 - 0000hrs

The potential is there for some interesting weather, if we mix the NAE+GFS then its the whole South at risk we would know by the afternoon when they develop..

-

Edited July 29, 2011 by ElectricSnowStorm

[Coast]

I'm afraid it's another day without action from where I sit!

Again UKASF have it covered nicely:

Synopsis:

A well established area of high pressure (1027mb) centered just to the west of Scotland during Friday is forecast to be the dominant synoptic feature of the weather through the day. A marked upper ridge is also evident in association with this surface anticyclone along with warm mid and upper level temps (500mb temps near -15C). There is currently forecast to be a frontolysing occlusion across parts of the south during the day, but this is likely to become more of a trough-type feature. Generally a stable and light north or north-easterly air mass is expected across the country, this light and variable in the west.

Discussion:

The continued quiet period of weather in terms of convective activity is forecast to continue throughout Friday as well. Pressure is forecast to continue to build across the UK during the day with many areas experiencing pressure of at least 1024mb, but locally higher further west. The marked upper level ridge is forecast to create a well established subsidence inversion across the UK and whilst some low level convection may occur beneath this inversion, there is no risk of any significant convective activty and/or thunderstorm activity.

The frontolysing occlusion/trough which was highlighted within the synopsis across southern England may well aid to create a more unstable atmosphere, but only up to near 10,000ft at very most, given forecast soundings. This feature may well act to create some instability which could well lead to a scattering of mainly light or moderate showers and with perhaps a very isolated heavy shower. However, given the broader synoptic pattern, there still remains little or no threat of any major convection and/or thunderstorm activity through Friday across the UK.

Some CAPE late in the day to the West:

But little else:

Except maybe some rain:

Still concentrating on Wednesday onwards:

Next Friday into Saturday looks really interesting!!!

[Harry]

Next Friday into Saturday looks really interesting!!!

Is that the 6th August by any chance Coast?

[Coast]

Is that the 6th August by any chance Coast?

OMG yes, the dreaded 6th August or 'Storm Saturday' as we like to call it around here! :lol:

[Stuart]

6 days from now look great for me but still long way off yet :drinks:

[Harry]

The GFS 06z is pornographic almost...screams potential for night time storms at the moment, which will be my first of 2011 if it comes off