Convective Potential w/c Monday 17 October

[Andy Bown]

I hope the Mods don't mind me posting a new topic.

The local BBC forecaster Ian Fergusson this evening looked ahead to next week including Monday being an unsettled day with heavy showers, specifying the risk of hail and thunder.

[ZONE 51]

Yes the potential for thundery hail storms are coming in next week and through the week, extremely cold upper air at 500hpa, this gives the potential for hail which could be pretty potent in the heavier updrafts, places could see hill snow in the north ,but look out for the hail! never know that it could be giving a dusting in places, great! as this would look like snow..if you like that type of weather!

[Stormyking]

Yes the potential for thundery hail storms are coming in next week and through the week, extremely cold upper air at 500hpa, this gives the potential for hail which could be pretty potent in the heavier updrafts, places could see hill snow in the north ,but look out for the hail! never know that it could be giving a dusting in places, great! as this would look like snow..if you like that type of weather!

Of course I love that type of weather, I love hail especially when it is at its heaviest tends to be combined with Thunder and Lightning which is my ultimate favourite weather

[Coast]

A pretty low possibility for the places modelled above, maybe a chance into Tuesday and Wednesday but I'll reserve judgement until Monday morning.

[Nick F]

Quite an active cold front shifting SE tomorrow afternoon across central Britain reaching southern England around midnight. Netweather vertical velocity charts suggest some strong forcing/upward motion on the rear-side of this front - so despite lack of instability suggested by CAPE charts - we may see some shallow line convection develop along the back of the front as it moves SE across England and Wales tomorrow PM.

Strong wind sheer in the lowest km as front approaches with marked wind veer as front passes through, so an isolated tornado can't be ruled out if sufficient low-level instability can develop. Lightning wizard wind shear and significant tornado parameter chart highlights this potential:

Tornado potential rather uncertain, but there is also potential for damaging wind gusts too, convective gusts of up to 70mph indicated across Irish Sea coastal areas:

Colder northwesterly following front will favour blustery showers on Tuesday and Wednesday, these heavy and thundery with hail in the north and west, southern England probably escaping the heaviest showers.

[Coast]

The rest of the week looks pretty benign and settled according to GFS:

Maybe something this time next week down in the South, but a long way off and still very little:

[Richard McCarthy]

It's All Kicking Off In North Wales With Heavy Rain Just Kicked Off, Waiting For The Thunder Though.

[Richard McCarthy]

Today model's show that there are chances of Thunderstorms in a large areas of the UK, most of this is on the Northern parts of the British iles.

[dallas]

I see the Met office talking about some hail showers this afternoon in the S/E, anyone else see this potential?

[Coast]

I see the Met office talking about some hail showers this afternoon in the S/E, anyone else see this potential?

ESTOFEX have an area in The Channel, but not close enough inland:

UKASF have it summed up quite nicely:

Areas Affected:None.

Synopsis:A large area of low pressure will continue to edge away to the northeast over Scandinavia as a ridge of high pressure slowly builds across the British Isle from the southwest.

Discussion:Upper ridge will slowly build across Britain from the SW through the day. This will provide an increasingly stablising atmosphere over the British Isles.

A few sharp showers may be ongoing during the early morning hours (ELTs around -15 to -20C) before the ridging begins across coastal parts of N Ireland as well as NW England and N Wales

Otherwise, a weakening trough will move across E and SE England during the middle part of the day and this could produce a few showers. ELTs around -15C could trigger a odd sferic, but likely the greatest instablity will over the sea with SSTs around 14-15C (CAPE over the sea of around 200j/kg), therefore any thundery showers are likely to develop off the coast of East Anglia in the North Sea, or perhaps eastern parts of the English Channel.

Here's where that CAPE seems to be during this afternoon, I did see some convective cloud out over The Channel first thing this morning but it seems to have mostly moved Eastwards:

All seems just a bit too far East of us in the SE:

Today model's show that there are chances of Thunderstorms in a large areas of the UK, most of this is on the Northern parts of the British iles.

Can you reference them, because I can't find anything like that? (in fact quite the opposite!)

[Richard McCarthy]

There is a chance of convection due to Thunderstorm chances, That's why i am saying that the model's show today.

[dallas]

Thanks Coast, thew radar concurs..... currently

[A.J]

Cheshire Gap streamer in effect today...Plenty of heavy showers now starting to filter down the Cheshire Gap, providing some nice cloudscapes to my northwest...Could well be quite a wet afternoon for my area

[chionomaniac]

Travelling on the train to Liverpool. The Cheshire gap lake effect showers could be seen at a distance and have really pepped up passing Crewe. I think it is just rain but travelling too fast to notice!

[Nick F]

ESTOFEX have an area in The Channel, but not close enough inland:

Can you reference them, because I can't find anything like that? (in fact quite the opposite!)

Trouble is, if you just use GFS and especially Estofex, you may sometimes miss potential!

Showers across NW England and Wales may produce some thunder and lightning later this morning and into the afternoon, certainly will be some hail I should think. These showers are suggested by UKMO to develop more widely across The Midlands, East Anglia and SE England this afternoon, though look to be more well scattered and perhaps less heavy and thundery than further west.

[Coast]

Trouble is, if you just use GFS and Estofex, you may sometimes miss potential!

True, I need more favourites saved!

[Backtrack]

Mum suggests marble sized hail during the night set off car alarms, shop alarms and she was worried about the windscreen.

This happened twice, 4:30am and 6:00am.

[Richard McCarthy]

Chances of storms are 50/50 today

[Carl46Wrexham]

We've been getting clattered by shower after shower from the Cheshire Gap streamer here all morning. Cold with it as well. In car thermometer was reading 5c at 11am. Shame it's not December/January, as we do very well snow wise from these streamers.

[Arnie Pie]

Rain just arriving in Birmingham courtesy of the streamer from Cheshire

Hopefully some nice rainbows to catch later this afternoon (and maybe more )

8c

[dallas]

This weather approaching the S/E, any rececnt reports of hail? anyone been under it? please

[sunny scunny]

A heavy hail shower has just passed through here.

[dallas]

Cheers Scunny

[Costa Del Fal]

Almost all showers doding us or breaking up before they arrive thus we have a pleasant sunny afternoon here.

[weatherobsuk]

A good display of mammatus on the backedge of the old cell moving out the Peak District 30 mins ago. I managed to get a couple of images but it was quick moving and already out of sight now moving through Stoke & Derby as a convective line.