Convective / Storm Discussion Thread - 31st May 2017 onwards

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Sun 04 Jun 2017 - 05:59 UTC Mon 05 Jun 2017

ISSUED 23:13 UTC Sat 03 Jun 2017

ISSUED BY: Dan

... DAYTIME ...

Broad upper trough over northern Britain on Sunday will slowly exit to the NE as transient upper ridging develops ahead of more pronounced trough overnight and into Monday. Cool mid-levels atop SSTs/diurnal heating inland will produce another day of widespread showers across northern areas in particular, but also more showers are likely across southern Britain compared with Saturday as an instant-occlusion type feature migrates eastwards. Instability will be sufficient for occasional / sporadic lightning virtually anywhere, but the best environment (where lapse rates are steepest, CAPE highest combined with some late-day increase in DLS) will be found across northern and eastern Scotland - hence a SLGT issued here. Hail 1.5-2.0cm will be possible with this activity, perhaps also a funnel or weak tornado.

... OVERNIGHT ...

Overnight a deepening surface low will approach from the Atlantic, its associated fronts bringing rain to Ireland then western Britain. In a strongly sheared environment, the cold front will likely exhibit elements of line convection, particularly over southern Ireland. The depth of convection will be limited somewhat, and given marginal instability it is questionable as to how much lightning activity there will be (if any) - but this region will be monitored for a potential upgrade to SLGT. Conditions will be favourable for squally winds / rain and perhaps a tornado with any bowing segments. Some concern also over rainfall totals given likely training over similar areas as cold front becomes parallel to flow - but exact positioning is subject to some error, and may well be offshore where the greatest rainfall totals occur.

http://convectiveweather.co.uk/forecast.php?date=2017-06-04

[Arnie Pie]

Heavier cell just brushing past the W of Birmingham

......Feeding from the crumbs off Mother natures table i know

[OddSpot]

With nothing happening on our shores at present, Turin is taking a bit of a hit

http://www.skylinewebcams.com/en/webcam/italia/piemonte/torino/alpi-graie.html

http://www.skylinewebcams.com/en/webcam/italia/piemonte/torino/aeroporto-aeritalia.html

 

Edited June 4, 2017 by OddSpot

[Chris.R]

 Looks to me like there might be some potential tomorrow in the rain maybe?

Edited June 4, 2017 by Chris.R

[Frosty hollows]

47 minutes ago, OddSpot said:

With nothing happening on our shores at present, Turin is taking a bit of a hit

http://www.skylinewebcams.com/en/webcam/italia/piemonte/torino/alpi-graie.html

http://www.skylinewebcams.com/en/webcam/italia/piemonte/torino/aeroporto-aeritalia.html

 

Some amazing images on twitter from storms in Poland and SE Spain

[Frosty hollows]

Storm in Poland from eustorm Twitter feed

[OddSpot]

13 minutes ago, Frosty hollows said:

Some amazing images on twitter from storms in Poland and SE Spain

Some nice storms down between the Balearics and the Mainland at the moment

https://livecam-pro.com/en/majorca-port-pollensa.html

[Frosty hollows]

[Summer Sun]

Day 1 Convective Outlook

VALID 06:00 UTC Mon 05 Jun 2017 - 05:59 UTC Tue 06 Jun 2017

ISSUED 04:05 UTC Mon 05 Jun 2017

ISSUED BY: Dan

Sharpening upper trough will pivot slowly NE-wards across the British Isles on Monday - at the surface, a complex frontal structure with a multi-centred area of low pressure will gradually push erratically northwards and eastwards. 

The broad themes are...

some embedded isolated lightning may be possible over Wales/SW England later in the afternoon, perhaps extending to S England in the evening hours.

slack pressure pattern with areas of low-level convergence will bring the opportunity for scattered showers over Scotland and Ireland/Northern Ireland, with perhaps enough instability for some sporadic / isolated lightning. Here, a few funnel clouds or weak tornadoes are possible.

steepening lapse rates overnight as CAA takes place to the rear of the upper trough will increase the potential for lightning in showers over western Ireland.

http://www.convectiveweather.co.uk/forecast.php?date=2017-06-05

[Martin Auld]

Wow out of nowhere there is a thundery shower heading my way. Finally

 

 

Edited June 5, 2017 by Martin Auld
Rearranging

[Martin Auld]

Nope.... hold on I think it died before it reached me. Not surprised to be honest

[Martin Auld]

Wait it activated again as it's gone over I'm officially out of the no storms club now. Apologies for spamming this is literally all the action I've had this year

[carl1980]

16 hours ago, OddSpot said:

Some nice storms down between the Balearics and the Mainland at the moment

https://livecam-pro.com/en/majorca-port-pollensa.html

In benidorm at the moment, lots of lightening yesterday evening 

[Flash bang flash bang etc]

Gotta love accuweather - promising me 6 thunderstorms before the end of August ...

[Mapantz]

24 minutes ago, Flash bang flash bang etc said:

Gotta love accuweather - promising me 6 thunderstorms before the end of August ...

For a specific location, or the whole of the UK? lol

[Mokidugway]

1 minute ago, Mapantz said:

For a specific location, or the whole of the UK? lol

Here's their specific location 

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Tue 06 Jun 2017 - 05:59 UTC Wed 07 Jun 2017

ISSUED 20:22 UTC Mon 05 Jun 2017

ISSUED BY: Dan

Over the past 12 hours, NWP guidance has trended towards a slower clearance of the wrap-around frontal system over eastern Britain - consequently the window for deep convection is a little narrower, and if this trend continues then it is likely some northern portions of the large LOW threat may need to be trimmed back farther south. 

Nonetheless, on the rear-side of the upper trough (-turn cut-off low), cold mid/upper levels will advect SE-wards across the LOW threat area, steepening lapse rates and generating a few hundred Jkg-1 CAPE in response to SSTs and diurnal heating inland. Provided cloud clears NE-wards to allow sufficient insolation, numerous scattered showers are forecast to develop, perhaps weakly-electrified. Better shear will be present towards the SW, perhaps enabling some better organisation but given limited instability no SLGT will be issued for now since lightning is not expected to be widespread and / or frequent enough to upgrade to >30% probs. 

On the east coast, depending on how far inland the wrap-around rain shield extends there may be scope for some frictional convergence to develop on the inner portion of this front - hence some embedded convection may develop in an environment with marginal instability. A small LOW threat has therefore been issued, although subject to positional errors and unlikely to result in much, if any, lightning.

http://www.convectiveweather.co.uk/forecast.php?date=2017-06-06

[k66yla]

Plenty of thunder here but no lightning. Seagulls were going nuts for a couple of minutes but have now calmed down.

[Thunderstruck]

13 minutes ago, k66yla said:

Plenty of thunder here but no lightning. Seagulls were going nuts for a couple of minutes but have now calmed down.

Are you sure it's thunder and not just the strong winds? Nothing showing up on lightning detectors, and I don't think the SE was forecast thunder for tonight.

Please correct me if I'm wrong  

[Allseasons-Si]

33 minutes ago, k66yla said:

Plenty of thunder here but no lightning. Seagulls were going nuts for a couple of minutes but have now calmed down.

There is nothing showing of ppn intensity nor any activity in your area to classify that there is a storm,could it be sonic booms from jets?

 

[k66yla]

It was definitely thunder and it happened more than once. It sent the seagulls crazy for a minute.

[samadamsuk]

Shear looks pretty good for the SW tomorrow, fingers crossed!

Samos

[Flash bang flash bang etc]

18 hours ago, Mokidugway said:

Here's their specific location 

That's about right lol. No it was specific to Godalming - their FI engine is a bit nuts.

[Weather-history]

 

[A.J]

yay, thunder and lightning here.....with rather large hail!