Storm & Convective Discussion - 7th August Onwards

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Fri 12 Oct 2018 - 05:59 UTC Sat 13 Oct 2018

ISSUED 20:08 UTC Thu 11 Oct 2018

ISSUED BY: Dan

As a deep low runs northwards to the west of the British Isles, a short window exists during Friday morning of marginal CAPE and very strong shear, which will allow some heavy, squally showers to affect parts of NW Republic of Ireland to W Scotland - with some sporadic lightning possible (but coverage probably not high enough to warrant a SLGT).

 

By this stage, a moist conveyor will become established across western Britain, with persistent orographic rainfall. On the eastern flank, elements of mid-level instability release will be possible, especially during the early hours of Saturday. Forecast profiles look rather saturated, which coupled with marginal instability will limit buoyancy - but given the strongly sheared environment, a few sporadic lightning strikes may be possible over SW England and S Wales during this period.

http://www.convectiveweather.co.uk/forecast.php?date=2018-10-12

[Summer Sun]

Day 1 Convective Outlook

VALID 06:00 UTC Sat 13 Oct 2018 - 05:59 UTC Sun 14 Oct 2018

ISSUED 08:24 UTC Sat 13 Oct 2018

ISSUED BY: Dan

A couple of pulses of mid-level convection will affect the LOW threat area during Saturday - particularly during the morning hours, and then again the early hours of Sunday. Limited instability suggests lightning activity is unlikely to be widespread, if any at all (better chance perhaps towards Sunday morning during the latter stage of this forecast period).

http://www.convectiveweather.co.uk/forecast.php?date=2018-10-13

[Summer Sun]

Day 1 Convective Outlook

VALID 06:00 UTC Sun 14 Oct 2018 - 05:59 UTC Mon 15 Oct 2018

ISSUED 08:48 UTC Sun 14 Oct 2018

ISSUED BY: Dan

Frontal zone will linger across England for much of this forecast period, with various pulses of heavy precipitation running northeastwards along the front at times. On the eastern flank, elements of embedded mid-level convection will bring the risk of some isolated / sporadic lightning.

 

During the evening and night hours, the flow begins to buckle and back more to the SE, increasing the WAA from the nearby Continent. This will tend to push the frontal zone back to the west a little, while also encouraging better mid-level instability release over the English Channel, with the chance of some elevated thunderstorms developing here and then running NNE-wards across SE England and East Anglia.

 

Some uncertainty exists both over the available instability (profiles are rather saturated which will limit buoyancy and reduce lightning potential) and also over the exact location of where thunderstorms may occur which will be heavily dependent on the shape of the surface low and position of the frontal zone. In reality, there will probably be a few heavy showers with limited lightning activity. For now, a low-end SLGT has been introduced where the best multi-model consensus exists, but this may need to be shifted adjusted depending on trends later today.

 

http://www.convectiveweather.co.uk/forecast.php?date=2018-10-14

[Another Kent clipper]

Thanks SS.  Ooh, hello.  The channel rain is starting to get going.  Thunder o'clock soon londoners

 

 

[East_England_Stormchaser91]

8 minutes ago, Another Kent clipper said:

Thanks SS.  Ooh, hello.  The channel rain is starting to get going.  Thunder o'clock soon londoners

 

 

Yes, tonight may well be a last ditch effort for some thunder, and probably the last potential plume event as 2018 draws to a close. Of course, not ruling out any beefy showers as we head further through autumn particularly in coastal areas with still relatively warm SST’s. 

Keeping my eye on that cluster of heavy showers with a few sferics heading up the channel. 

[NO LONGER POSTING]

Could be quite torrential in places already around Brighton area.. Keep us posted if anyone sees lightning! 

[carinthian]

Nice lightning display now on the Valletta Skyline webcams in Malta. Maybe someone can upload the live shots over Grand Harbour.?

C

[LightningLover]

Just had some torrential convective rainfall in Bexhill

[Another Kent clipper]

2 hours ago, Another Kent clipper said:

Thunder o'clock soon londoners...

I am so sorry for jinxing it.    Monday rush hour will be interesting if this unelectrified rain keeps up

[Allseasons-Si]

Another batch coming out of Northern France producing some sferics.

[Flash bang flash bang etc]

56 minutes ago, Allseasons-si said:

Another batch coming out of Northern France producing some sferics.

Looks like it’ll just be heavy rain when it gets here unfortunately

[East_England_Stormchaser91]

56 minutes ago, Allseasons-si said:

Another batch coming out of Northern France producing some sferics.

Getting closer now to the south coast. Nothing compared to what’s hitting Majorca yet again. What a week they’ve had there! Been watching another incredible lightning storm on the alcudia cam

[Chris.R]

 Another chance for good ocean effect convection over the weekend. Just waiting for it to come into range of the WRF. Looks like more of a wishbone effect though so not much chance if you’re inland but good for me. 

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Thu 25 Oct 2018 - 05:59 UTC Fri 26 Oct 2018

ISSUED 19:29 UTC Wed 24 Oct 2018

ISSUED BY: Dan

Behind a southward-moving cold front on Thursday night, a cold airmass of Arctic origin will advect southwards across the northern half of the British Isles by Friday morning. This cold air atop relative warm SSTs will result in a few hundred J/kg CAPE, with numerous showers likely which may produce some small hail and a few sporadic lightning strikes (snow also likely over the Scottish mountains).

http://www.convectiveweather.co.uk/forecast.php?date=2018-10-25

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Fri 26 Oct 2018 - 05:59 UTC Sat 27 Oct 2018

ISSUED 19:49 UTC Thu 25 Oct 2018

ISSUED BY: Dan

Arctic airmass continues to sink across all parts of the British Isles during this forecast period, as a cold front clears to the near Continent. Such cold air atop warm SSTs will result in markedly steep lapse rates, and several hundred J/kg CAPE. Numerous showers will develop over seas and affect adjacent land areas exposed to the northwesterly-turn-northerly wind, several producing small hail and sporadic lightning.

Difficult to pinpoint specific areas with a higher risk of lightning, except for acknowledging the risk will be greatest near coasts and over open water. Deeper instability will evolve over the North Sea during the early hours of Saturday, which may suggest lightning could become a little more widespread here (and hence North Sea coastal counties) - perhaps enough to warrant an upgrade to SLGT should confidence improve.

 

http://www.convectiveweather.co.uk/forecast.php?date=2018-10-26

[Weather-history]

 

[Allseasons-Si]

Nice time-lapse that,it looked like night time in those showers.

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Sat 27 Oct 2018 - 05:59 UTC Sun 28 Oct 2018

ISSUED 22:34 UTC Fri 26 Oct 2018

ISSUED BY: Dan

Arctic airmass continues to affect the British Isles, atop warm SSTs and resulting in steep lapse rates and several hundred J/kg CAPE. Numerous showers will continue to develop over seas and affect adjacent land areas exposed to the northerly-turn-northeasterly wind, several producing small hail and sporadic lightning. Organised troughs may allow showers to develop more widely inland for a time.

Difficult to pinpoint specific areas with a higher risk of lightning, except for acknowledging the risk will be greatest near coasts and over open water. Deeper instability will exist over the North Sea during Saturday daytime, shifting to the English Channel overnight, which may suggest lightning could become a little more widespread here - but confidence on coverage is not currently high enough to upgrade to SLGT.

 

http://www.convectiveweather.co.uk/forecast.php?date=2018-10-27

 

[Summer Sun]

Day 1 Convective Outlook

VALID 06:00 UTC Sat 27 Oct 2018 - 05:59 UTC Sun 28 Oct 2018

ISSUED 16:56 UTC Sat 27 Oct 2018

ISSUED BY: Dan

 

UPDATE 16:56 UTC Recent sferics over The Wash associated with a region of maximised low-level convergence, and may continue to feed heavier precipitation across The Fens into north Cambridgeshire over the next hour or two - a low-end SLGT has been issued here. Elsewhere, a couple of other low-end SLGTs have been introduced to try and better highlight areas where some lightning activity is more likely to occur overnight

 

Arctic airmass continues to affect the British Isles, atop warm SSTs and resulting in steep lapse rates and several hundred J/kg CAPE. Numerous showers will continue to develop over seas and affect adjacent land areas exposed to the northerly-turn-northeasterly wind, several producing small hail and sporadic lightning. Organised troughs may allow showers to develop more widely inland for a time.

 

Difficult to pinpoint specific areas with a higher risk of lightning, except for acknowledging the risk will be greatest near coasts and over open water. Deeper instability will exist over the North Sea during Saturday daytime, shifting to the English Channel overnight, which may suggest lightning could become a little more widespread here - but confidence on coverage is not currently high enough to upgrade to SLGT.

 

http://www.convectiveweather.co.uk/forecast.php?date=2018-10-27

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Sun 28 Oct 2018 - 05:59 UTC Mon 29 Oct 2018

ISSUED 17:31 UTC Sat 27 Oct 2018

ISSUED BY: Dan

Cold airmass atop warm SSTs continues to generate showers over the North Sea and English Channel, these then drifting largely west/southwestwards courtesy of an east/northeasterly steering flow. The deepest instability will exist during the first half of the forecast period, especially near the Channel Isles where low-level convergence may provide enough additional forcing for sporadic lightning - as such, a low-end SLGT has been introduced.

Elsewhere, lightning will be rather isolated, and increasingly less-likely as the airmass gradually warms and instability weakens, leading to showers becoming more isolated with time.

 

http://www.convectiveweather.co.uk/forecast.php?date=2018-10-28

[Another Kent clipper]

Don't know if it shows the jist but nice skies today

[Chris.R]

Some lightning off Hollyhead and points west. Wish I was there now.  Seems to have died now though. 

[Summer Sun]

Day 1 Convective Outlook

VALID 06:00 UTC Wed 31 Oct 2018 - 05:59 UTC Thu 01 Nov 2018

ISSUED 08:43 UTC Wed 31 Oct 2018

ISSUED BY: Dan

Some pulses of mid-level instability release continue to be possible as a series of occluded fronts drift eastwards across western and southern Britain on Wednesday and Wednesday night. Some isolated / sporadic lightning may be possible, especially over Wales / SW England where instability will be greatest (but still rather weak).

http://www.convectiveweather.co.uk/forecast.php?date=2018-10-31

[philglossop]

And we’ve a thunderstorm here! Some strong flashing towards Devonport and across the Sound.

Most unexpected  

[wimblettben]

2 minutes ago, philglossop said:

And we’ve a thunderstorm here! Some strong flashing towards Devonport and across the Sound.

Most unexpected  

Are you sure its not fireworks as there can be some this time of year?

If it is lightning, then I do wonder what may come as I no there is suppose to be a risk tonight but its not great.

May be too far inland here anyway.