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Storms and Convective discussion - 28th July 2019 onwards


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Posted
  • Location: Godalming
  • Weather Preferences: Plumes and streamers
  • Location: Godalming
8 hours ago, Summer Sun said:

Day 2 Convective Outlook

VALID 06:00 UTC Thu 24 Oct 2019 - 05:59 UTC Fri 25 Oct 2019

ISSUED 18:45 UTC Wed 23 Oct 2019

ISSUED BY: Dan

A complex pattern will evolve on Thursday, with a largescale upper trough over the Atlantic slowly approaching the British Isles, but also absorbing a portion of the Iberian cut-off upper low as it becomes stretched and pulled northwards over SE England during the middle part of Thursday daytime. The net result will likely see an increase in precipitation coverage and intensity as two frontal boundaries straddling CS / SE England, Midlands and East Anglia become engaged by the increased forcing aloft. Given the presence of a weak thermal plume advected northwards from SW France, embedded deep convection will lead to the threat of heavy rainfall in places, bringing the risk of some localised surface water flooding. 

A few hundred J/kg CAPE seems likely within this plume, which may be sufficient for some sporadic lightning late morning and into the afternoon hours - however, given saturated profiles this aspect is rather uncertain, and confidence is too low to introduce a SLGT. However, we have added an additional area to better highlight where some sporadic lightning could occur - this may be upgraded to a low-end SLGT if confidence improves.

Elsewhere, the post-frontal environment will offer scattered showers in places, most frequent along exposed western and northwestern coasts. In general, the depth of convection will tend to be too shallow / restricted for much in the way of lightning. The deepest convection will be found over NW Scotland.

http://convectiveweather.co.uk/forecast.php?date=2019-10-24

 

A LOW within a LOW, surely that’s a first? 

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Posted
  • Location: Bexhill-on-sea, East Sussex (11.8M ASL)
  • Weather Preferences: Thunderstorms, snow, and wind storms
  • Location: Bexhill-on-sea, East Sussex (11.8M ASL)
12 hours ago, Flash bang flash bang etc said:

A LOW within a LOW, surely that’s a first? 

It’s happened before to my knowledge... Can’t remember the date though. I believe it was a year or two ago?

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Fri 25 Oct 2019 - 05:59 UTC Sat 26 Oct 2019

ISSUED 19:54 UTC Thu 24 Oct 2019

ISSUED BY: Dan

An Atlantic frontal system will affect many parts of Ireland, Wales and England throughout Friday, in an environment with high moisture content in the low-levels and strong shear. As such, some line convection / segments will be possible within the frontal rain, but the risk of lightning is considered too low to warrant any threat levels.

To the north of this frontal boundary an environment with cool air aloft atop reasonably warm SSTs will generate some instability for scattered showers to affect N and W Scotland, and NW Ireland. A few isolated lightning strikes will be possible, more especially towards NW Scotland where convection will tend to be deepest.

http://convectiveweather.co.uk/forecast.php?date=2019-10-25

 

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Sun 27 Oct 2019 - 05:59 UTC Mon 28 Oct 2019

ISSUED 20:49 UTC Sat 26 Oct 2019

ISSUED BY: Dan

An upper trough will slide southeastwards across Scotland and the North Sea on Sunday morning, creating an environment with steep mid-level lapse rates and a few hundred J/kg CAPE. Scattered showers will affect many parts of Scotland, filtering also into NW England, with the potential for a few isolated lightning strikes - more especially during the morning / early afternoon, since instability and convective depth will gradually reduce thereafter.

http://convectiveweather.co.uk/forecast.php?date=2019-10-27

 

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Posted
  • Location: Gourock, Scotland
  • Weather Preferences: Snow, Thunderstorms, Severe Gales, Hot & Sunny or Cold & Sunny!
  • Location: Gourock, Scotland

Morning all!

Another weekend here in Gourock, Scotland of isolated torrential downpours. (Snow over 600 meters)

Pictures looking North West/North/North East. (Cowal Peninsula/Arrochar Alps/Loch Lomond hills)

Some nice cloudscapes and plenty of sunshine in between.

B7DF14C7-2F81-462B-A772-E89CB3A47A9C.thumb.jpeg.c9fcced4ecb8f7fe2b8891955a0c8406.jpegA7FB2A60-8765-4A76-85E2-1117875E9388.thumb.jpeg.fb66c4427b41194a48856185a044eaa3.jpegBD8AFDC4-7A7C-4C83-9C89-DE5C36F1E6E3.thumb.jpeg.7034c78fef89d88c5a081508c6c9d830.jpegC113F102-3D0F-40B2-A7D4-5F001B07C143.thumb.jpeg.5a91b60b7d7b4cc7df03903676074254.jpeg72A7683B-4239-4342-A23B-A93ECE783CD3.thumb.jpeg.096d5dc7f1fbb2fe801e2e992aac3cbb.jpeg62D5D097-8DBC-4A5F-B88B-D0C698EB1C34.thumb.jpeg.acc8734b1543a089c111c50aac493583.jpeg306B7BFC-E342-4269-8B5D-F097DEA57C52.thumb.jpeg.8728e33f317540cf7c9062bc6a675529.jpeg
 

Edited by Mr Frost
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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Thu 31 Oct 2019 - 05:59 UTC Fri 01 Nov 2019

ISSUED 20:23 UTC Wed 30 Oct 2019

ISSUED BY: Dan

As the next Atlantic frontal system arrives, embedded convection on Thursday night may produce the odd isolated lightning strike - however, the risk is considered very low, and most (if not all) areas will remain void of lightning.

http://convectiveweather.co.uk/forecast.php?date=2019-10-31

 

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Sat 02 Nov 2019 - 05:59 UTC Sun 03 Nov 2019

ISSUED 22:20 UTC Fri 01 Nov 2019

ISSUED BY: Dan

An upper low will track slowly across the British Isles on Saturday, with a very deep surface low migrating from the Celtic Sea across the Midlands to the North Sea by the evening. Early showers near southeast England may produce the odd isolated lightning strike. Elsewhere, a wrap-around occlusion will race eastwards across England and Wales, characterised by a band of rain.

The risk of lightning with this feature is very low, with the most likely area considered to be Wales / Bristol Channel where instability, due to proximity to warm waters of the Irish Sea, will be greatest. An increase in deep convection is likely during the evening and night hours across the English Channel, feeding across the Channel Islands and close to the Sussex/Kent coasts - here a few sporadic lightning strikes will be possible.

The environment across southern Britain will be strongly-sheared during Saturday daytime, with backed surface winds creating looped hodographs - however, instability is fairly meagre, which will tend to restrict the tornado risk.

http://convectiveweather.co.uk/forecast.php?date=2019-11-02

 

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Sun 03 Nov 2019 - 05:59 UTC Mon 04 Nov 2019

ISSUED 22:24 UTC Sat 02 Nov 2019

ISSUED BY: Dan

An upper low will sit over the British Isles during Sunday, gradually filling and eventually become absorbed into a separate upper low approaching Ireland from the Atlantic. The net result is an unsettled day with various areas of showery precipitation rotating around these features. Instability is rather meagre, which combined with somewhat limited convective depth the overall risk of lightning is considered very low, and for most places lightning is unlikely to occur.

A slightly better environment may evolve on Sunday night over the Celtic / Irish Sea into Wales / SW England, with steeper mid-level lapse rates and a couple hundred J/kg CAPE. Here, better prospects for a few sporadic lightning strikes is expected, but unlikely to be widespread or frequent enough to warrant a SLGT. Nonetheless, one or two waterspouts may occur.

http://convectiveweather.co.uk/forecast.php?date=2019-11-03

 

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Mon 04 Nov 2019 - 05:59 UTC Tue 05 Nov 2019

ISSUED 20:38 UTC Sun 03 Nov 2019

ISSUED BY: Dan

Large upper vortex will reside over the British Isles throughout Monday, creating an environment with steep mid-level lapse rates and a few hundred J/kg CAPE in response to SSTs. While persistent rain will affect portions of Scotland, scattered showers will affect many other areas, particularly coastal counties exposed to an onshore flow since the deepest convection will generally be found over open waters of the Irish / Celtic Seas and English Channel.

Unlike previous days, convective depth should be significantly deeper although weak shear and rather saturated profiles will tend to inhibit much in the way of lightning. A few isolated strikes will be possible, with the greatest risk considered over the English Channel (especially close to the Channel Islands), and as such a low-end SLGT has been introduced. The Bristol Channel and coasts of SW Wales / N Devon / N Cornwall could be another area where some sporadic lightning may occur, but with lower confidence. This overall setup is conducive to a few funnel clouds or waterspouts.

http://convectiveweather.co.uk/forecast.php?date=2019-11-04

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Posted
  • Location: St Neots, previously Billericay & Brentwood
  • Weather Preferences: Thunder, snow, gales, all extreme weather really!
  • Location: St Neots, previously Billericay & Brentwood
On 27/10/2019 at 05:23, Mr Frost said:

Morning all!

Another weekend here in Gourock, Scotland of isolated torrential downpours. (Snow over 600 meters)

Pictures looking North West/North/North East. (Cowal Peninsula/Arrochar Alps/Loch Lomond hills)

Some nice cloudscapes and plenty of sunshine in between.

B7DF14C7-2F81-462B-A772-E89CB3A47A9C.thumb.jpeg.c9fcced4ecb8f7fe2b8891955a0c8406.jpegA7FB2A60-8765-4A76-85E2-1117875E9388.thumb.jpeg.fb66c4427b41194a48856185a044eaa3.jpegBD8AFDC4-7A7C-4C83-9C89-DE5C36F1E6E3.thumb.jpeg.7034c78fef89d88c5a081508c6c9d830.jpegC113F102-3D0F-40B2-A7D4-5F001B07C143.thumb.jpeg.5a91b60b7d7b4cc7df03903676074254.jpeg72A7683B-4239-4342-A23B-A93ECE783CD3.thumb.jpeg.096d5dc7f1fbb2fe801e2e992aac3cbb.jpeg62D5D097-8DBC-4A5F-B88B-D0C698EB1C34.thumb.jpeg.acc8734b1543a089c111c50aac493583.jpeg306B7BFC-E342-4269-8B5D-F097DEA57C52.thumb.jpeg.8728e33f317540cf7c9062bc6a675529.jpeg
 

The 3rd and 4th photos in particular are fantastic with that rainbow popping out almost like a lightning strike-great capture! 

Edited by James1979
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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Wed 06 Nov 2019 - 05:59 UTC Thu 07 Nov 2019

ISSUED 21:51 UTC Tue 05 Nov 2019

ISSUED BY: Dan

The next Atlantic frontal system will spread bands of cloud and rain across many parts of the British Isles through Wednesday and Wednesday night. The passage of the second occlusion will be within an environment with a few hundred J/kg CAPE over the open waters of the Celtic / Irish Seas and English Channel, and this combined with engagement with the left exit of a mid-level jet is likely to result in an increase of embedded convection, and so a few isolated lightning strikes may occur during the evening hours - primarily over open seas, but also potentially close to coastal areas in the south and west.

The post-frontal environment is then characterised by more typical open cell convection, as cold air aloft overspreads the relatively warm seas - this primarily affecting the Celtic Sea, and then later into SW England / S Wales and the English Channel. A few sporadic lightning strikes will be possible from scattered showers in this regime during Wednesday night.

http://convectiveweather.co.uk/forecast.php?date=2019-11-06

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Thu 07 Nov 2019 - 05:59 UTC Fri 08 Nov 2019

ISSUED 20:22 UTC Wed 06 Nov 2019

ISSUED BY: Dan

An increasingly elongated, multi-centred area of low pressure will become slow-moving across the British Isles on Thursday, with a wrap-around occlusion providing a band of persistent rain on its northern flank over portions of Wales / Midlands / East Anglia / northern England and Ireland. To the south of the low, cold air aloft overspreading relatively warm seas will generate a few hundred J/kg CAPE, with scattered showers affecting many parts of the Celtic Sea and English Channel, feeding farther inland across southern England and south Wales. A few lightning strikes will be possible, primarily over open waters, and extending into the southern North Sea on Thursday night. This type of setup has in the past yielded a few funnel clouds/waterspouts, and remains a possibility given steep low-level lapse rates and converging winds near the elongated surface low centre.

http://convectiveweather.co.uk/forecast.php?date=2019-11-07

 

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Sat 09 Nov 2019 - 05:59 UTC Sun 10 Nov 2019

ISSUED 19:39 UTC Fri 08 Nov 2019

ISSUED BY: Dan

As the upper trough over Ireland disrupts, the Atlantic frontal zone and associated band of cloud/rain will tend to stall over Wales / Midlands / S England / Northern Ireland, before eventually pulling away to the south. Behind this front, the post-frontal environment will be characterised by cool air aloft atop relatively warm SSTs, resulting in steep mid-level lapse rates and a few hundred J/kg CAPE. As such, scattered showers will affect parts of Ireland, and later into Wales and SW England, and eventually the Channel Islands from Saturday evening onwards. A few isolated lightning strikes may occur with this activity.

During the early hours of Sunday, scattered showers will likely return to some parts of eastern England from the North Sea - but the shallow nature of this convection suggests the risk of lightning is very low.

http://convectiveweather.co.uk/forecast.php?date=2019-11-09

 

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Sun 10 Nov 2019 - 05:59 UTC Mon 11 Nov 2019

ISSUED 17:00 UTC Sat 09 Nov 2019

ISSUED BY: Dan

An upper vortex close to the Channel Islands early on Sunday morning will quickly retreat southwards across France, leaving much of the British Isles under broad upper ridging during daylight hours. Late in the afternoon the next Atlantic frontal system will arrive, spreading cloud and rain across Ireland initially, and then most of Britain through Sunday night.

The post-frontal environment will arrive across western Ireland by late evening, then spread across the Irish Sea into western Britain during the early hours of Monday. This will be characterised by cool air aloft atop relatively warm SSTs, resulting in steep mid-level lapse rates and a few hundred J/kg CAPE. As such, scattered showers will affect parts of Ireland, and later into W / NW Britain. A few isolated lightning strikes may occur with this activity.

http://convectiveweather.co.uk/forecast.php?date=2019-11-10

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Mon 11 Nov 2019 - 05:59 UTC Tue 12 Nov 2019

ISSUED 21:48 UTC Sun 10 Nov 2019

ISSUED BY: Dan

The British Isles will be situated under an upper trough (particularly the axis and rear side) throughout Monday, the associated cold pool aloft atop relatively warm seas and diurnal heating inland creating an unstable environment with steep mid-level lapse rates and 300-600 J/kg CAPE over open waters. As a result, behind the main frontal rain - which will tend to linger over N / NW Scotland - scattered showers are expected fairly widely across Ireland, the Irish Sea and western Britain, feeding well-inland on brisk northwesterly winds. A few sporadic lightning strikes will be possible, along with gusty winds and small hail.

http://convectiveweather.co.uk/forecast.php?date=2019-11-11

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Wed 13 Nov 2019 - 05:59 UTC Thu 14 Nov 2019

ISSUED 20:11 UTC Tue 12 Nov 2019

ISSUED BY: Dan

Scattered showers will be feeding through the North Channel into SW Scotland, NW England and N + W Wales on Wednesday morning, but are expected to gradually weaken through the day. Elsewhere, showery bursts of rain will spread across Ireland and then into SW Britain, the post-frontal environment then yielding several hundred J/g CAPE with scattered showers and some sporadic lightning possible on Wednesday night - although this primarily over open waters of the Celtic Sea and English Channel. This is where the bulk of any (however isolated) lightning activity is expected during this forecast period. Such setups can occasionally produce a few funnel clouds and/or waterspouts.

Additional showers are also likely to develop over northern Scotland and eastern England, particularly overnight where they will tend to feed farther inland - but the instability and depth of convection probably too weak/shallow for much in the way of lightning.

http://convectiveweather.co.uk/forecast.php?date=2019-11-13

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Thu 14 Nov 2019 - 05:59 UTC Fri 15 Nov 2019

ISSUED 20:30 UTC Wed 13 Nov 2019

ISSUED BY: Dan

Cold pool associated with a disrupting upper trough on Thursday will generate an environment with steep mid-level lapse rates and a couple hundred J/kg CAPE. Scattered showers will affect many coastal areas exposed to the onshore wind, perhaps with an isolated lightning strike. The greatest risk of lightning (albeit still relatively low) will be through the English Channel.

http://convectiveweather.co.uk/forecast.php?date=2019-11-14

 

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Fri 15 Nov 2019 - 05:59 UTC Sat 16 Nov 2019

ISSUED 19:41 UTC Thu 14 Nov 2019

ISSUED BY: null

A few isolated lightning strikes may be possible from scattered showers running down the Irish Sea and English Channel on Friday.

http://convectiveweather.co.uk/forecast.php?date=2019-11-15

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Wed 20 Nov 2019 - 05:59 UTC Thu 21 Nov 2019

ISSUED 18:59 UTC Tue 19 Nov 2019

ISSUED BY: Dan

Atlantic upper trough will continue to dig towards Biscay, becoming increasingly negatively-tilted while slowly approaching the British Isles from the southwest. A couple of frontal boundaries will become quasi-stationary over the Celtic Sea and portions of Ireland, with renewed pulses of rain running N / NW-wards along the fronts. Embedded convection seems likely at times, in an environment with a few hundred J/kg CAPE - and hence there will be an ongoing (low) chance of a few isolated lightning strikes. Of greater concern is the risk of localised flooding in southern Ireland, where heavy bursts of rain may become prolonged at times.

http://convectiveweather.co.uk/forecast.php?date=2019-11-20

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Day 2 Convective Outlook

VALID 06:00 UTC Thu 21 Nov 2019 - 05:59 UTC Fri 22 Nov 2019

ISSUED 20:32 UTC Wed 20 Nov 2019

ISSUED BY: Dan

A similar setup to previous days, as pulses of showery rain spread slowly N / NW-wards across southern Britain and southern / western Ireland on the forward side of a negatively-tilted upper trough. A few isolated lightning strikes may be possible, mainly over the English Channel on Thursday night - but most areas will remain void of any lightning. Of greater concern is probably the risk of some localised flooding where heavy bursts of rain become prolonged at times, more especially over S / SE Ireland.

http://convectiveweather.co.uk/forecast.php?date=2019-11-21

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