Convective/Thunderstorm Discussion : 2019 and Winter 2020

PukkaStukka · 02-06-2019 7:11pm

Kudos to you if you're right Meteorite, you've been flagging this for two days now and your hunches are usually good

Mortelaro · 02-06-2019 11:00pm

https://www.instagram.com/p/ByNIgrjCHll/?igshid=1c9fsfdnhdyic

Meteorite58 · 03-06-2019 10:37am

PukkaStukka wrote: »

Kudos to you if you're right Meteorite, you've been flagging this for two days now and your hunches are usually good

In the end only a few sferics showed up, there was more activity further N in Scotland. By the looks of it the rainfall in Connaught and Ulster wasn't as heavy also.

Iancar29 · 03-06-2019 4:16pm

Two nice lil captures of last weeks storm. Hopefully some more action over the coming days.

pad199207 · 03-06-2019 4:27pm

Hefty Downpours here in Kildare now

Reckless Abandonment · 03-06-2019 4:28pm

Welcome back Ian. Great shots

Meteorite58 · 04-06-2019 7:58pm

Best of the sunlight and diurnal heating in the Southern half of the country tomorrow. Lapse rates best here with the cold air aloft . Not much LLS and very little if any DLS but with enough clear spells to allow convection to mature could be seeing some sporadic heavy downpours in the afternoon with the chance of isolated thunderstorms.

Also an area of interest would be along Southern coasts later in the afternoon where CAPE may be at it's highest with the aid of convergence. The models are showing the Cork coast especially as an area that could get active in the afternoon.

Meteorite58 · 04-06-2019 8:26pm

Yeah thinking that convection might mature from a NW direction and with the extra bit of afternoon heat along the S coast ,especially in Cork aided by coastal convergence , might produce some lightning activity along the coast , maybe more so over water.

Meteorite58 · 04-06-2019 11:27pm

Thurs, IMO, looking like a potentially active day for convection with heavy thundery showers .

Again cold pool of air aloft, diurnal heating aided by local convergence overland with modest LLS and the passage of a trough could produce the sparks.

Meteorite58 · 05-06-2019 9:45am

Big shower of hail a few minutes ago here in Tralee . Towering clouds out there today.

Oneiric 3 · 05-06-2019 9:50am

Terrific video here showing some great examples of 'positive lightning' strikes from an active storm in the US a couple of years back:

https://www.youtube.com/watch?v=RG3JF7GRfRE

Meteorite58 · 06-06-2019 12:24am

Plenty of convection with some hail and plenty of heavy rain showers today . Heavy showers along southern coasts with a few sferics showing up but not a lot.

Possibility for convection to become charged up again tomorrow with plenty of moisture in the atmosphere and a negative tilted trough being forecast by estofex giving instability. Little in the way of deep layer shear but some Low level shear and areas of convergence. Cool pool of air aloft with some breaks in the cloud letting the sun through long enough could aid the development of convection producing sporadic thunderstorms me thinks. Messy enough though. Slim pickings lately on the wrong side of marginal.

Nothing like what's shown in the excellent video posted by Oneric 3 , will have to go to Oklahoma for that

Will see what tomorrow brings.

Meteorite58 · 06-06-2019 8:14am

Day 1 Convective Outlook
VALID 06:00 UTC Thu 06 Jun 2019 - 05:59 UTC Fri 07 Jun 2019

ISSUED 06:17 UTC Thu 06 Jun 2019

ISSUED BY: Dan

Upper low west of the British Isles will elongate and sharpen, with cold mid-levels creating steep mid-level lapse rates. Early very active elevated thunderstorms over the central North Sea will tend to weaken somewhat as they continue to nudge north towards or to the east of Shetland.

Elsewhere, diurnal heating will yield 300-500 J/kg MLCAPE with scattered showers developing, particularly aided by areas of low-level convergence. By the afternoon, dewpoints of 6-8C seem likely (GFS typically too moist).
A few thunderstorms will be possible - instability will be greater over Ireland (due to proximity to upper cold pool) but with weaker shear, so more "pulse-type" convection seems likely here, whereas over Britain instability will be less but with stronger shear on the forward-side of the upper trough, lending to slightly better cell organisation. As such, have issued a couple of low-end SLGTs to better highlight areas with reasonable multi-model agreement for a few sporadic lightning strikes.

Some uncertainty exists over Northern Ireland, depending on how much cloud may linger courtesy of the nearby wrap-around occlusion. However, the slack regime would support the development for scattered showers and/or a few thunderstorms should cloud breaks be sufficient for reasonable surface heating to occur - this area will need monitoring for a potential upgrade.

On Thursday night, a rapidly deepening area of low pressure will approach from Biscay, pushing frontal rain northwards across the English Channel into S / SW England. There may be some pockets of embedded elevation convection, but any lightning will probably fairly isolated.