Storms and Convective discussion - November 2023 onwards

[Supacell]

Where November is not traditionally a month associated with storms for inland areas of the UK, it can still be quite thundery around the coastlines. Much like has been the case for the second half of October, the first week of November shows up risks for scattered thunderstorms around southern and western coasts particularly. Infact, there is scope for some quite severe storms in the next 48 hours courtesy of Storm Ciarán (and before).

Look back on October here.

Keep on posting all thunderstorm and convective related musings for the final Autumn month in here.

Edited November 1, 2023 by Supacell

[Jo-anne]

Has weather bug got issues it keeps giving me a thunderstorm warning there's 3 tomorrow 8am then 12pm and 4pm it's 80% chance, I'm no where near warning areas on other maps, it's confusing for me.

[Flash bang flash bang etc]

Pls stop starting new threads so frequently, I have to update all my links

[Thunderspotter]

3 hours ago, Jo-anne said:

Has weather bug got issues it keeps giving me a thunderstorm warning there's 3 tomorrow 8am then 12pm and 4pm it's 80% chance, I'm no where near warning areas on other maps, it's confusing for me.

From my findings, WeatherBug only tends to be good with its lightning detector. I moved away from them as they seem to generalise the forecast a lot - leading to lower accuracy.

[Metwatch]

One of the best mammatus displays I've seen in quite a long while this afternoon from a passing hail shower! 

Edited November 1, 2023 by Metwatch

[Sprites]

4 hours ago, Jo-anne said:

Has weather bug got issues it keeps giving me a thunderstorm warning there's 3 tomorrow 8am then 12pm and 4pm it's 80% chance, I'm no where near warning areas on other maps, it's confusing for me.

I'd say thunder is more likely further south, quite a low risk of thunder in Derbyshire tomorrow. 

[Metwatch]

2 hours ago, Flash bang flash bang etc said:

Pls stop starting new threads so frequently, I have to update all my links

Yeah agreed, I think if we could keep the same thread until March now as it's won't be as active, would be a lot better. No issue with up to 75, 100 ish pages each convective thread, little point switching to a new one if there's only like 10 pages of content @Supacell

[Jo-anne]

2 hours ago, Thunderspotter said:

From my findings, WeatherBug only tends to be good with its lightning detector. I moved away from them as they seem to generalise the forecast a lot - leading to lower accuracy.

Thank you they had been okay but just lately not! What do you use if you dont mind me asking. ☺ 

[matt111]

Just had some very heavy rain from those showers ahead of the main area of rain, although looking at the radar it seems they're being swallowed by the rest of the rain now. The wind has increased a bit and the pressures started falling quickly. 

Meant to post that in the Storm Ciarán thread but it's also appropriate here I guess since there is a risk of convective activity amongst everything else tonight. 

Edited November 1, 2023 by matt111

[Thunderspotter]

46 minutes ago, Jo-anne said:

Thank you they had been okay but just lately not! What do you use if you dont mind me asking. ☺ 

Sorry for my late reply, just had dinner.

 

I use an app called "WeatherandRadar", and they also have a website www.weatherandradar.co.uk

 

They can and do get stuff wrong every now and again, but from my research they seem to get the highest accuracy. 

Also as a side note i use Accuweather sometimes, but only for their minute-by-minute forecasts. I never trust any other forecast from them though

[Eagle Eye]

Convective Outlook️ 

With Storm Ciaran hitting throughout Thursday morning and into the mid-late afternoon hours, maybe lingering into the late evening, it'll bring heavy showers with it with on and off blustery showers mixed in with longer spells of rain. Mainly along the south coast for the wind but some severe windy conditions up to Cambridge area possible and a similar line for the blustery showers to form. Some more frontal rain not associated with much of a risk except a sparodic lightning strike further north.

 

There is some CAPE around, with areas of 500+ J/KG of MLCAPE and so some sparodic strikes throughout the storms length is possible.

 

As the storm reaches Cornwall early morning, some sparodic lightning is possible along with 90+ mph wind gusts along the coasts and 70+ mph gusts inland.

 

Ahead of the main intense wind gusts, some heavy showers in area of 200+ 3CAPE could move into the SE. This has large buoyancy and suggests some hail potential. However, the LLS being in excess of 50 knots in some places also means thst if vorticity can be stretched streamwise, there's some tornadic potential.

 

Along the south coast and slightly inland, there's a general chance of a tornado throughout the storm with the LLS available. The biggest potential does appear to be with that SE risk. Any tornado is likely to be brief and weak though. However, a sig tor parameter of potentially 0.4 is something to keep an eye on as its fairly rare for the UK.

 

Later into the morning, the rain becomes more frontal in the SW but the wind keeps up till late morning, slowing down from the peak in the early afternoon and in the late afternoon slowed down to sub severe wind gusts. Similar timings along the south coast and into the SE but may not leave till late evening. The strongest wind gusts in the S and SE looks to be in that 90 mph region, in the channel, 110+ mph wind gusts possible. Further north and upto Cambridge sort of line, peak wind gusts are more likely to be late morning and early afternoon where the storm peaks in Northern extent of wind gusts. As with friction, wind gusts look more likely to peak at 50mph widespread rather than the extremes along the coasts.

 

With the amount of blustery rain and frontal rain, places along the south coast and inland up to the M5 line could see 50+ mm of rain in 24 hours. Further north and some places could reach 30+ mm of rain in 24 hours. The SWISS-EZ4 even peak around 80+ mm of rain in isolated spots in the SW.

 

So severe wind gusts, flooding, small hail and isolated lightning, mainly in the very early morning, are all possible. Along with a chance of isolated tornado, mainly in the very early morning hours, main chance being in the SE.

[Thunderspotter]

51 minutes ago, Eagle Eye said:

Convective Outlook️ 

With Storm Ciaran hitting throughout Thursday morning and into the mid-late afternoon hours, maybe lingering into the late evening, it'll bring heavy showers with it with on and off blustery showers mixed in with longer spells of rain. Mainly along the south coast for the wind but some severe windy conditions up to Cambridge area possible and a similar line for the blustery showers to form. Some more frontal rain not associated with much of a risk except a sparodic lightning strike further north.

 

There is some CAPE around, with areas of 500+ J/KG of MLCAPE and so some sparodic strikes throughout the storms length is possible.

 

As the storm reaches Cornwall early morning, some sparodic lightning is possible along with 90+ mph wind gusts along the coasts and 70+ mph gusts inland.

 

Ahead of the main intense wind gusts, some heavy showers in area of 200+ 3CAPE could move into the SE. This has large buoyancy and suggests some hail potential. However, the LLS being in excess of 50 knots in some places also means thst if vorticity can be stretched streamwise, there's some tornadic potential.

 

Along the south coast and slightly inland, there's a general chance of a tornado throughout the storm with the LLS available. The biggest potential does appear to be with that SE risk. Any tornado is likely to be brief and weak though. However, a sig tor parameter of potentially 0.4 is something to keep an eye on as its fairly rare for the UK.

 

Later into the morning, the rain becomes more frontal in the SW but the wind keeps up till late morning, slowing down from the peak in the early afternoon and in the late afternoon slowed down to sub severe wind gusts. Similar timings along the south coast and into the SE but may not leave till late evening. The strongest wind gusts in the S and SE looks to be in that 90 mph region, in the channel, 110+ mph wind gusts possible. Further north and upto Cambridge sort of line, peak wind gusts are more likely to be late morning and early afternoon where the storm peaks in Northern extent of wind gusts. As with friction, wind gusts look more likely to peak at 50mph widespread rather than the extremes along the coasts.

 

With the amount of blustery rain and frontal rain, places along the south coast and inland up to the M5 line could see 50+ mm of rain in 24 hours. Further north and some places could reach 30+ mm of rain in 24 hours. The SWISS-EZ4 even peak around 80+ mm of rain in isolated spots in the SW.

 

So severe wind gusts, flooding, small hail and isolated lightning, mainly in the very early morning, are all possible. Along with a chance of isolated tornado, mainly in the very early morning hours, main chance being in the SE.

Great forecast as usual. Looks like there's more convection than expected!

[mike5900]

Just seen lightning.

[Thunderspotter]

Some very strong storms moving into Dorset atm, looks like the channel is cooking up a few storms here and there!

[Thunderspotter]

Wow. You could tell me that this screenshot was in the middle of summer and I'd believe you!

[Flash bang flash bang etc]

I’m spying potential for some fairly active electrical storms. My only questions are where and when.

CAPE is apparently low (about 100 > 300 J/KG) which isn’t too much of an issue as a lot of that is low to the ground (Eagle mentioned this as 3CAPE) which means there is more potential than one would initially expect.

But this is the U.K. so the timings and placements could vary wildly and I’m not open to speculation.

In essence: an exciting night to come, for some! That said please take care if venturing outside and be aware that things could get very blustery

[ChannelThunder]

Been so locked into the Ciaran thread I nearly forgot to check in here!

Did someone order a November Spanish plume with a side dish of gales?

 

Edited November 1, 2023 by ChannelThunder

[Tamsin]

4 hours ago, Metwatch said:

...if we could keep the same thread until March now as it's won't be as active, would be a lot better.  @Supacell

Haha, it could end up being a very big thread indeed considering we're on our 12th consecutive thunder day!

[Thunderspotter]

Just now, ChannelThunder said:

Been so locked into the Ciaran thread I nearly forgot to check in here!

Did someone order a November Spanish plume with a side dish of gales?

 

That's my order!!

 

[Thunderspotter]

Just freed up over 25gb of storage on my phone in preparation for this, lets hope it is a show that fills up that storage fast!!

[Thunderspotter]

Beginning to get slightly concerned that the storms are moving North too much - Just needs to drift east a little bit for me to be able to see it

[Metwatch]

Repost from Storm Ciaran thread, on a live Jersey cam.

[Thunderspotter]

Bournemouth is booming now!

[Zak M]

Golf-ball-sized hail in Jersey... in November

[Thunderspotter]

Where'd all the channel action go? Was looking forward to it.

 

I guess better go to bed now. Not much worth staying up and adding to tomorrows workload! Night everyone