Storm Isha, Amber ⚠️

[HurricaneSteve]

1 minute ago, WYorksWeather said:

Now deepened to 961mb.

Latest GFS has it down to 947, so more deepening to go

[birdman]

6 minutes ago, HellItsHot said:

Why anyone would object to weather warnings because of  political correctness’ or any other such nonsense is quite the mystery. 

Yes it's unbelievable really and just shows how some people live in a bubble. Unfortunately it's likely some poor soul will lose their life from this storm. One bad decision or wrong place wrong time and it's game over. The warning are there to minimise such things and prepare accordingly. Stay safe everyone  

[Mcconnor8]

Just now, WYorksWeather said:

Now deepened to 961mb.

UKV 09z run looks to be deeper than the 06z with higher gusts.

The ICON 09z run is also a couple of mb deeper than the 06z run, it has the storm at 950mb strength by 5PM

[WYorksWeather]

Here is the Meteociel wind gust observation chart as well:

Highest so far seems to be 116km/h (72 mph) at Capel Curig (admittedly at over 200m ASL). Definitely think the most exposed areas could approach 100mph.

[Fiona Robertson]

Motoring along quite nicely right now, thank you very much. 

[WYorksWeather]

Just now, Mcconnor8 said:

UKV 09z run looks to be deeper than the 06z with higher gusts.

The ICON 09z run is also a couple of mb deeper than the 06z run, it has the storm at 950mb strength by 5PM

Thanks for this, will be interesting to see how well the deepening conforms with observations.

[The Tall Weatherman]

I am fed up with this account on TikTok. Dark predictions has no clue about weather and does not even live in the UK. Despite this he racks in millions of viewers who can’t be bothered to look at the actual forecast.

[Wivenswold]

I'll be delighted if this storm finishes-off our rotten old conservatory.

@The Tall Weatherman You know what to do, start your own channel. There's money to be made from clicks.

Edited January 21 by Wivenswold

[birdman]

Just now, Wivenswold said:

I'll be delighted if this storm finishes-off our rotten old conservatory.

Can we have live updates please? 

[Jo Farrow]

Met Office surface pressure and YR satellite https://www.met.no/en/weather-and-climate/satellite-images 

 

[Thunders]

2 minutes ago, The Tall Weatherman said:

I am fed up with this account on TikTok. Dark predictions has no clue about weather and does not even live in the UK. Despite this he racks in millions of viewers who can’t be bothered to look at the actual forecast.

i see him on my fyp too. he always uses clickbait words.  

[Penguin16]

16 minutes ago, Jo Farrow said:

The amber over Scotland has a low likelihood of HIGH impacts now

NW,NE England and NI also included in that. 
Do you think a red may be issued?

Edited January 21 by Penguin16

[Jo Farrow]

Just now, Penguin16 said:

NW,NE England and NI also included in that. 

Yes, can you include your location area in bio, ta

[Ian Ballinger]

4 minutes ago, birdman said:

Can we have live updates please? 

I think we need a live stream

[rwtwm]

2 hours ago, IanT said:

It’s winter here in the UK.

A storm can be a storm without being historic.

A cold spell can be a cold spell without being historic - as we have just seen.

Would it benefit us to return to a time when forecasts were forecasts without hype?

 

In the pages I've read, and the forecasts I've watched this morning, I've seen 'violent', 'potentially damaging', 'severe' and a debate about wether this is a one in 2 or one in 5 year event. 

Yours is the first mention of 'historic' I've seen.

[Supacell]

A rough night ahead for many in what has been a rough season. To have 70mph wind gusts forecast for here is a rarity and for such a long period of time is even more rare. 90mph + winds are a rarity anywhere in the UK aside from on top of a mountain.

Storm Pia was around 60mph I think in these parts and that felled numerous trees, knocked roof tiles off houses, including in the centre of town, and caused a lot of disruption across the county. To think this could be 10mph more! Granted there are other things to take into account, for example the ground was sodden.

I read someone's post (I think on here) that pointed out that wind speed related to the likelihood of damage is logarithmic. The increase of force on a structure caused by a wind of 70mph as opposed to 60mph is greater than the increase of force caused by 60mph as opposed to 50mph and so on. I am not clever enough to work out exactly by how much but there is a calculation out there.

[lorenzo]

The wrap up continues - nice satellite loop from yr.no to highlight

https://www.met.no/en/weather-and-climate/satellite-images

[StingJet]

Fairly common for my neck of the woods , although seeing F11 on the inshore waters forecast is "quite rare"  .. battened down now, winds gusting  up at F9+



I would anticipate Isha's cold front will be quite an aggressive feature, more than likely responsible for some of the inland peak winds

Edit: Added link to Torro, in keeping with Eagle Eye's detailed & informative post 

https://www.torro.org.uk/forecast

Edited January 21 by StingJet

[DevinW]

15 minutes ago, The Tall Weatherman said:

I am fed up with this account on TikTok. Dark predictions has no clue about weather and does not even live in the UK. Despite this he racks in millions of viewers who can’t be bothered to look at the actual forecast.

I got banned by him for saying you should listen to the met office and not him 

[viking_smb]

16 minutes ago, The Tall Weatherman said:

I am fed up with this account on TikTok. Dark predictions has no clue about weather and does not even live in the UK. Despite this he racks in millions of viewers who can’t be bothered to look at the actual forecast.

Tik tok is a joke anyway 

Just now, DevinW said:

I got banned by him for saying you should listen to the met office and not him 

dont worry about it lol 

[Wivenswold]

This isn't going to be a 1987-type event but from my experience from my railway days, it takes one weak tree to bring whole region's transport infrastructure to a standstill. It's just a bit more likely in the Amber warning area.
Likewise with the power grid. So prepare for the worst even if it turns out to be a non-event in your neck of the woods.

Conservatory Cam is doable but I think Big Jet TV on You Tube will be more interesting.

Edited January 21 by Wivenswold

[Jo Farrow]

1 minute ago, Supacell said:

A rough night ahead for many in what has been a rough season. To have 70mph wind gusts forecast for here is a rarity and for such a long period of time is even more rare. 90mph + winds are a rarity anywhere in the UK aside from on top of a mountain.

Storm Pia was around 60mph I think in these parts and that felled numerous trees, knocked roof tiles off houses, including in the centre of town, and caused a lot of disruption across the county. To think this could be 10mph more! Granted there are other things to take into account, for example the ground was sodden.

I read someone's post (I think on here) that pointed out that wind speed related to the likelihood of damage is logarithmic. The increase of force on a structure caused by a wind of 70mph as opposed to 60mph is greater than the increase of force caused by 60mph as opposed to 50mph and so on. I am not clever enough to work out exactly by how much but there is a calculation out there.

and that the MO warnings look at the likelihood of strong winds/heavy rain etc against impacts to come up with the chosen colour warning. 

MO "These impacts can include damage to property, travel delays and cancellations, loss of water supplies, power cuts and, in the most severe cases, bring a danger to life. We show this combination of impact and likelihood in a matrix"  

So Sunday night may not see as many impacts as say the same weather event on Monday morning, nor a core of severe gales hitting the M4  as Highland Scotland. But for individuals there is still the risk of dangerous conditions and incidents.

A good mention there of the sodden ground too

 

[The PIT]

Problem is a tree through the roof has the same impact at 12:00 as it does at 00:00hrs.

Warning should be based solely on the expected speeds regardless whether it's ten sheep in the peak district to 50 sheep in a park in town.

[Eagle Eye]

16 hours ago, Eagle Eye said:

Convective Outlook for it as all the wind warnings have already been done really.

The UK on the south side of a significant low with the stronger gusts should experience significant gusts potentially in excess of 80mph Sunday through Monday morning and further north the risk for severe wind gusts goes through Monday.

 

A couple models are even showing 95+ mph in Northern Scotland and occasionally hitting the Irish coasts. The UKV especially strong on this with 105mph in Northern Scotland and western Ireland. I find this unlikely just given the UKV's tendency to over strengthen the winds but it shows what's possible. 

 

Most of the UK not just the coasts could well see 50+ mph wind gusts, yes the land based friction will have some effect but given how strong the low is, we'll still likely see severe level winds throughout the UK and Ireland. It's especially interesting to see the widespread 100 mph 850's on the south side of this low when it's over the UK to show you how strong this low is. Surface friction and the viscous layer is therefore an extremely important dynamic in just how strong this low can be at the surface here.

 

Thunderstorm potential wise and the cyclonic vorticity ejects out PV lobes towards the SE of the lows centre which we normally wouldn't be hit by as its rare for a low to be this well placed for us but Ireland gets the full strength of the PV lobes latching onto WAA which drives line based thunderstorm developed perhaps stretched more horizontally with shear stretched storms. The push of WAA means that there's a Theta-E drive that on the backend of is where the PV lobes generally are found through mostly Ireland and this is where the best thunderstorm potential potentially is but the high saturation weakens that.

 

Apart from that, general lightning risk throughout most of the UK and Ireland with the energy just generally around. Mostly sporadic though.

 

Tornadic risk is mostly with high LLS combining with 100+ J/KG of 3CAPE, mainly in Ireland and despite the crosswise stretched showers andor thunderstorms, the 3CAPE and vorticity crossover with any ejected PV lobes means that for the UK there's a fairly high tornadic parameter. The streamwsie vorticity would come from a broken line segment, so keep an eye out for those. So there's a genuine potential for a tornado within all the straight line winds but would probably need a less saturated area of shower formation to actually work. Also a small chance with some weak line convection Sunday night over parts of the  midlands.

Update on the tornadic potential. Using the 3CAPE and low-level vorticity lobes, the potential energy for rotation crossover is mostly the best through the middle of Ireland. The 'cheat' for tornadic forecasting is a crossover between 3CAPE and low-level vorticity. I'd probably want 925hPa vorticity but I'm not paying for that so this will have to do. Now comes the problem of very stretched shear so mostly linear mode. General tornadic potential will come from a broken line, whether that precedes potential energy for rotation or it's opposite way around I don't know so I won't really bother trying. 

[cj114]

Just had a look at Dark predictions. I was surprised to see that most of the UK seems to be in Ireland. Had no idea it had moved!

Seriously, I do hope people are not taking this Guy seriously.