Weathizard

Key difference, Iberian heights, it’s always the same, the models can be far too overzealous in removing them at times

I do find it mildly disappointing really that we are now looking out for wedges and ridges, our proper GH has slowly wained away, at day 5 it looks absolutely primed but unfortunately we don’t ever get a clean cut off high and that LP system pumps up the Iberian heights, most cold spells in the UK start with a low undercutting a ridge or HP cell and engaging cold air to our north/east, at the moment we are lacking that proper trigger because of the issues I’ve been banging on about Don’t get me wrong we could still strike lucky, but it just shows how one ingredient out of 20 being wrong and 19 being right can still spoil the party for us.

Heights to our south remain a big issue for me here, it means any cold airmass tracking south will struggle, with the way our HP cell is being squeezed it’s hard to see how we can rid ourselves of them, seen this many times before where we have good hemispheric Synoptics in general but whilst heights to our south remain high any sustained cold is a real pain in the

Trouble is by the time the trigger low comes through to get the cold air in we have no blocking left, making any event fairly transient

I don’t know if I’m imagining this but does the arrival of the cold air just keep getting pushed back? It’s something that’s happened before and I don’t like it, feels like it’s been at 216/240 area for about 4 days.

Bit of a Dogs dinner of a chart from what looked like such a clean evolution at 168 36 hours later

We are about to snatch defeat from the jaws of victory here aren’t we…

My only worry is the way that low pressure is inflating the Iberian heights, quite significant heights building to our south here

Surely we have a stonker incoming here?

Considerable difference in the orientation and strength of that LP at day 4

Encouraging, Quite important given the GFS/EC difference in that key area of low pressure tracking up the ESB, that is where my eyes are drawing to at 168, if that blows up and flattens out the pattern as the ECM main run suggests then it could end up in a dogs dinner of a pattern where we somehow draw the short straw again.

I’ll be extremely surprised if we go from this to this in 120 hours, yes it’s possible but these huge HP cells tend to be very stubborn in winter, I’d be more worried about the high pressure lingering in our locale than being blown away as the ECM shows

You can also see where the cold is coming from, low pressure to our south, N/NE primed with frigid air, would all depend how that low engages, for me the ECM flattens the pattern far too easily, but as I said, discount the ECM op at our peril!

The ECM blows that low up coming up the ESB like no other model really, taking this one with a pinch of salt but remembering the ECM for me is the top dog and we need to respect it.

Not very good at all? I’m genuinely astonished anyone can say that chart isn’t good… if you’re expecting 1963 charts at that stage then yes it’s not very good but if we got to that stage above on the 14th January I would be very happy with that. It’s all relative, not very good… I could post several NH profiles that are not very good and that’s definitely not one. Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4996713

Not very good at all? I’m genuinely astonished anyone can say that chart isn’t good… if you’re expecting 1963 charts at that stage then yes it’s not very good but if we got to that stage above on the 14th January I would be very happy with that. It’s all relative, not very good… I could post several NH profiles that are not very good and that’s definitely not one.

The issue is we need that low to engage the colder air really, most UK wide cold spells are brought in by this exact thing, hence fraught with danger. If we can get that HP south of Greenland some support via another ridge it’s just a matter of time till the cold gates flood open.

My advice to anyone of a nervous disposition would be to view the models up to 144/168 and anything after that is conjecture, if we can get 144 to t0 then it’s all to play for with that mad hemispheric profile

That high isn’t necessarily weak though, especially with that next jet of WAA heading up to reinforce the situation, doesn’t matter what the strength of the cut off heights is providing it does actually cut off. At the moment for me the biggest danger is that we don’t get a cut off high, in this situation our high pressure cell is almost too beefy for its own good.

I’m sorry but on what planet is that a bad chart? I’ve seen some truly abysmal charts over the last few winters and this absolutely is not one, plenty of chances from there if we got to that stage.

The thing is, heights weakening slightly isn’t a bad thing, sometimes a monster high isn’t always beneficial to us when it comes to advecting cold air our way, even a sausage of high pressure can produce if it lands in the right place

This kind of northern hemisphere picture at day 7, so fairly reliable, is quite astonishing for this time of year, this is one of those model watching periods where if you get too reactive on what you see after day 7 you will probably end up driving yourself doolally, everything in this chart indicates potential greatness. I’ve noticed on NW over the years you tend to get the posts tempering expectations and a bit more of a gloomy tone when a model run (ECM 12z) doesn’t quite end up where we had hoped, but thats part of the fun really… if we can’t get our hopes up at that day 7 chart then we probably never will. It’s the holy grail of cold chasing really.

Surely blowtorch mild is better than cool? I don’t know, but unless it’s cold enough to snow, being cold isn’t really for me Hadn’t looked at the models since yesterday and logged in this morning with some hope, but it appears things have gone even further the other way. More runs needed? No? Anyone?

Indeed, but it’s more the way it’s modelled the ESB and northern hemisphere profile, it’s performed dreadfully IMO

Remember when the GFS had that big GH…. Yeahhhhh, rubbish model, you would think it would model upstream issues better given it is an American model but alas not.