Panayiotis

A very amateur illustration but this is my guess of what’s going to happen with the front

As it the band occludes and tilts, it should pick up intensity and slow down

I’ve been watching this too but most models show it getting sucked by the Welsh mountains before it gets to South Wales

I’m not sure on the stats or reliability of this model.

Harmonie has been the most consistent and bullish model leading up to this event, snowfall amounts shown here

Arome bullish on falling snow for most of Wales, pivot point close to Oxford on this run. Given that this event will affect most of the M4 I’m surprised Met still haven’t increased the weather warnings, disruption across a large part of the UK looks likely now.

Most models this morning are showing the band of precipitation moving through Wales, things haven’t really trended south which is great- HIRLAM is the only one which isnt interested and doesn’t make much of the system. It does look good for us in the South, best chance of the winter; wouldn’t be surprised to see an amber warning for the Valleys , possibly pushing south into Caerphilly/Cardiff/Newport

Dew points and 850hpa looking good for most of Wales bar the far west (as per my earlier post). Hopefully we get that precipitation in!

It’s a real tough one (as you might already know) especially as past events have these systems trend south nearer to the date. I do think any precipitation that does fall will be snow across most of Wales as dew points will be mainly below 0 from now until Sunday and 850hpa supports snowfall. Only the far west has the risk of precipitation turning more sleety as a band of warmer air (associated with the precipitation) gets squeezed across that area on Sunday morning. At this current time and it’s long shot even 36hrs before the event, I’m going for 1-3cm across South Wales, with higher ground seeing 3-10cm (Builth Wells being the most north). Note: Pivot point is around Hereford at the moment, but obviously this needs watching as this will be the difference between a slight covering for South Wales or something more substantial.

That shows precipitation intensity, the chart I’ve posted shows that 3-5cm of snowfall would accumulate if nothing else was considered

Arome bullish for falling snow for a lot of Wales !

Really? I think this winter so far has followed what is expected from a La Niña pattern with higher pressure in the mid- Atlantic and a meandering jet stream

Just a note before the 12z. That was one the quickest ‘turn-arounds’ across the models I’ve seen for a long while. From what looked like a decent cold spell (predicted by most models) has now turned into something uninspiring. Let’s see what translates over the next few days...

Has been showing it for the last few runs, on its own at the moment, hopefully something develops closer to the date

Can you post some evidence of this ?

Rain with some flakes here in Cardiff

Flurries here in Cardiff, keeping an eye on what’s over the midlands. Hoping the welsh mountains doesn’t suck out all the moisture by the time it gets here

This is what I’m concerned about. We are seeing great synoptics without the interference from a SSW. It will be very disappointing if the SSW ‘ruins’ our chances

You got to love model watching at the moment! We have northerlies, north-easterlies, easterlies, Atlantic highs, Icelandic highs, Scandi highs and Greenland highs, and the best is that’s this is all within 240hrs with all the westerly muck being forecast way out of range. Regards to the west based NAO being modelled; I actually prefer seeing it as from experience a *forecasted* w-NAO moves east closer to the actual date. I know the GFS hasn’t got the best name for itself, but it’s predicted this evolution quite well since I spotted it on the 14th.

Downgraded the cold yes but NH view is still great, let’s wait for the end of the run. Eyes on what’s happening to the north...

Rain with wet snow here in Cardiff

Different evolution to the 12z but we get the same result in the end- a pressure rise to the NE with winds off the continent. We dont see the toppling high over the Atlantic (like the 12z) ; more of a retreating one back to where it usually is (Azores). If you saw the first chart you wouldn’t be too impressed and one would think it’s a long way off cold but the flow buckles, with WAA to our north then moving heights over Scandinavia. As per my last post, it’s game on if we get energy underneath and the 18z did exactly that! One thing which has emerged from today is the theme to build heights to the NE and for us to be in a continental feed post Christmas time. I see it as quite bullish that the GFS wants to build pressure to the NE through different evolutions. It doesn’t know how we get the heights over Scandi but it’s signalling to us that pressure is likely to rise in that area after Christmas.

The GFS 12z run is something that I’ve been looking out for the last few days and it’s great to finally see it being modelled. Pressure rise to the west > northerly > north-easterly > high topples over > rise in pressure over Scandinavia > easterly The PV towards the end does ramp up which flattens the pattern but if we get energy underneath/weakened PV then it’s game on. Watching out for this evolution over the next few days...

It’s not a definite but like I said they have a tendency to shift east by a few hundred miles. We see countless notherlies forecast from the models in recent years only to end up with high pressure over us.

Hello all, back for the winter chase and we’ve got some interesting synoptics, very different to the last few years. From experience these patterns shift East closer to the actual date. This is what I’m looking for and would put the UK under a direct notherly/colder flow.