Cold hunt - models and chat

[Hammer]

980mb up channel or into NW France?

[Skullzrulerz]

I would love for this low just to go a bit more south so the far sw can get some fun

[Tim Bland]

3 minutes ago, bluearmy said:

You’ll have to forgive the southerners ...

not often they see a channel low showing within 72 hours!  

My snow line not adjusted  ........ stick with derby across to stoke and n Wales  for now. 

Is the last bit in relation to the low / snow line  on Thursday? What’s your gut feeling re northern extent Tuesday ? 

Edited January 26, 2019 by Tim Bland

[I remember Atlantic 252]

4 minutes ago, bluearmy said:

You’ll have to forgive the southerners ...

not often they see a channel low showing within 72 hours!  

My snow line not adjusted  ........ stick with derby across to stoke and n Wales  for now. 

14 miles south would be cool!

[Midlander]

Just now, I remember Atlantic 252 said:

14 miles south would be cool!

I thought he was talking about the northern extent of Tuesday low?

[Wilxy]

Is meteociel slow for anyone?

[Snipper]

26 minutes ago, bluearmy said:

About twenty past nine when icon takes the low through Paris .......

At least it might slow the riots a bit 

Edited January 26, 2019 by Snipper

[Tim Bland]

3 minutes ago, TomW said:

Is meteociel slow for anyone?

Yes, I’ve been hitting refresh on the 18z for 10 mins and it hasn’t even started for me

[Catacol]

The track of the low on Tuesday is likely to vary, but it is interesting that all 3 op runs from the big 3 have it running in pretty much the same line, from just off the SW tip of Ireland and down towards Brittany before perhaps following that classic channel path along the northern French coast. Normally we would see the GFS overblow the westerly momentum and have the system a bit too far north, with ECM tending to magnify the meriodional impact and perhaps project too far south. UKMO split the two and often more accurate. But what when all 3 are in line in terms of entry point?

Icon offers 3 hour snapshots so might be good to look at from this range. Early on Tuesday morning the low fills of the tip of Cornwall and brings rain to the SW ( for me...) 

but by lunchtime as it edges towards Dorset the winds will swing round to the SE and better DPs and uppers ought to develop on the northern flank. 

Uppers at this point too high for the SW, but for anywhere within the -4 line marginality may tip towards snow as drier air from the continent makes its present felt. By evening ICON has it sweeping into France and not moving much to the north at all as the colder uppers begin to pull in further - but how much precipitation may be left on that northern flank? 

By this stage and overnight the chances increase of anything in the air being snow - but those in the south would want the track to remain further north and not drop so far south. For those in the midlands precipitation is likely to be snow but the danger will be that the low tracks too far south = not a lot of precipitation.

End result - a fairly narrow band of the country may pick up the right combination of precipitation levels and uppers/dew points but those to the south see rain and those to the north potentially only a dusting.

HOWEVER this is one run, one interpretation. We will see how things develop. UKMO and ECM are better than ICON in keeping the system further north on its track and therefore giving those further east a decent chance. GFS is worst case scenario as the low plunges south and central/eastern parts are left out of the sweet spot.

Thursday/Friday also looking interesting...……My gut is telling me that Tuesday will not deliver what people are hoping for - all looking very marginal, but Thurs/Fri may be much better if the tendency for the atlantic track to drop south continues and we keep a bit more cold air in situ. 850s over France are not especially low for Tuesday, but they look a few degrees colder by Thursday which would be significant if correctly modelled.

Overall if we want a good snow event for a large number of members on here we are going to need upgrades. This kind of flat NW flow without a cold block to run into is a really difficult setup to get right for widespread snowfall. North and high ground always in better shape. I'm still on the hunt for a block that can bring uppers and DPs down before then looking at systems on the approach. This 144h chart from UKMO is the best in the medium range for this potential direction in a while...

[IDO]

Here you go:

[swfc]

 

4 minutes ago, Snipper said:

At least it might slow the riots a bit 

Good call by BA .think it's on course!!!lol

Edited January 26, 2019 by swfc

[Blizzardof82]

[MattStoke]

Not much change on the ICON.

Precipitation from the low goes through southern counties of England while a frontal system push east across Wales and the rest of England.

[SMU]

The ICON has taken a similar path to the UKMO where the low swims the channel then lifts NE towards Kent...

[Ben Sainsbury]

1 minute ago, MattStoke said:

Not much change on the ICON.

Precipitation from the low goes through southern counties of England while a frontal system push east across Wales and the rest of England.

A few frames later and the next slider doesn't seem to phased as much with the low to the North of the UK, hinting possibly at a slightly shallower low on Thursday.

[nick sussex]

I think a complication for the Channel Low for coastal areas is the flow .

So at the start that’s likely to be onshore from the se . It could be that it’s not until the low moves further east and the flow then moves towards a more ene to ne flow that colder dew points pulled sw from inland change that over to snow .

Theres not the depth of cold to avoid that marginality . Of course the track is still subject to change and if it does verify still a lot more runs needed .

Putting that aside at day 4 a much better shape to the next low moving se on the ICON 18 hrs . If that shortwave in the North Sea could get lost this would look very interesting .

Edited January 26, 2019 by nick sussex

[feb1991blizzard]

5 minutes ago, Steve Murr said:

The ICON has taken a similar path to the UKMO where the low swims the channel then lifts NE towards Kent...

A dumping for you? - elevation will be key.

[bluearmy]

23 minutes ago, Tim Bland said:

Is the last bit in relation to the low / snow line  on Thursday? What’s your gut feeling re northern extent Tuesday ? 

Thursday

20 minutes ago, AppleUK 123 said:

I thought he was talking about the northern extent of Tuesday low?

Nope - I won’t call on that. My instinct tells me that it won’t get north of the capital .....and i suspect it won’t be snowmageddon away from elevation in any case ...

[Duane S.]

Can’t help but think you may end up having to batten down the hatches yet @nick sussex 

These lows formed through RACY are often unusual in their tracking (deepening and not pulling NW) and intensity (severe) on the south western flanks

[Catacol]

1 minute ago, Steve Murr said:

The ICON has taken a similar path to the UKMO where the low swims the channel then lifts NE towards Kent...

And as we see every time this kind of event approaches the uppers are modelled differently to the previous run. Most recent ICON has better uppers = less marginality.

This will end up being a nowcast event right up to 6h....and I hope everyone's feet are firmly planted. Try and be pleasantly surprised if you get a good covering through Tuesday as this increases the fun. Don't be surprised if uppers are too high and the air in France not cold enough to modify it sufficiently to make the required difference. Some will be lucky I think, but I continue to think that more will miss out.

We will see. I would be delighted to be proven overly conservative....

[snowray]

Lovely ICON this evening, Thursdays low close to sliding on this run.

[feb1991blizzard]

Lovely Thursday - that's what i am banking on!!!!

Heavy continuous snowfall for hours.

[nick sussex]

1 minute ago, s4lancia said:

Can’t help but think you may end up having to batten down the hatches yet @nick sussex 

These lows formed through RACY are often unusual in their tracking (deepening and not pulling NW) and intensity (severe) on the south western flanks

At the moment I’m far enough south to avoid too much drama . I’d much rather though the low just shifted north to produce the goods re snow for you guys .

[Duane S.]

Just now, Catacol said:

And as we see every time this kind of event approaches the uppers are modelled differently to the previous run. Most recent ICON has better uppers = less marginality.

This will end up being a nowcast event right up to 6h....and I hope everyone's feet are firmly planted. Try and be pleasantly surprised if you get a good covering through Tuesday as this increases the fun. Don't be surprised if uppers are too high and the air in France not cold enough to modify it sufficiently to make the required difference. Some will be lucky I think, but I continue to think that more will miss out.

We will see. I would be delighted to be proven overly conservative....

Totally agree with all of that. Moreso my location for example. There will be a very narrow margin of error that makes anything other than a bit of backedge snow unlikely for me. But nice still to know there is a chance at least!

[Andy Bown]

Is there a chance of a week like early February 2009? Several 'sliders' brought snow events that briefly melted in between but also built up accumulations such that by the end of the week it was a significant amount. Admittedly that started on a Monday with an Easterly and powdery snow before the first 'slider' occurred.