Model Output Discussion - 14th Jan 12z Onwards

[BlueHedgehog074]

In terms of the type of Euro trough and how this could impact any cold advection into the UK:

 

Below are two examples, the first with the troughing more rounded and you can see the Scandi high sagging se on its eastern flank:

 

gensnh-3-1-192.png

 

After any initial cold the troughing will start drawing less cold 850's into the circulation from the Med.

 

Now in this example you can see the troughing is aligned more ene and stretches much further east, this cuts off any milder air from the Med and you also can tap into colder air:

 

gensnh-20-1-240.png

 

So what you want to look for in future outputs is the shape of the troughing and how far east it extends into eastern Europe.

That's handy to know. Well explained, too, with the arrows showing the direction of the flow's travel. Would agree that having the air source more originated from the North-East/East-North-East (especially if it's coming from Scandinavia or Siberia) could help draw in some very cold 850 hPa temperatures towards the UK and perhaps spark off some really heavy snow showers towards the East.

Quite like also how the Low Pressure system to the West of Iceland in that second chart looks as though it could disrupt and drop underneath the block to the North possibly giving a renewed Easterly flow for the UK.

[throwoff]

12z coming up soon, As a Kent local im very excited to see what happens.

[Snowy L]

Some areas could see many hours of snow if Tuesday's event comes off. The front is hitting us in such a way that some areas could easily see 10-15 hours of precipitation.

[Mucka]

In my experience I have seen my area (NW England) be predicted to be in the perfect spot in these slider setups for prolonged heavy snow while further South is a wintry mix but almost always the output is corrected SW and we often remain dry with heavy snowfall further South.

Southerners have been much less NIMBY than in recent years so fair play there but don't lose hope, this frontal snow event is way in FI as far as snowfall predictions go.

Unfortunately the nature of the setup means it is likely that some will be very happy in heavy snow while others are miserable in cold rain but it could just be some get snow and the rest remain mainly dry.

And remember this is only the initial slider event and areas that miss out here will very likely get other chances down the line.

It really is the type of setup where some unlucky sausage is going to see nothing ITBY yet snow East, west, North and South and wonder why the weather Gods hate them so.

Just so long as it isn't me! 

Edited January 15, 2015 by Mucka

[nick sussex]

That's handy to know. Well explained, too, with the arrows showing the direction of the flow's travel. Would agree that having the air source more originated from the North-East/East-North-East (especially if it's coming from Scandinavia or Siberia) could help draw in some very cold 850 hPa temperatures towards the UK and perhaps spark off some really heavy snow showers towards the East.

Quite like also how the Low Pressure system to the West of Iceland in that second chart looks as though it could disrupt and drop underneath the block to the North possibly giving a renewed Easterly flow for the UK.

To be honest the GEFS are a mixed bag with some taking longer to bring in an easterly, some hanging the troughing too far north and its not a surprise really because easterlies and the GEFS are not a match made in heaven. These generally only agree once much closer in terms of timeframe.

 

If you look at the upstream pattern the east Pacific ridge expected to build in and the flatter set up replaced by more amplitude, the Azores high often seen as the scurge of UK winters has an important role to play by amplifying off the eastern USA ahead of that upstream low, this gives time for the drop down slider low to separate from low heights over Greenland.

 

I think given the solid trend for that its very likely, the issue at the moment is really the slider low, and after that how long this takes to fill and where it centres as it does so, the troughing make up and orientation of the high over Scandi will determine the cold for the UK.

 

Anyway the fun and games starts soon, lets hope its more fun and less drama!

Edited January 15, 2015 by nick sussex

[SnowLover2010]

Some areas could see many hours of snow if Tuesday's event comes off. The front is hitting us in such a way that some areas could easily see 10-15 hours of precipitation.

 

Yes looking very promising for the North West in particular.

[SE Blizzards]

Don't know how reliable it is, but the first of the 12z's are out (GME) and it's a great start to the afternoon

 

 

[mulzy]

First 12z model out of the gate - the GME.

 

 

Good, very good but it's only the GME sadly....

 

Edit: SE Blizzards beat me to it!

Edited January 15, 2015 by mulzy

[phil nw.]

Just a quick heads up before the 12z runs- Chiono.has opened an Upcoming Cold Spell discussion thread here-

https://forum.netweather.tv/topic/82292-upcoming-cold-spell-discussion/#entry3120000

 

so if you want to just generally chew the fat on prospects over the next week or so rather than stick strictly to model discussion please post over there.

Ok cheers all.

[craigore]

Don't know how reliable it is, but the first of the 12z's are out (GME) and it's a great start to the afternoon

 

 

-8c 850 into KENT !!! Bank..

[nick sussex]

Don't know how reliable it is, but the first of the 12z's are out (GME) and it's a great start to the afternoon

 

 

That's a brilliant run, you'll see the energy is going se with the slider and the low is shallow. Whatever happens se transport is what we want to see, at this point if offered that GME I would be ecstatic if I was in the UK.

Edited January 15, 2015 by nick sussex

[fulham snow]

Hold onto your hats looks like snow falling or laying except the SW where just to warm at present depends if the low sinks south earlier,all to play for for us in the south East

[Downpour]

GME is a gem – let's hope the 12z GFS follows suit. Need to push that depression SE into the near continent to avoid a cold rain fest down here (which has always been a high risk scenario).

 

GFS o'clock. Hold on to your hats...

[fulham snow]

GME is a gem – let's hope the 12z GFS follows suit. Need to push that depression SE into the near continent to avoid a cold rain fest down here (which has always been a high risk scenario).

 

GFS o'clock. Hold on to your hats...

It is so close to being a blizzard for us in the South East but it is marginal if the front makes it to us before diving south so we end up with just cold.

[Hotspur62]

That's a brilliant run, you'll see the energy is going se with the slider and the low is shallow. Whatever happens se transport is what we want to see, at this point if offered that GEM I would be ecstatic if I was in the UK.

And the Heights up North look pretty good to get right alignment and thus establish a colder theme which will sustain snow to virtually all UK down the line!!  

[summer blizzard]

It is so close to being a blizzard for us in the South East but it is marginal if the front makes it to us before diving south so we end up with just cold.

To be deep enough to produce strong winds, you'd certainly see rain that far south.

You guys in the south want a shallow, flabby and slow moving low.

[nick sussex]

And the Heights up North look pretty good to get right alignment and thus establish a colder theme which will sustain snow to virtually all UK down the line!!  

Yes spot on, the GME is really great and we need to hope that the other models follow it.

Edited January 15, 2015 by nick sussex

[Snowmadsam]

To be deep enough to produce strong winds, you'd certainly see rain that far south.

You guys in the south want a shallow, flabby and slow moving low.

 

Correct, too deep and your warm sector gets wider...IF the GFS 12z holds some features further West it would benefit most parts of the UK as the warm sector would not pose as much of a threat.

[Hotspur62]

Correct, too deep and your warm sector gets wider...IF the GFS 12z holds some features further West it would benefit most parts of the UK as the warm sector would not pose as much of a threat.

Sorry, bit confused and just need explanation.I thought way GEM would be good for virtually all UK.Could you just explain "flabby low" and warm sectors as trying to get to grips with these terms.

 

Thanks

[karlos1983]

Correct, too deep and your warm sector gets wider...IF the GFS 12z holds some features further West it would benefit most parts of the UK as the warm sector would not pose as much of a threat.

 

But wouldn't that put the Easterly in jeopardy? 

[bluearmy]

Anyone link to the ecm stamps please

Also, how are the current stats looking for the para at day 5?

[Barry12]

The games begin on Saturday

 

 

Snow for the north and south if the GFS is correct.

Edited January 15, 2015 by Barry95

[nick sussex]

Sorry, bit confused and just need explanation.I thought way GEM would be good for virtually all UK.Could you just explain "flabby low" and warm sectors as trying to get to grips with these terms.

 

Thanks

In my excitement I called it the GEM which is the Candian model but the GME is the star so far. The shallower the low normally the smaller warm sector. The GME is superb, even if there was some warmer sector it would soon be pushed away se and any less cold conditions would be brief.

[snowking]

Anyone link to the ecm stamps please

Also, how are the current stats looking for the para at day 5?

I can't post the images alone up because I'm on my phone but this might help:

https://twitter.com/wsi_euroenergy/status/555754301394796544

Fairly evenly split clusters but I like the look of the strongest cluster days 11-15

SK

[No Balls Like Snow Balls]

Anyone link to the ecm stamps please

Also, how are the current stats looking for the para at day 5?

Day 5 stats