Model output discussion - mid-winter

[northwestsnow]

16 minutes ago, Steve Murr said:

Yes amplification of the pattern essentially means the jet / associated 500 MB heights with more North south emphasis as opposed to west east >

A direct NW polar flow over the UK in early Jan Bringing -6c uppers is almost a dead cert for snow for areas over 150 M in the NW ( lower that sightly Further North ) however south of Birmingham you are looking at a mix of rain sleet & snow- any moderation from the west & it’s rain all the way down here - you need more Northerly component for that here - say north of 320 degrees & uppers around -8c ....

So for some - looking great especially scotland & the usual high areas like Buxton etc etc plus the Irish hills - 

Other than that- just cold rain....

The system shown on the 168 UKMO is more often than not going to moderate the flow with a more Westerly ( even SW ) flow unless it stays very shallow - so that’s not a great chart if it’s snow your after...

Interesting post - thanks for that steve..

My view (inc many experiences) would be the height required would be 250m minimum in the NW-i'd say 300m is guaranteed a very wintry week..

We'll see how it goes- i fear the modification of the Irish sea on the western side of the Pennines - its been discussed in our thread - that irish sea is a killer for us..

 

Edited January 10, 2018 by northwestsnow

[bluearmy]

Eps this evening are certainly raising height anomolys in general to our west/south/north as we approach day 10 compared to recent output

 a lack of direction for the extended period and the gefs showed that just about any solution is feasible for the latter part of week 2 

 

[Walsall Wood Snow]

3 minutes ago, northwestsnow said:

Interesting post - thanks for that steve..

My view (inc many experiences) would be the height required would be 250m minimum in the NW-i'd say 300m is guaranteed a very wintry week..

We'll see how it goes- i fear the modification of the Irish sea on the western side of the Pennines - its been discussed in our thread - that irish sea is a killer for us..

 

I thought I heard Irish Sea temperatures are lower than normal this year?

[snowice]

3 minutes ago, Walsall Wood Snow said:

I thought I heard Irish Sea temperatures are lower than normal this year?

It's 10c at present

[Man With Beard]

3 minutes ago, karlos1983 said:

Presumably snow in the North West?

Looks like mainly high ground even there actually (200m plus) but a front coming in earlier might have snow on its front edge.

On the wind front, about 7 or 8 ecm ensembles (out of 51) also have severe winds, so not huge support for something as extreme as the op - but do check out member 48 on weather.us if you can. It brings I'd guess a category 2 equivalent storm through N Ireland and Scotland, with gusts above 100mph pretty much everywhere in this region, widely to 110/120 mph near coasts and maxing up to 140mph over N Ireland!!

 

[damianslaw]

Looking at the jetstream profile forecast and its an unusual one, a zonal flow but with the UK locked just about on the northern cold side permanently, the north in particular next week could see some notable snowfall, with no milder sectors, whereas further south the boundary of colder and slightly milder maritime air will sit. Longer term, no clear signal with the jet generally remaining southerly with signs of some mid atlantic height ridge development which suggests the trough could drop through the UK by next weekend sinking into Europe - then its all eyes on developments over the eastern seaboard - it does look probable the amplified flow we saw earlier in Dec could reestablish itself later in the month.

Models are now all in agreement that the trough will sink down over the UK by Monday - the weekend looks dry for many though with the trough not making real inroads only western parts. Meaning this week as a whole will be one of those very low diurnal type weeks temp wise - very average, maxes 3-7 degree range for many most of the time (today a bit of an exception), lows hovering between 0-3 degrees, very non-descript and quite a frustrating one given how we haven't been too far off a cold frosty sunny one had the high out east inched its way further westwards. This is turning into a very variable winter with no pattern holding particularly firm for any length of time, but neither any chance of anything especially noteworthy occuring so far be it of the wet, stormy mild variety, or the cold snow variety, but we are only just approaching the mid - juncture and the second half of the winter on average is far more likely to deliver the latter variety than the former, despite the strengthening rays of the sun, traditionally the atlantic does calm down somewhat and we are forced to look more towards the north and east.

[Captain Shortwave]

20 minutes ago, Man With Beard said:

Looks like mainly high ground even there actually (200m plus) but a front coming in earlier might have snow on its front edge.

On the wind front, about 7 or 8 ecm ensembles (out of 51) also have severe winds, so not huge support for something as extreme as the op - but do check out member 48 on weather.us if you can. It brings I'd guess a category 2 equivalent storm through N Ireland and Scotland, with gusts above 100mph pretty much everywhere in this region, widely to 110/120 mph near coasts and maxing up to 140mph over N Ireland!!

 

Giving the GFS a run for its money then. 

The theme still looks chilly next week with showers or longer spells of rain with sleet and snow at times. There is the risk of developments in the flow or more general secondary lows running along that elongated trough which could bring something signifcant. Overall the north and west could see some of the white stuff at times, for southern and eastern areas we might actually see the sun next week.

 

[Frosty.]

Tonight's Ecm 12z ensemble mean screams..or at least shouts cold zonality next week. ..I would expect some snowy weather at least across the north and especially on hills but that doesn't preclude some wintry ppn further south either, a wintry feeling spell next week at the very least!

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=6

 

all  i say hr 132 looking good cant wait to see the pub  run in  the morning!!!

[Weegaz]

4 minutes ago, Captain Shortwave said:

Giving the GFS a run for its money then. 

The theme still looks chilly next week with showers or longer spells of rain with sleet and snow at times. There is the risk of developments in the flow or more general secondary lows running along that elongated trough which could bring something signifcant. Overall the north and west could see some of the white stuff at times, for southern and eastern areas we might actually see the sun next week.

 

Could see a lot of the white stuff where i’m based captain, midlands could see abit to based on below

[January Snowstorm]

Hoping for some small upgrades for my location on the 18z 

The uppers are the wrong side of marginal.....you really need lower to give something more worthwhile. It's a hills and sleet affair at the moment 

[Day 10]

1 hour ago, snowice said:

It's 10c at present

It's currently 7.2c at Crosby a little below average and a lot lower than Dec. Were did you get your reading of 10c?

[Newberryone]

There’s no disguising the fact that Day 10 of tonight’s Ecm is rather unpalatable to say the least. Only crumb of comfort is it's considerably outside the reliable timeframe. If you think the forum’s relatively quiet tonight, there would certainly be no threat of a server overload should that dreaded Azores high take up residence post day 10. 

[SLEETY]

One thing that hasn’t dominated our winter yet has been the Azores High,but STILL it’s been a fairly unremarkable winter.Maybe the pub run can  cheer everyone up with a mega cold run.

Edited January 10, 2018 by SLEETY

[feb1991blizzard]

Pattern further North already on 18z - downgrade coming on longjevity and uppers - more specifically how far south any decent uppers get.

[winterof79]

Cold ensembles from 12z really with snow for some

Edited January 10, 2018 by winterof79

[john mac]

3 minutes ago, feb1991blizzard said:

Pattern further North already on 18z - downgrade coming on longjevity and uppers - more specifically how far south any decent uppers get.

Pub run could have been on a bender 

 

[frosty ground]

7 minutes ago, feb1991blizzard said:

Pattern further North already on 18z - downgrade coming on longjevity and uppers - more specifically how far south any decent uppers get.

When you posted this the GFS was out to about 84 hours and 48 hours away from the first signs of the colder weather. 

 

The differene at 102 is almost non existent 

Edited January 10, 2018 by frosty ground

[ACCOUNT DELETED]

1 hour ago, snowice said:

It's 10c at present

Sea temperature in the Bristol Channel is slightly lower than the last few January's Swansea is about 8C that's more like mid February. 7C is normally the coldest here and occurs late Feb or early March

[Man With Beard]

5 minutes ago, Newberryone said:

There’s no disguising the fact that Day 10 of tonight’s Ecm is rather unpalatable to say the least. Only crumb of comfort is it's considerably outside the reliable timeframe. If you think the forum’s relatively quiet tonight, there would certainly be no threat of a server overload should that dreaded Azores high take up residence post day 10. 

Should just comment that a temporary nose of the Azores High has been a very common theme on the ECM ensembles between 19th and 21st January ... but the ensembles are equally keen to ditch it shortly after.

Well actually anything goes after the 21st atm - it's like there's something coming up that has the models totally bamboozled. Yesterday's and this morning's extended EPS had no idea where it was going, and looks like tonight's will be the same. Only thing I can fathom between D12-D15 is that a Euro ridge is a little more likely than a Euro trough, and MLB slightly more likely than HLB. But it's very unclear.

[snowice]

11 minutes ago, frosty ground said:

When you posted this the GFS was out to about 84 hours and 48 hours away from the first signs of the colder weather. 

Yes snow showing up in Ireland 126 hrs on pub run looks cold and blustery? 

Edited January 10, 2018 by snowice

[feb1991blizzard]

8 minutes ago, frosty ground said:

When you posted this the GFS was out to about 84 hours and 48 hours away from the first signs of the colder weather. 

 

The differene at 102 is almost non existent 

Tiny differences will make all the difference at this point, it was clearly further North when I posted and it clearly is at 120 still, when you are in an already marginal situation (particularly those midlands southwards), the last thing you want is it moving northwards, plus the trough isn't elongating quite as much as on the 12z.

[feb1991blizzard]

Compare 12z and 18z at 132, -6c and -4c isotherms clearly 50-100 miles further North.

EDIT : I don't think the 100 miles will make a huge difference to the synoptic setup after this PM incursion but the more elongated the trough is - the better.

Edited January 10, 2018 by feb1991blizzard

[Snowmadsam]

2 minutes ago, feb1991blizzard said:

Tiny differences will make all the difference at this point, it was clearly further North when I posted and it clearly is at 120 still, when you are in an already marginal situation (particularly those midlands southwards), the last thing you want is it moving northwards, plus the trough isn't elongating quite as much as on the 12z.

The only time we will know it’s true position is when it happens. Models are a SIMULATION, not a reality. They are to guide, not give an answer 

[frosty ground]

2 minutes ago, feb1991blizzard said:

Compare 12z and 18z at 132, -6c and -4c isotherms clearly 50-100 miles further North.

Wow thats a nats private parts differene

looks awful