Model output discussion - the beast arrives

[BleakMidwinter]

Can anyone explain to me how this happens, or how often it happens?

I live in Telford (I promise, it IS model-related, not IMBYism!) and as you can see, we currently are in a Yellow Warning for snow this evening.

Except we're actually in TWO Yellow Warning areas, from almost-opposite directions. 

One Yellow warning says we may get snow from  the east/north-east. 

One Yellow Warning says we may get snow from the south-west. 

Surely that can't happen often, can it? Wouldn't the models normally have a firm idea of how to cope with opposing weather directions, especially given that they are different things, ie convective snow from the Easterly versus frontal snow from Storm Emma? It seems somehow very unlikely that they can't decide...

[Purga]

Yep, nice NE'ly BLAST next Saturday according to ECM

[ICE COLD]

 

4 minutes ago, Purga said:

Yep, nice NE'ly BLAST next Saturday according to ECM

Yep not really mild next week at all and getting colder towards the end . 

[ICE COLD]

15 minutes ago, Thunder Snow said:

What are the chances the cold spell will continue

I'm no expert mate but it will still be chilly next week going by the ECM . Cold enough for snow that's for someone with far better knowledge than me ?. Still frosts at night so still wintery . 

[Stuie]

Well, here is IMBY trend. It still doesn`t get above zero on the 850`s but does that mean a calm period or just awaiting a reload...

Edited March 1, 2018 by Stuie W

[Bob Lee]

1 hour ago, ICE COLD said:

Hope @Summer Sun is not looking at the ECM because here be having kittens again ?. Colder air coming back south ?

IT can be cold with sleet in May we all know that the short term shows it will get less cold than this period but a Heatwave is well off the menu... Famous last words lol... The question in this short term is how less cold will it get? 

[Derecho]

Swingometer updated again, seems to be a growing trend of less cold air advancing fairly northwards by Sunday on the GEFS. Still I think something like P7, which ejects a low pressure system east down the channel on saturday, is still a plausible outcome so I wouldn't rule it out just yet.

So maybe a temporary halt to the cold later on in the weekend, but for how long. I'd like this to carry on till mid march to give the beast the recognition it deserves. The synoptics have been remarkable as have the temperatures. Finally we get an epic snowfall to top it off (so it seems).

Hope people are enjoying the cold spell and are getting the snow they have been chasing for so long. 

[Summer Sun]

ECM 12z London mean has pretty good agreement for most of the run with the 850 mean generally between 0 and -3 before a drop to or just below -5 at the end

Central belt of Scotland 850's goe from around -12 today to around -6 by Sunday then -5 for a few days before holding steady again around -6

 

 

[Summer Sun]

26 minutes ago, Stuie W said:

Well, here is IMBY trend. It still doesn`t get above zero on the 850`s but does that mean a calm period or just awaiting a reload...

12z mean is a fraction higher albeit still below zero better agreement on this run until the end

 

[phil nw.]

32 minutes ago, Bob Lee said:

IT can be cold with sleet in May we all know that the short term shows it will get less cold than this period but a Heatwave is well off the menu... Famous last words lol... The question in this short term is how less cold will it get? 

A good question Bob.

Looking just at the gefs the further south the more noticeable any warm up will be but having said that next week doesn't look anything like Spring and further north over Scotland still close to freezing.

The ens 850's stay below zero nationwide for the next 7 days but the cyclonic pattern will contain less cold uppers as the current low will have mixed in some milder air from Biscay by early next week so we lose the really low 850's.

Having said that this complex low around the uk remains slow moving, cut off from the southerly tracking jet over Iberia.The winds will fall lighter and surface cold will tend to remain,although naturally without the Siberian feed daytime temperatures will lift somewhat affter the weekend.

The thing is though without the Atlantic jet heading this way really mild Atlantic air remains further south and is not driving north east over the uk which often happens with a full breakdown of an easterly cold spell when blocking finally gives way.

This is the day 7 GFS mean charts 

 

and 2 graphs for 2mt temperatures one for C.England and one for C.Scotland

 

shows temperatures still struggling to get above freezing north of the border for sometime to come so those snowfields likely to linger for days to come.

That upper trough modeled over the UK next week still contains a lot of quite cold air so no doubt we haven't seen the last of any snowfall especially up there after this weekend,maybe even further south depending on any movement back south of sufficiently colder air- which remains a possibility in this setup.

ECM ens out soon let's see what they say.

NB.I see SS has posted the ECM ens graph as i was typing-looks like cold is hanging around next week similar picture to above.

Edited March 1, 2018 by phil nw.

[Bob Lee]

2 minutes ago, phil nw. said:

A good question Bob.

Looking just at the gefs the further south the more noticeable any warm up will be but having said that next week doesn't look anything like Spring and further north over Scotland still close to freezing.

The ens 850's stay below zero nationwide for the next 7 days but the cyclonic pattern will contain less cold uppers as the current low will have mixed in some milder air from Biscay by early next week so we lose the really low 850's.

Having said that this complex low around the uk remains slow moving, cut off from the southerly tracking jet over Iberia.The winds will fall lighter and surface cold will tend to remain,although naturally without the Siberian feed daytime temperatures will lift somewhat affter the weekend.

The thing is though without the Atlantic jet heading this way really mild Atlantic air remains further south and is not driving north east over the uk which often happens with a full breakdown of an easterly cold spell when blocking finally gives way.

This is the day 7 GFS mean charts 

 

and 2 graphs for 2mt temperatures one for C.England and one for C.Scotland

 

shows temperatures still struggling to get above freezing north of the border for sometime to come so those snowfields likely to linger for days to come.

That upper trough modeled over the UK next week still contains a lot of quite cold air so no doubt we haven't seen the last of any snowfall especially up there after this weekend,maybe even further south depending on any movement back south of sufficiently colder air- which remains a possibility in this setup.

ECM ens out soon let's see what they say.

Thank you for superbly delivered non Ramping answer. Laying my cards on table I hate snow and ice so hope we have seen the back of this severe spell anything less intense is manageable 

[mb018538]

Actually looking ahead in the models and it would appear a return to more normal weather may be here before long.

Both the AO and NAO are rebounding, the zonal winds have returned to westerly, and by day 10 on the ecm we have our semi permanent features back in their usual spots - Azores high, Iceland low, PV wrapped back up over the North Pole. We manage to keep hold of the cold air for a while, so nothing warm just yet....but the slow move from winter to spring will be underway next week!

[Summer Sun]

12 minutes ago, mb018538 said:

Actually looking ahead in the models and it would appear a return to more normal weather may be here before long.

Both the AO and NAO are rebounding, the zonal winds have returned to westerly, and by day 10 on the ecm we have our semi permanent features back in their usual spots - Azores high, Iceland low, PV wrapped back up over the North Pole. We manage to keep hold of the cold air for a while, so nothing warm just yet....but the slow move from winter to spring will be underway next week!

Yes, hope springs eternal that something more akin to the season could begin to develop later next week (bit longer for the UK to feel the benefits of this) both the ECM Op and mean show the Azores high starting to move back into position after a short holiday

[PolarWarsaw]

21 minutes ago, mb018538 said:

Actually looking ahead in the models and it would appear a return to more normal weather may be here before long.

Both the AO and NAO are rebounding, the zonal winds have returned to westerly, and by day 10 on the ecm we have our semi permanent features back in their usual spots - Azores high, Iceland low, PV wrapped back up over the North Pole. We manage to keep hold of the cold air for a while, so nothing warm just yet....but the slow move from winter to spring will be underway next week!

As we saw at the end of March 2013....late season SSW's don't tend to favour ANY sort of mild spring, let alone one in early march. I suppose this year will be a learning curve, given we have just seen a record SSW. I wouldn't be surprised either way our weather tended, but my own personal thoughts are that it will be the very back end of April before jackets and jumpers can go back in the closed compartment of the wardrobe for a few months. 

It's been quite a dry winter too, certainly in different months. A nice wet summer would go down a treat, especially if it involved thunderstorms aplenty. I do fancy a very typical 'Polar squally showers' kind of spell throughout April also. Should be one for the convective cameras.

Edited March 1, 2018 by PolarWarsaw

[Snowy L]

22 minutes ago, mb018538 said:

Actually looking ahead in the models and it would appear a return to more normal weather may be here before long.

Both the AO and NAO are rebounding, the zonal winds have returned to westerly, and by day 10 on the ecm we have our semi permanent features back in their usual spots - Azores high, Iceland low, PV wrapped back up over the North Pole. We manage to keep hold of the cold air for a while, so nothing warm just yet....but the slow move from winter to spring will be underway next week!

If past composites are anything to go by we will see the most pronounced effects from the SSW some time at the end of March/early April (about 40-50 days after the SSW). Just because zonal winds have returned in the stratosphere it does not at all mean that mild zonal will dominate. Though yeah it is difficult to see where the next blocking, if any, would come from.

Edited March 1, 2018 by Snowy L

[PolarWarsaw]

2 minutes ago, Snowy L said:

If past composites are anything to go by we will see the most pronounced effects from the SSW some time at the end of March/early April (about 40-50 days after the SSW). Just because zonal winds have returned in the stratosphere it does not at all mean that mild zonal will dominate. Though yeah it is difficult to see where the next blocking, if any, would come from.

My thoughts precisely, lots of springs in SSW years have been cold, chilly and extended winter (albeit not cold enough for lowland snow). After a record breaking SSW I really do think it could be a very chilly spring, by spring standards (not snowy, before people start accusing me of working for the Express ). It will definitely be interesting to see if this spring follow suite. If it does, then you would have to build a case for a Jan/Feb SSW being linked to a very cold spring. 

Here is hoping anyway....It will be mild enough aplenty for all in the....you know....the next 8 out of 10 months of this year. We can all wait a few more weeks! 

[lassie23]

On 2/28/2018 at 16:01, Lynxus said:

Oh, Absolutely not, ..

Think I was fishing for someone to go " Hey you there! Looks at allllll these other models showing an eastward trend and colder uppers!! GFS too progressive etc etc etc"

Bored of convincing myself

Ecm was causing excitement yesterday, is that still the case today

[TEITS]

Nobody notice the fax for Tues chart!

[inghams85]

1 minute ago, TEITS said:

Nobody notice the fax for Tues chart!

I can never read these what does it show mate?

[mountain shadow]

7 minutes ago, inghams85 said:

I can never read these what does it show mate?

A continuation of a contintental feed of air. Not as cold or windy as now but no sign of spring and a continued risk of snow.

[feb1991blizzard]

-20c isotherm still hovering over Norway, would just take a better upstream pattern and we would be in business again.

 

[inghams85]

8 minutes ago, mountain shadow said:

A continuation of a contintental feed of air. Not as cold or windy as now but no sign of spring and a continued risk of snow.

Thank you ?

[lassie23]

9c by sunday in the south.......really? Which models are showing this?

[Lee Jones]

9 degrees in Norwich on Sunday according to the BBC. The warming is going to be more rapid than is being suggested by the charts maybe? Had pretty much everywhere above freezing. 4-5 Newcastle and Edinburgh. Wind arrows more southerly than south easterly. 

I don't trust them with regard to precipitation, I do with temps.

Edited March 1, 2018 by Lee Jones

[high ground birmingham]

Something to watch out for on the models btw...I am seeing a little potential for a snow event end of next week with a southerly tracking jet and cold air coming back south. Could be similar to Dec 10 2017 event.

Too far away I know but there is potential.