Model output discussion - Post SSW - Will it turn cold?

[mulzy]

Extended EPS - similar theme of the high heights retrogressing to Greenland (and beyond).  850s over the UK remaining cold.

Edited February 18, 2018 by mulzy

[Roadrunner]

Well I'm in the doghouse. The missus was trying to get 'romantic' this morning but I was too busy watching the ECM roll out. She now going garrety and thinks I'm cheating on her with a weather model. She just doesn't understand. Why did I marry this woman? 

 

In all seriousness, stunning stuff over the last 24 hours. In the words of GP - IT'S COMING. 

[winterof79]

2 minutes ago, snowblizzard said:

 

My Point being!

Strength of the sun and longer hours of daylight.

This is bound to have an adverse effect on depth of cold and snow melt, etc. 

There is no sun when it is snowing a blizzard

Edited February 18, 2018 by winterof79

[Smiler1709]

GEFS are not great this morning for deap cold, some struggle to bring in the easterly at all, others place the high latitude blocking to high and we're left with just a chilly SE breeze. I really want the ECM to be right and I know there are many more runs needed. Sitting on the fence here because it's been a shocking winter down here on the south coast and we really need the omega of runs to get us snow to finish winter. Looking forward to a day of ups and downs in the model thread.  

[Iceaxecrampon]

Classic battleground +216 though. 

[Chesil View]

8 minutes ago, Snowy L said:

Think bluearmy said something about this yesterday, GFS takes the high pressure too far North so we have annoying shortwaves deflecting the main cold and we become far more vulnerable to attacks from the Atlantic. We may have to wait longer for ECM and UKMO, but I would prefer them if it meant the Scandi high being closer to us.

Yes if we want an historic event then ecm route is way to go. GFS op has everything over in the south by 240.

[Man With Beard]

ECM op a slight outlier compared to its ensembles at D10 (how could it not be!) - but probably 50% of runs reach -10C 850s or less at some point.

[Eastnorthwest]

Morning all, models still struggling as usual  beyond 6 days gfs wants to suck up milder air by 10 bays time where as ec m  reloads the beast with eye freezing  lol  temps in the southeast ,

Gfs will change run to run let's hope ec m  doesn't 

[Weathizard]

2 minutes ago, Smiler1709 said:

GEFS are not great this morning for deap cold, some struggle to bring in the easterly at all, others place the high latitude blocking to high and we're left with just a chilly SE breeze. I really want the ECM to be right and I know there are many more runs needed. Sitting on the fence here because it's been a shocking winter down here on the south coast and we really need the omega of runs to get us snow to finish winter. Looking forward to a day of ups and downs in the model thread.  

Not great ensembles?  

[winterof79]

1 minute ago, Smiler1709 said:

GEFS are not great this morning for deap cold, some struggle to bring in the easterly at all, others place the high latitude blocking to high and we're left with just a chilly SE breeze. I really want the ECM to be right and I know there are many more runs needed. Sitting on the fence here because it's been a shocking winter down here on the south coast and we really need the omega of runs to get us snow to finish winter. Looking forward to a day of ups and downs in the model thread.  

Not forgetting UKMO

GEM

ICON

[kev238]

2 minutes ago, snowblizzard said:

Granted, but as soon as it stops snowing and clouds clear the warmth from the Sun in March melts snow very quickly even if the air temperature is close to freezing.

The chart you post whilst referring to spring snow is actually in February which is clearly - granted only just- in Winter!

[The PIT]

ECM drifting towards ukmo and gfs in not delivering the deep cold early on. Still cold mind you and good agreement. GFS develops a low pressure which manages to drift around against the air flow which looks plain wrong. GFS kills the cold off while ECM brings the deep freeze in lala land.

[LRD]

4 minutes ago, snowblizzard said:

My point being!

Strength of the sun and longer hours of daylight.

This is bound to have an adverse effect on depth of cold and snow melt, etc. 

Spring snow rarely sticks around for long.

2013 was only 5 years ago mate. Didn't have an adverse effcet then. If we were looking at polar maritime air then I'd agree with you. We're talking about severe Siberian ploar continental air. That can be very cold all the way until early April. What is being shown, by ECM especially, this morning is an extremely cold set up that would rival that March. If the weather is coming from the right direction it doesn't matter abut a strengthening sun

I think we should expect some ups and downs in the models and manage responses to every run with that in mind but I'm increasingly confident of seeing the wintriest (for low-lying southern England) week since 2013 from about Saturday/Sunday

[Seasonality]

38 minutes ago, MattStoke said:

ECM maximum day time temperatures for Tuesday 27th from this morning's run.

27'F is roughly -2'C.

That is 6:00pm UK time. The map is for central time in the US. Don't worry, I once made the same mistake myself.

[nick sussex]

Well that was a relief!

Its got to that point now were for UK coldies its nerve shredding  so as I'm a long suffering UK coldie by proxy very happy to see no major dramas this morning.

The ECM is fantastic because remember the flock of sheep analogy from last night.

The block builds in  a better position to usher in the deep cold to the UK.

The UKMO at T168hrs from what we can see looks great aswell.

[Smiler1709]

4 minutes ago, Weathizard said:

Not great ensembles?  

Yea certainly has put me back my feet this morning, hard not to be abit negative when there are many different solutions. I got a feeling this is going to be a lottery with the weather gods. GFS will hopefully correct itself on the 6z.

[winterof79]

Average ECM mean really 

GEFS   #SMILER1709

As its Sunday its always good to sing off the same Hymn sheet.

Edited February 18, 2018 by winterof79

[kold weather]

If the 00z ECM came off your going to get every single shower accumulate, there will be no melting with maxes below 0C just about everywhere. We are at the end of Feb, not the start of April!

The GFS also isn't remotely marginal,its just not very long lasting.

GFS ensembles are a worry though and just further highlight WHY an early easterly is NOT good, especially because it means the upper high is too far north. Your probably either going to get an early easterly down to say -10C and with a risk it totally misses...or a delayed easterly but much deeper and longer lasting cold. It would need perfection to get both, but that is still on the table as well.

PS, GFS ensembles are still good for a normal set-up...BUT this is EXCEPTIONAL set-up aloft, and what the GFS gives us is well, not exceptional but just a decent bog standard cold snap/spell on many of the ensemble runs. We could get so much more...many runs are likely not that snowy for the south as well, away from coasts. North is better.

 

Edited February 18, 2018 by kold weather

[LRD]

1 minute ago, Smiler1709 said:

Yea certainly has put me back my feet this morning, hard not to be abit negative when there are many different solutions. I got a feeling this is going to be a lottery with the weather gods. GFS will hopefully correct itself on the 6z.

I'm confident because what we know about the background drivers and the long wave pattern makes the output feel 'right'. Ordinarily, I'd be negative but not this time

[SLEETY]

1 minute ago, winterof79 said:

Average ECM mean really

Not a bad ensemble mean i guess

 

the gfs ensembles have been flip flopping for ages now ,is their any point to them

 

[Met4Cast]

15 minutes ago, Weathizard said:

Not great ensembles?  

Looks fine to me, with that amount of spread there's no telling what the way forward is, however there's more support for cold than there is for mild, anything beyond Feb 23rd is worth taking with a massive pinch of salt. GFS ensembles are useless at the best of times.

I'd be taking guidance in the mid-extended from the EPS rather than the GFS ensembles, EPS whilst can be fickle and have been during this week often tend to be more stable and pick out a clearer path forward.

The above is yesterdays 12z EPS, todays wont be out for a couple of hours but shows clear support for cold in the mid-extended range albeit with the usual large spread in the ext. 

For what it's worth, 00z EPS mean is absolutely solid, so expect an even better ensemble set than last night

Guys this isn't 2012, we've got a much, much better chance this time around.

Edited February 18, 2018 by Daniel Smith

[The PIT]

Some on here will remember the other beast of the east which marched down to T120 and then went tits up on all models on the next run. The cold down is the reliable time frame now so we are on but as to how cold is up in the air so to speak. As time goes on the power of the sun comes more into play as we had into spring but no guarantee the cold will be around then anyway.

When I was younger we used to have great heavy snow showers followed by spring sun going from white out to bright sunshine and rapid thaw in minutes.

[Smiler1709]

2 minutes ago, LRD said:

I'm confident because what we know about the background drivers and the long wave pattern makes the output feel 'right'. Ordinarily, I'd be negative but not this time

Hopefully mate, very limited knowledge in weather so purely commenting on what I see in the models this morning.

[captaincroc]

Obviously there is time for it to go tips up but what is softening the nerves is a lot of the building blocks are in high res now. Like the boulder getting the initial push down the hill... ?

[karlos1983]

Was everyone as nervous as I was as I squinted at my phone this morning (with mild hangover, thanks Gin ) 

what a relief and overall we can call that an upgrade across all models as they begin to align together! 

I much prefer the ECM root if I’m allowed to be picky, not a lover of the risky shortwave route the GFS takes us, purely because although snowy, longevity across the uk could become an issue, but that is being picky. About to go and stand and watch the lad play football, could feel very different next week!