Model output discussion - deep cold inbound?

[sheikhy]

Any news on the 96 hour chart from the 06z ecm?!

[Man With Beard]

4 minutes ago, mountain shadow said:

I'm confused. 

How can that be showing South Westerlies with such low heights pretty much over us?  Cluster 1

The 510dm is just to the North and the whole UK and Ireland in sub 528dm.

Genuinely confused. 

The cluster charts do not show thicknesses - they show 500mb pressure only. For thicknesses, you need a comparison of 1000mb and 500mb charts.

On cluster 1, for instance, a fairly deep trough is shown just to the NW. It's similar to this chart on the GFScontrol, as far as the the N Atlantic area (though slightly shallower low on the cluster 1)

 

[ItNeverSnowsInWindsor]

Looks like a snowy Sunday coming up for the South East!

[Scandinavian High.]

3 minutes ago, steveinsussex said:

Fergie believes the breakdown will be wed-thurs next week 

Yes just seen that low coming up hit south west England possibility snow . I don’t think they will push further north then  go across southern  England snow risks..

[mulzy]

8 minutes ago, sheikhy said:

Any news on the 96 hour chart from the 06z ecm?!

Very similar to the 0z run - margins here and there but basically the same.

[sheikhy]

Just now, mulzy said:

Very similar to the 0z run - margins here and there but basically the same.

Nice one mulzeh!!!!

[Weather of Mass Disruption]

1 hour ago, Froze were the Days said:

I'd be surprised if the cold lasts much beyond next week...deep cold on our shores rarely lasts beyond 5 days-week, but apparently the SSW warmings continue and yes with such warmth over southern Europe and deep cold to the north there's going to be a big dumping somewhere! Bring it to East Anglia I say

It’s definitely hard but not impossible, such a set up, like we have approaching and in what is still in the heart of winter could easily be extended in duration. Those in the 80s lasted for a least 2 weeks (as I recall), the really lengthy ones like 47 and 63 are for sure, a lot rarer, but again not impossible. I would say, in a world of extremes, we have as much chance seeing this becoming a historical spell of winter weather as we do it lasting just a week for the former 

[CameronWS]

Would we be more likely to see upgrades or downgrades from here?

Looking forward to this, good luck to everyone! Despite being in Scotland I haven’t had a single cm lying here since Feb/March 2018 so pretty hopeful

[Battleground Snow]

MJO update,

No real changes, maybe GEFS hinting a move towards phase 8 late on, it's quite remarkable how long it's forecast to stay in the western Pacific.

With la Nina in the weak range now and stratospheric developments still ongoing, the ECM weeklies continue to show high lat blocking probably has some merit, there might be Atlantic incursions at times, but the NH profile should remain conducive to colder episodes well into March

Edited February 3, 2021 by Battleground Snow

[Don]

56 minutes ago, MATTWOLVES said:

One big difference about that failed cold snap Don was the fact the Met office were never on board with it. I remember a met expert being asked on social media why they were not mentioning it...and his replie...was give it time and they will be!! Needless to say they never did,and they was proven correct.

Was this the 2019 spell Matt as I'm sure the Metoffice were on board with the December 2012 non event?  As for next week, I can't get excited as it looks dicey for my location and could end up as virtually a non event.  Not saying this will be the case but too early to get excited.  Too much of a high risk scenario with the Atlantic!  However, if I lived further north  and east I would be very close to celebrating now!

[Malarky]

Looking at the models, should we be concerned about those lows firing in from the Atlantic as the cold is only just starting to get going? Or is the consensus that they're being over blown?

[bluearmy]

Just now, Malarky said:

Looking at the models, should we be concerned about those lows firing in from the Atlantic as the cold is only just starting to get going? Or is the consensus that they're being over blown?

Yes and who knows .....

[joggs]

Just now, Malarky said:

Looking at the models, should we be concerned about those lows firing in from the Atlantic as the cold is only just starting to get going? Or is the consensus that they're being over blown?

I think they're been overblown. There might be a breakdown in the sw but majority I feel will stay cold. If they slide reinforces the easterlies and or cold.

[Stu_London]

1 minute ago, Malarky said:

Looking at the models, should we be concerned about those lows firing in from the Atlantic as the cold is only just starting to get going? Or is the consensus that they're being over blown?

These are still in FI - as we know verification of FI charts is poor.

[jimbo36]

Anyone know why the ECMWF High Res 0z won't go beyond 000 on WXCHARTS?

Can it be viewed elsewhere?

[DAVE_ALLEN]

3 minutes ago, Malarky said:

Looking at the models, should we be concerned about those lows firing in from the Atlantic as the cold is only just starting to get going? Or is the consensus that they're being over blown?

They may well bring a breakdown to more marginal, rain/sleet/snow for the south, and theres a good 48-72 hours of healthy snow opportunities for the South before that arrives. The cold could well extend for a day or two beyond that further north with an awful more lot snow.

 

[Don]

1 hour ago, kold weather said:

PS- nice rain event for the SE on Monday on the 00z ECM fwiw....again why its important that the low is placed perfectly otherwise that will happen.

Do you not mean the 6Z?

[SqueakheartLW]

A rather decent update for the 06z GFS after the upgrades that began with yesterday's 18z. The peak of the cold on the 06z comes in at 144 hours away. The average charts for that timeframe are below

The average easterly is still maintained and that is one thing at least that the GFS has maintained recently even if the depth of cold has varied throughout. The latest 850hpa temperature average at 144 hours away comes in at a decent -9.9 which is -6.5 below the long term mean and is in fact the 2nd coldest 850hpa temperature I have featured in my updates, only the 00z GFS from Mon 1st Feb was colder at -10.4. When looking at the 850hpa temperature chart Scunthorpe is so close to the -10 isotherm. The anomaly chart is showing a deepening of the blue colours again and further distance between the UK and that dreaded Europe mild area.

Here is the 06z GFS ensemble chart for Scunthorpe

As you can see a several day cold period coming up but I am going to show the average coldest run and average mildest run from within this time period where the ensemble mean is at or below -5 at 850hpa to see how different they are and what could potentially happen if we end up at the least cold or coldest end of the scale

Mildest Run between +90 hours and +198 hours     Member 10

+90 hours     850hpa temp -3.8

+102 hours     850hpa temp -6.4

+114 hours     850hpa temp -3.4

+126 hours     850hpa temp -5.6

+138 hours     850hpa temp -5.4

+150 hours     850hpa temp -5.0

+162 hours     850hpa temp -5.9

+174 hours     850hpa temp -2.3

+186 hours     850hpa temp -1.1

+198 hours     850hpa temp -2.5

Overall Average 850hpa Temperature For Member 10 between 90 and 198 hours= -4.27

Maximum 850hpa Temperature for Member 10 between 90 and 198 hours = -1.10

Minimum 850hpa Temperature for Member 10 between 90 and 198 hours = -6.40

 

Coldest Run between +90 hours and +198 hours     Member 29

+90 hours     850hpa temp -7.8

+102 hours     850hpa temp -11.7

+114 hours     850hpa temp -13.9

+126 hours     850hpa temp -12.0

+138 hours     850hpa temp -13.1

+150 hours     850hpa temp -14.8

+162 hours     850hpa temp -13.2

+174 hours     850hpa temp -12.6

+186 hours     850hpa temp -14.4

+198 hours     850hpa temp -11.8

Overall Average 850hpa Temperature For Member 29 between 90 and 198 hours= -12.62

Maximum 850hpa Temperature for Member 29 between 90 and 198 hours = -7.80

Minimum 850hpa Temperature for Member 29 between 90 and 198 hours = -14.80

 

Mildest chart from the period between 90 and 198 hours away

Member 28     +186 hours     850hpa temp 2.6

Coldest chart from the period between 90 and 198 hours away

Member 23     +192 hours     850hpa temp -15.6

 

Mildest doom and gloom chart from the whole of the 06z GFS

Member 24     +282 hours     850hpa temp 8.9

Coldest fantasy chart from the whole of the 06z GFS

Member 23     +192 hours     850hpa temp -15.6

[Bricriu]

32 minutes ago, Scandinavian High. said:

Yes just seen that low coming up hit south west England possibility snow . I don’t think they will push further north then  go across southern  England snow risks..

He did suggest that some models might be too progressive in bringing the milder air back in. Their in house models seems confident the milder air won't  win out throughout the UK. So maybe less cold in the south with some significant snowfall to be had before a milder turn. It would be great if the GFS control from last night turned out to be correct!

[Youcan'tbecirrus]

51 minutes ago, phil nw. said:

The cold spell now within sight and good agreement at day 5 between the ukmo op and the ecm mean on the 850's coming right down the country.

The low moving just far enough off the e.anglian coast so that the stiff easterly flow affects pretty much everywhere .

Current charts will not yet have a handle of snowfall detail wrt amounts and locations. but i think it's reasonable to expect snow showers coming from the east with every chance of more organised streamers of disturbances being picked up nearer the time.

Now the battleground is further south hopefully all snow loving members will have a chance to join in the fun.

Slightly confused. Didn't the low move out of the south east into France ? The low you mention off east anglian coast is another low or have I lost the plot... which is very likely? Just looking to be educated. All very fascinating that's for sure.     

[ancientsolar]

1 minute ago, Bricriu said:

He did suggest that some models might be too progressive in bringing the milder air back in. Their in house models seems confident the milder air won't  win out throughout the UK. So maybe less cold in the south with some significant snowfall to be had before a milder turn. It would be great if the GFS control from last night turned out to be correct!

That means a battle ground! If we could somehow get the whole country snowy before that battle.. perhaps it would give us an upper edge... and that I guess.. largely depends on if any showers can be blown in far enough on the Easterly wind, a bit of a convergence with some troughs would be perfect

[MATTWOLVES 3]

14 minutes ago, Don said:

Was this the 2019 spell Matt as I'm sure the Metoffice were on board with the December 2012 non event?  As for next week, I can't get excited as it looks dicey for my location and could end up as virtually a non event.  Not saying this will be the case but too early to get excited.  Too much of a high risk scenario with the Atlantic!  However, if I lived further north  and east I would be very close to celebrating now!

Yes Don,it was that failed ESTLY event when the icon backtracked and all the other models followed suite that very evening..that event was January im sure of it. The high risk high reward scenarios that Atlantic fronts bring would be where we get that significant snowfall risk..But and its a big but,how much inroads would they make against the cold block!! Entrenched cold air is notoriously hard to shift when embedded.If this scenario were to play out we would be looking towards Wales and the Midlands for potential High impact conditions,but it hard to say if this scenario will play out this way,as per the met,the fronts may only make limited inroads into the SW,which would put those areas at risk,especially on the Northern edge..The possibilities are endless and its only me having a speculative punt which I love to do. We get the cold in first and then anythings possible,basically expect the unexpected at short notice.

[Singularity]

I'd rather not look so far ahead now but with respect to around Wednesday onward, that's where we have to consider typical model bias and bear in mind that this can cause all models and entire ensemble suites to paint the wrong picture.

In other words, in the 6-10 day range, strong cross-model agreement can be misleading in certain setups. Most notably, ones where the polar jet is well south of normal and trying to return back north.

If there's one model correction we've seen a lot of this winter, its toward troughs having a harder time progressing northeast. Remember when the charts for this week had warm sectors affecting the entire UK by Mon/Tue with only fleeting, transient snow to be had away from the mountains of Scotland?

[BLAST FROM THE PAST]

2 hours ago, feb1991blizzard said:

Hey???  -  I would put my life on it that you will get more snow than me, and Kent will get absolutely battered.

Look at my emojis , it is tongue in cheek.  I know it’s superb as I’ve been saying.  Let’s hope it continues 

BFTP

Edited February 3, 2021 by BLAST FROM THE PAST

[Bricriu]

9 minutes ago, ancientsolar said:

That means a battle ground! If we could somehow get the whole country snowy before that battle.. perhaps it would give us an upper edge... and that I guess.. largely depends on if any showers can be blown in far enough on the Easterly wind, a bit of a convergence with some troughs would be perfect

Yep. The more colder upper air we can get entrenched the better for any frontal situations