Model output discussion - proper cold spell inbound?

[Mucka]

@That ECM

Yes very much so. I was going to post many members now going for an Easterly flow shortly after mid month.

Let's hope this is the start of the models sniffing out the beast.

[Rayth]

6 minutes ago, Mucka said:

@That ECM

Yes very much so. I was going to post many members now going for an Easterly flow shortly after mid month.

Let's hope this is the start of the models sniffing out the beast.

Especially the control run in FL , can’t post an image at the moment but it’s eye candy ! 

[bradymk]

UKMO At 144. Those purples changing to lighter blues over the pole. Only 144 too but everything moving that bit further south and heights getting higher over the pole with time. Let’s see what ECM comes up with past 144

[Mucka]

It's a long way out and not much to go on but something like this could be very snowy (or wet)

Anyway continues the theme of better dig SE and lowering of heights into central Europe.

PS 

I see I said the Russian high further East when I meant West yet again. Let's just assume I'm going to get that wrong every time. 

Ageing is a terrible thing.

[Banbury]

GFS Control is truly bitter at the end 

[bluearmy]

The ecm nh profile shows the flow above our latitude hitting a brick wall by day 7.

how that plays out for us still uncertain 

seeing an aleutian tidge appear again now and it could be that the Atlantic sector stays the most active/mobile for longest

 

[ItNeverSnowsInWindsor]

I can’t see ecm t216-t240 being anywhere near close to verifying how it with ease gets rid of the cold air over Europe 

Edited February 6, 2018 by prolongedSnowLover

[That ECM]

1 hour ago, Raythan said:

Especially the control run in FL , can’t post an image at the moment but it’s eye candy ! 

FL, F1 or FI?  it's nice! Similar to p19

Edited February 6, 2018 by That ECM

[ITSY]

Yup, some lovely charts emerging in FI 

 

 

[Duane S.]

A nice variety of FI charts now beginning to show up in FI. I think we’d all take the Control run! 

The EC now showing the SSW to be at least a four day affair. Looking good.

Pin the tail on the donkey time soon though. In 6 days time that organised rotation of the strong upper vortex is going to be hit and hit hard.

Happy model watching days.

Edited February 6, 2018 by s4lancia

[Summer Sun]

GFS at t168 is mainly dry but cold UKMO extended is wet and windy

[winterof79]

Control same as yesterday dare I say with growing support

[Matthew.]

Isn’t there a worry this trough could stall here for a long time as the Atlantic transitions into stall mode. Aka west based NAO. The MJO, GWO, AAM trying to play ball but this trough being an absolute nuisance in the worst possible place. Anyway, enough from me, let’s hope the Ssw is strong enough to get enough momentum going to force the pattern Nw.

[winterof79]

2 minutes ago, Matthew. said:

Isn’t there a worry this trough could stall here for a long time as the Atlantic transitions into stall mode. Aka west based NAO. The MJO, GWO, AAM trying to play ball but this trough being an absolute nuisance in the worst possible place. Anyway, enough from me, let’s hope the Ssw is strong enough to get enough momentum going to force the pattern Nw.

Yes it may well fill in situ as height rises to our N/E build.

Meanwhile today is going to provide snow for quite a few.

[nick sussex]

The last February SSW did deliver a quick trop response. We’ve had some minor warmings in recent years but not a major one so this one doesn’t come around that often .

If I remember rightly the reversal there saw the outputs suddenly start correcting west but this wasn’t shown at the longer range.

Until the actual reversal occurs I’d be wary of anything shown. 

 

[Chesil View]

Couldn't agree more Nick any thing beyond 144 at the moment should be taken with a much bigger pinch of salt than normal. As S4L  suggested yesterday the change is likely to be abrupt and probably suddenly turn up in the shorter to mid term modelling rather than 300 plus. Wouldn't be at all surprised to see an abrupt changed come into that range by friday or the weekend.

Edited February 6, 2018 by Broadmayne blizzard

[bluearmy]

My view is that the SSW is no longer in the distance but within a week

i don’t see the nwp making any sudden changes within the next 10 days

i expect the staring flag to be waved around the 16/17th - how soon the cold bleeds to the mid lats unknown and does it affect us ??

[Snowmadsam]

I’m also biding my time and waiting until the warming is actually been and gone before actively looking for signs on charts as we don’t know the turn around time of the warming (qtr).

Models may shift patterns rapidly after warming takes place - for newbies to know. Take anything +144 (7 days) onwards with the biggest pinch of salt!

Nice surprise in Pembs this morning with big flakes falling out the sky!

[Seasonality]

38 minutes ago, nick sussex said:

The last February SSW did deliver a quick trop response. We’ve had some minor warmings in recent years but not a major one so this one doesn’t come around that often .

If I remember rightly the reversal there saw the outputs suddenly start correcting west but this wasn’t shown at the longer range.

Until the actual reversal occurs I’d be wary of anything shown. 

 

Which Feb SSW are you referring to Nick?

[johnholmes]

The 500 mb anomaly charts are certainly not yet showing any sight of the much talked about teleconnevtions bringing a serious cold spell in the 14-20 day period. That is what I think the story is.

Anyway the charts are below with a marked trough being the main player. Some differences in the 3 main models on precise positioning and depth etc but overall much the same sort of idea. String flow from fairly northern latitdues across the Atlantic into the UK and on into Europe. I suspect, in the period 6-14 days, there may be at least one quite deep surface low involved.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

[nick sussex]

1 minute ago, bluearmy said:

My view is that the SSW is no longer in the distance but within a week

i don’t see the nwp making any sudden changes within the next 10 days

i expect the staring flag to be waved around the 16/17th - how soon the cold bleeds to the mid lats unknown and does it affect us ??

Ok let’s have an internet bet! 

I think they will change. 

[Alexis]

4 hours ago, Mucka said:

Another marginal improvement on this mornings 00z by 144. Azores a little further SW and Russian high at tad further East.

Possibly of more interest is the embedded trough in V cold PM flow. It is just an illustration of what could happen at this range though

Likewise UKMO improved with trough digging SE and very cold PM flow.

UKMO looks worse to me. -7 instead of -8 temperatures at 850hpa and one step towards marginality.

[Met4Cast]

1 minute ago, Alexis said:

UKMO looks worse to me. -7 instead of -8 temperatures at 850hpa and one step towards marginality.

Really? 

I think once the SSW is underway, the models will begin to update to reflect that, I know they take predicted SSW's into account but nothing is as good as actual real life data being fed in. 

I think the ensembles for the first time ever are going to be useful here, they're probably going to pick trends out before the OPS really pick up on them, the blocking ones are more likely to be correct given the forecast SSW. 

[BLAST FROM THE PAST]

Certainly will be interesting but GFS 00z displays my ‘concerns’ well.  Block not in right place to bring ‘the cold blast’ .....not in Feb anyway.  Still we await the effects of the SSW.

From Midmonth target period, deep LP system attacking on WNW/ESE flow, then effect of building HP to E/NE forcing on trough either stalling it in place or hopefully forcing undercutting.

 

BFTP

Edited February 6, 2018 by BLAST FROM THE PAST

[tight isobar]

Looking like the point of change.

Taking gfs 'random- @180.

Anyone understansing the mechanics of modeling, will note that with n-hem signals (ssw-mjo phasing)..will have miss manage-b4 begining of decipher -align...

But we look 2 be at this stage of transfer and trop/strat developments are coming into range...

Expect to see big changes in these regions (snapshots)now in very near modeling...

And quite notable ones @that!!!.

As th pv comes under immense pressure .

With a rapid change in northern hemispheric synoptics.

10hpa(strat)..180hrs.

Edited February 6, 2018 by tight isobar