Model Output Discussion 29th December - Into mid-Winter.

[Allseasons-Si]

52 minutes ago, Summer Sun said:

UKMO extended (15th) shows high-pressure edging back in from the west still chilly at the surface I would think certainly to start with

Seeing as we cannot see the NE of the BI suspect it would/hope it will look like SS

 

[Purga]

Here are the ECM ENS - pretty decent in my book with the Op on the milder side of the cold cluster again.

 

[Stephen_Mcr]

10 minutes ago, Steve Murr said:

Eyes down for the 18z - after a spectacular ECM mean alligned to the UKMO expect a significant GFS backtrack....

Hope so, would be remarkable even more so given the NOAA commentary. Expecting it to hold fire for now. 

[SMU]

Updated ECM 15day

A considerable swing to cold ( some may be surface cold )

12z first 00z second

mean maxima @0c for 6 days...

[snowbob]

18 minutes ago, Steve Murr said:

Eyes down for the 18z - after a spectacular ECM mean alligned to the UKMO expect a significant GFS backtrack....

Like I said in a post earlier gfs to my knowledge has always dropped the idea of cold, then backtracks in a true up and coming cold spell.

it nearly always over does the default Atlantic driven weather in this country, then realises the cold to the east is to strong.

if the ecm and ukmo had the Atlantic piling through I would be concerned but. there is no way the gfs is correct.

no science to back it up I'm afraid just age and experience.

the gfs will fall in line with ecm tonight or tomorrow's 0z

Edited January 8, 2017 by snowbob

[feb1991blizzard]

1 minute ago, Steve Murr said:

Updated ECM 15day

A considerable swing to cold ( some may be surface cold )

12z first 00z second

mean maxima @0c for 6 days...

Yes, I use these ones and a big swing back since the 0z.

[Allseasons-Si]

What would you make of this,a continental flow from the east midlands south?,looks like the ecm to me.

noaa 8-14

[snowflakey]

Not wanting to name anyone just in case I miss quote, but a couple of weeks ago someone said that you'll have to have the Meto on-board, when ECM & GFS were singing from the same song sheet. As it happened the Meto was on the money. is the situation the same this time round only its GFS out on its own, or is it that its preferable to have GFS on board and not a necessity.

Many thanks. Pete IOW

[Allseasons-Si]

1 minute ago, feb1991blizzard said:

Yes, I use these ones and a big swing back since the 0z.

And -25 showing on the table

[WINTRY WALES]

17 minutes ago, Steve Murr said:

Eyes down for the 18z - after a spectacular ECM mean alligned to the UKMO expect a significant GFS backtrack....

Fair play you don't half stick your neck on the block prior to model runs coming out with what you think and I take my hat off to you! 

[bluearmy]

Just now, Allseasons-si said:

And -25 showing on the table

Some -20c T2's in the south of holland and dp's below the-17 that caused IDO to become apoplectic earlier today. 

Certainly more easterly flow members present though the wind speeds seem fairly slack in general 

[bluearmy]

4 minutes ago, Allseasons-si said:

What would you make of this,a continental flow from the east midlands south?,looks like the ecm to me.

noaa 8-14

Wouldn't bother with that too much  as no eps input on a Sunday.  if the ens trend continues, expect it will look a bit more continental flow tomorrow

[Allseasons-Si]

9 minutes ago, bluearmy said:

Wouldn't bother with that too much  as no eps input on a Sunday.  if the ens trend continues, expect it will look a bit more continental flow tomorrow

But it has today's date on it blue!,but thanks anyway

looking at the wind direction on de built,GULP

and the dew points,bigger gulp,they was hovering around or just above the -5 line for the last few days,so a upgrade there.

Edited January 8, 2017 by Allseasons-si

[shotski]

7 minutes ago, bluearmy said:

Wouldn't bother with that too much  as no eps input on a Sunday.  if the ens trend continues, expect it will look a bit more continental flow tomorrow

By that I presume you mean no forecaster input on a Sunday ? 

[bluearmy]

Just now, shotski said:

By that I presume you mean no forecaster input on a Sunday ? 

Yes - it's straight naefs. With the discrepancies today, would have been interesting see how the forecaster would have weigted the varied output. 

[stewfox]

24 hour summary in brief (been out)

We have 26 pages last 24 hrs (always good for cold)

Given  GFS 12z is not on the same page as ECM & UKMO (at T144) and the implication this has regarding the up and coming weather. We MUST get full model agreement by T74 if we want a decent cold snap. If there no model agreement by T74 free prozac will be on offer. 

The pub run showing the "GFS 18z "' will be a all ticket affair.

All eyes will be on the "short wave" and where is it going to go. Hence its still FI.

Please no comments on the run before T3 and no 'winters over' by T6 should the GFS continues to disagree with UKMO & ECM.

IF GFS leans to UKMO and ECM then free drink will be available for 20 minutes.  

Supporting chart attached showing short wave in FI and potential out comes and the implication it will have for members..

 

Edited January 8, 2017 by stewfox

[shotski]

2 minutes ago, bluearmy said:

Yes - it's straight naefs. With the discrepancies today, would have been interesting see how the forecaster would have weigted the varied output. 

Ok thanks. 

Why is it we get the NOAA discussions on a Sunday but no human input in the anomaly charts ?

[bluearmy]

9 minutes ago, shotski said:

Ok thanks. 

Why is it we get the NOAA discussions on a Sunday but no human input in the anomaly charts ?

The anomoly charts are CLimate Prediction Centre who presumably don't work on a weekend.  

[damianslaw]

ECM continues to hold firm with the ridge having a much greater influence post imminent northerly, compared to GFS which flattens the flow very rapidly and leaves us under a broad westerly/southwesterly. The overall pattern of the last 2 months or so has been for the mid atlantic high to have the upper hand, kicking aide the chance of the atlantic riding easily through - this evening's ECM is much more plausible than the easterly outbreak, a sinking high scenario with low surface temps as we start next week. Won't be surprised to see GFS hold firm with its atlantic onslaught over coming runs- it the default GFS position, but the atlantic looks very weak going forward, and I suspect the form horse is for once again the ridge to develop over the country in situ bringing very similiar conditions to what we have experienced very start of Jan, i.e. cold frosty dry conditions interspersed with weak atlantic attacks sometimes from the SW and sometimes from the NW.

In the reliable all models agree on a 48 hr cold polar blast at least bringing snow showers to many places Thursday and Friday.

[weatherguy]

I would urge caution looking at de Bilt.  Yes any upgrades on temps there are promising, afterall that does signal the potential for an easterly, but fact is where there are such fine margins usually around how far west a blocking high will hold. I find this rather unhelpful when looking at the UK situation. 

Lets cross everything for UKMO.

Edited January 8, 2017 by weatherguy

[Allseasons-Si]

Ok so what we are looking for on the gfs 18z at 90 hrs is this,we want the gfs to show more amplification/trough disruption like the ukmo 12z showed at 96hrs(white circle) but not show what the majority of the models was showing at that same timeframe of developing a shortwave ahead of the main trough(red circle),here is the comparison

ukmo,gfs 12z at 96hrs

so we need more amplification into the states to force more WAA ahead of it but at the same time no more shortwave drama off the southern tip of greenland thank's.

[SMU]

GFS out to 72 & were closer.... the jet profiles over eastern US are more amplified-

has someone from NCEP fixed it finally...

[Ali1977]

Not much change at 78, thought we'd see it by then if a big back track was going to happen. 

[feb1991blizzard]

Just now, Ali1977 said:

Not much change at 78, thought we'd see it by then if a big back track was going to happen. 

The Jet is slightly more Amplified - only by the smallest of margins but the flow is more N of West  than the last run.

[Allseasons-Si]

Not much change  at 78 Steve,there is slightly more ridging and slightly a bit more of a gap between the lows though,small changes big impacts further down the line,maybe.