Model Output Discussions 06z 04/11/16

[DOdo]

Matt Hugo has just tweeted  a very seasonal outlookl

[ITSY]

12GEFS show virtually half following the control with most straddling -5 uppers for low res, with the other half virtually following the op without any such cold. ECM should be interesting....

Edited November 23, 2016 by ITSY

[nick sussex]

It wouldn't be the same without shortwave gate rearing its head at the start of winter! US forecasters often use this to describe shortwave lows tracking across the USA.

The longwave pattern is for example where you see for example ridge/trough set up. The shortwave is exactly what it says on the tin, they're the smaller features and travel through the longwave.

Shortwaves can be anything from just kinks in the flow or can develop into deepening low pressure. In the UK some of the worst winds often happen when for example a shortwave develops at the base of the main trough deepens rapidly and runs east into the UK.

I hope that explains it better, the UKMO won't really talk about shortwaves , they just tend to talk low or high pressure.

The reason we tend to talk about shortwaves a lot in here is because they're often important with trough disruption where we see them sliding under high pressure and supporting say for example a Scandi high.

Edited November 23, 2016 by nick sussex

[snowice]

5 minutes ago, nick sussex said:

It wouldn't be the same without shortwave gate rearing its head at the start of winter! US forecasters often use this to describe shortwave lows tracking across the USA.

The longwave pattern is for example where you see for example ridge/trough set up. The shortwave is exactly what it says on the tin, they're the smaller features and travel through the longwave.

Shortwaves can be anything from just kinks in the flow or can develop into deepening low pressure. In the UK some of the worst winds often happen when for example a shortwave develops at the base of the main trough deepens rapidly and runs east into the UK.

I hope that explains it better, the UKMO won't really talk about shortwaves , they just tend to talk low or high pressure 

 

Lets hope we can wave bye bye to the shortwave! Ecm hopefully will have us all by 7pm lol!

Quote

 

 

[fergieweather]

Reason UKMO won't talk about shortwave features at T+168 is because that sort of nuance is utterly unreliable at that range. We have enough trouble accurately forecasting shortwave troughs at T+12, let alone at a range where we're much more focused on ensemble forecasting, not small-scale vagaries of deterministic output run-to-run. 

[feb1991blizzard]

11 minutes ago, nick sussex said:

It wouldn't be the same without shortwave gate rearing its head at the start of winter! US forecasters often use this to describe shortwave lows tracking across the USA.

The longwave pattern is for example where you see for example ridge/trough set up. The shortwave is exactly what it says on the tin, they're the smaller features and travel through the longwave.

Shortwaves can be anything from just kinks in the flow or can develop into deepening low pressure. In the UK some of the worst winds often happen when for example a shortwave develops at the base of the main trough deepens rapidly and runs east into the UK.

I hope that explains it better, the UKMO won't really talk about shortwaves , they just tend to talk low or high pressure.

The reason we tend to talk about shortwaves a lot in here is because they're often important with trough disruption where we see them sliding under high pressure and supporting say for example a Scandi high.

[chrisbell-nottheweatherman]

9 minutes ago, nick sussex said:

It wouldn't be the same without shortwave gate rearing its head at the start of winter! US forecasters often use this to describe shortwave lows tracking across the USA.

The longwave pattern is for example where you see for example ridge/trough set up. The shortwave is exactly what it says on the tin, they're the smaller features and travel through the longwave.

Shortwaves can be anything from just kinks in the flow or can develop into deepening low pressure. In the UK some of the worst winds often happen when for example a shortwave develops at the base of the main trough deepens rapidly and runs east into the UK.

I hope that explains it better, the UKMO won't really talk about shortwaves , they just tend to talk low or high pressure.

The reason we tend to talk about shortwaves a lot in here is because they're often important with trough disruption where we see them sliding under high pressure and supporting say for example a Scandi high.

In the Learner's Guides section, there's a guide on long vs. short waves (https://www.netweather.tv/forum/topic/78216-wave-12-activity/) that discusses the mid-level charts as being a superposition of different wave functions - Rossby waves (wave numbers between 1 and 4) being standing long waves, the next function being medium waves (individual cyclonic and anticyclonic cells with a net westerly movement) and then shortwaves which are either very small attatched lows or deviations in the circulation of a parent low.

Getting back OT, I cannot see much wrong with todays output for those who want to see colder conditions; surely general trends are the most important past around T+120?

[I remember Atlantic 252]

shortwave? looks like one, from great 90's, brought me a very good snow event out of nothing, completely unforecast by bbc

[nick sussex]

5 minutes ago, fergieweather said:

Reason UKMO won't talk about shortwave features at T+168 is because that sort of nuance is utterly unreliable at that range. We have enough trouble accurately forecasting shortwave troughs at T+12, let alone at a range where we're much more focused on ensemble forecasting, not small-scale vagaries of deterministic output run-to-run.

I understand why the UKMO doesn't  talk about them. The general public are used to low and high pressure, its only us model anoraks in here who talk about them! lol

[Mucka]

ECM 144 not dissimilar to UKMO, just a tad less amplified upstream

[Jonan92]

ECM seems to be better than this morning and yesterday

 

Yesterday

 

Today

 

Much closer to GFS

[feb1991blizzard]

Another epic fail from the GFS, but for reverse reasons this time!!!

[nick sussex]

ECM underwhelmed rating 9/10! No PV over Greenland, amplified upstream pattern and yet still the forces that be are determined to deliver zip in terms of interest.

The shortwave in the Atlantic is in the worst location and it all goes downhill after that. Another poor effort from the ECM.

Not content with the previous 216hrs of tedium the ECM at T240hrs delivers the worst chart of the season so far. Time to get the Lapland brochures out!

Edited November 23, 2016 by nick sussex

[Guest]

4 minutes ago, feb1991blizzard said:

Another epic fail from the GFS, but for reverse reasons this time!!!

Can you explain please? thanks

[SMU]

Is this the new ECM ?

looks like someone at ECMWF programming has hit the 'Northern heights delete' button...

To be fair it beat the GFS the other day when it was ridging to Greenland - lets hope its 1-1 come tomorrow eve-

At least ECM cold @ 240 trying to build a scandi High--

S

 

[feb1991blizzard]

3 minutes ago, More Snow said:

Can you explain please? thanks

The GFS has shown a stonking Northerly today which we know now due to the Met Office text update not mentioning any uncertainty, will not verify, where as its usually the GFS that fails by over doing the strength of the Atlantic and consequently models mild outlier solutuons (usually with Scandi high potential in the offering)

Edited November 23, 2016 by feb1991blizzard

[Frosty.]

High pressure generally bosses the Ecm 12z, only briefly muscled out of the way later in the run before building east again, it drifts around and this would affect cloud amounts and frost / fog distribution but it looks like a generally fine benign spell lasting quite a number of days across most of the uk.

Edited November 23, 2016 by Frosty.

[Guest]

1 minute ago, feb1991blizzard said:

The GFS has shown a stonking Northerly today which we know now due to the Met Office text update not mentioning any uncertainty, will not verify, where as its usually the GFS that fails by over doing the strength of the Atlantic and consequently models mild outlier solutuons (usually with Scandi highs)

Ahh i see.... thank you for the explanation...

[swfc]

So non the wiser then!!! guess its a suck and see up to 7 days then sniff the dirt and throw it wind.tbh ecm looks way to flat imo.The jet of the esb does throw a spanner in the works with the spoiler low but i cant see what why or or ecm loses the nhp blocking???

[Scandinavian High.]

5 minutes ago, Steve Murr said:

Is this the new ECM ?

looks like someone at ECMWF programming has hit the 'Northern heights delete' button...

To be fair it beat the GFS the other day when it was ridging to Greenland - lets hope its 1-1 come tomorrow eve-

At least ECM cold @ 240 trying to build a scandi High--

S

 

Metoffice mentioned there is a possibility of high pressure building  to the north east . 

[blizzard81]

2 minutes ago, abbie123 said:

Metoffice mentioned there is a possibility of high pressure building  to the north east . 

I must admit, that did catch my eye on today's meto update. For all the talk on here of a mid atlantic block and general blocking to our north west as Dec progresses, the meto mention high pressure especially to the north & east. Mmmm!

[bluearmy]

I think the high to the north east was glosea for mid Dec rather than early dec

the extended eps have consistently failed to support such a feature 

[phil nw.]

Another set of runs which-if looking for cold -could have quite easily delivered more with better Atlantic ridging.

The Canadian height anomalies continue but we just can't yet see any solid Atlantic blocking at higher latitudes-indeed it's the Azores high that is the spoiler forcing the nw-se pattern of polar incursions just too far east into Scandinavia and C/E.Europe.

We can see this happening as early as day 5

with the models showing further pulses of cold heading that way later in the runs.

The gefs graph for C.England

The above is the 2m temperatures and rainfall forecasts so quite dry and chilly with high pressure never far away.

Edited November 23, 2016 by phil nw.

[blizzard81]

9 minutes ago, bluearmy said:

 

A word of advice for anybody who thinks the ecm day 10 chart looks bad for cold. Look at it on wetterzentrale. You will see what I mean when you look. It looks so much better. Most of the time I look at the northern hemisphere on meteociel but there are some situations when the wetterzentrale charts give a wider perspective. This was not meant to be a response to BA.

Edited November 23, 2016 by blizzard81

[mountain shadow]

30 minutes ago, nick sussex said:

ECM underwhelmed rating 9/10! No PV over Greenland, amplified upstream pattern and yet still the forces that be are determined to deliver zip in terms of interest.

 

I just cannot fathom how we cannot get proper heights into Greenland given the complete absence of the Polar Vortex in that area, mind boggling.