Model Output Discussion; into 2015

[IDO]

Yes more stormy weather than snowy. Though with a cold upper flow, as the cold uppers get ejected out of the US from D12, we do get some PM shots. Though for the S/SE/E not much consolation there. Another storm incoming (possibly) around D14-15 on the op and p: 

 

  

 

Latest EC32: 

  MattHugo81
The 06Z GFS by the 20th matches the broader pattern from the latest EC32 model well - http://t.co/s8Dqbqv4Ty - Colder weather poss.
1/6/15, 10:59 AM Edited January 6, 2015 by i'm dreaming of...

[nick sussex]

Disappointing output this morning, overall not enough amplitude upstream to deliver anything of note.

 

However there is still some confusion with the MJO signal, reading last nights NCEP update I expected to wake up to some better output:

 

This from their overview certainly doesn't tally with the ECM MJO forecast.

 

 Both dynamical model MJO index forecasts as well as statistical forecasts indicate a continued MJO signal during the next two weeks shifting eastward at varying speeds. 

 Based on the latest observations and several forecast tools, the MJO is forecast to remain active during the next two weeks with the enhanced convective phase shifting into the western and central Pacific. 

 

If it reaches the central Pacific that would at least take it towards phase 7.

 

I looked at the Australian update as the MJO has quite a large impact there and they suggest a divergence in the forecast.

 

It maybe that other factors might just mute out the signal even it does make progress eastwards, however until we get clarity on the MJO then I'd refrain from trusting the solutions in their later timeframes.

[Nick F]

Some might disagree but this feature of Northern jet and Azores heights has been a totally thorn in our sides and I can't wait for another solar minimum when the jet seems to like holidays down into Africa but the next solar cycle is in 2020 so suspect that things will decline in the next few years thus the return of the eye candy of the great winters.

 

 

It hasn't always been that solar maximums coincide with mild +AO/NAO winters. There was a solar max between 1978-1982 and that saw 2 notable winters of 78/79 and 1981/82. Conversely, the solar minimum between 1975 - 1977 didn't yield any cold winters. But the solar minimum does seem to help generally with getting our winters colder than average.

 

[Nick F]

While there's little to talk about it seems ...

 

NOAA look to make a significant investment in their supercomputer capacity:

 

http://www.noaanews.noaa.gov/stories2015/20150105_supercomputer.html

 

So we may see ECMWF play second fiddle to GFS is a few years?

[IDO]

It hasn't always been that solar maximums coincide with mild +AO/NAO winters. There was a solar max between 1978-1982 and that saw 2 notable winters of 78/79 and 1981/82. Conversely, the solar minimum between 1975 - 1977 didn't yield any cold winters. But the solar minimum does seem to help generally with getting our winters colder than average.

 

Solar-cycle-data.png

 

Yes research by Prof Lockwood highlights that there is an undeniable clear correlation between solar mins and cold in Europe:

 

"Statistically, we found a significant link between the occurrence of cold winters in the long CET record and solar activity. By "significant" we mean that there was only a five per cent chance that we were being fooled by a coincidence."

 

Source: http://www.carbonbrief.org/blog/2013/11/solar-activity-and-the-so-called-“little-ice-ageâ€/

 

No one is saying you cannot get cold when there isn't a solar min, however the chances (statistically) increase significantly when you are in one. So in the cycles there is a clear link so it is reasonable to assume when you have upticks within the long wave cycle that they will not be positive for cold spells. The last couple of months have had an increase in activity and although we cannot assume that has directly affected this winter it clearly would not have helped.

 

The GFS 06z control also has the D8 storm followed by a transient ridge: 

 

The GEFS still show variation on how the heights develop after D10: 

[SnowBallz]

The focus within the near-to-mid term is the omnipresent signal for deepening areas of low pressure to swing in; and, unfortunately, it's looking a little 'rinse and repeat' on that particular front.  All of the bases are loaded to fuel some powerful systems, and it therefore comes as to surprise to see such strength being advertised in resonance across NWP.

 

As has been previously covered, any significant stratospheric signal has rather diluted itself, therein resulting in a more mobile broad synoptic.  An important point to make here: the lack of any meaningful SSW does not preclude the chance for colder periods of weather to develop; indeed, even with SSW, neither is colder weather an absolute guarantee for our locale.

 

Severe weather is most definitely on the way, just not of cold origin.

[Captain Shortwave]

Unlike the calmer and milder GEM op, the control shows up this potential wind event for 9 days time just like the GFS.

 

Will need to wait a few more runs to see if there is model agreement on this. 

Edited January 6, 2015 by Captain shortwave

[bluearmy]

Haven't posted much because most of what I see on the nwp won't be well received on here.

Still plenty of chances for snowfall approaching mid month and thereafter but sustained cold seems out of reach.

I am looking at developments re the movement of the trop vortex mid month. We may be on a very slow drift towards a better NH profile for the last week of jan

[johnholmes]

Oh dear, 06z GFS operational continues to dash hopes, as 00/06z GFS P, for even a transient mid-lat high

 

Though wouldn't give up hope quite yet on the idea of a mid-latitude high or even a block after mid-month, but high latitude blocking is looking unlikely, perhaps for the rest of Jan given the persistence of the strong trop PV to the north .

 

Hints from GEFS and EPS of a pattern change upstream over N America from mid-month, as west coast ridge slides east to the east coast by Jan 19th (from -EPO to neutral/+ EPO). Not sure how this movement will affect downstream, as we are still stuck with a strongly +AO/NAO pattern with PV stuck to our north, it may entice a MLB, but perhaps not favourably for cold.

 

gfs_z500a_318.png

 

06z GFS op looks quite cold next week though, with the jet further south than 00z op, but that means any deep lows that develop over the Atlantic could cross over the UK rather than to the north, as the 06z alarmingly demonstrates.

 

That last chart you show Nick sums up looking at model outputs at pretty much any range just now. Compare that chart with the one link below from NOAA in their 8-14 last evening. Pretty similar in the west but quite different eastern Atlantic east. I wonder if NOAA charts may start to show this pattern although I am unsure of why the one you show has created such a ridge and trough over the UK/Europe-you any ideas? The NOAA chart does show the Atlantic into Europe contours beginning to open a little with some indication of -ve heights NE of the UK. In its 6-10 chart it has, as indeed have ECMWF-GFS, the idea of heights rising with weak ridging either in the east Greenland or Spitzbergen areas. This may be another version of the chart you show just beginning to develop that theme. Interesting to see how this plays out. As I am skiing from 18 January I certainly hope the chart you show is correct!

http://www.cpc.noaa.gov/products/predictions/814day/500mb.php

Edited January 6, 2015 by johnholmes

[Timmytour]

Interesting storm potential towards next weekend as others mention, but I wouldn't be surprised to see something a little nasty fly off that depression currently modelled to the NW of Scotland this weekend  and take a path south east.   Just a gut feeling that the Azores high will prove a little more flexible than appears and sag south to give way (before boucing back!). 



Either this weekend or nest weekend could end up provoking memories of that Burns days back in 1990


 

[knocker]

I'll limit any comment on yesterdays EC32 update to it doesn't show any light at the end of the tunnel.

[Dorsetbred]

**IMPORTANT**

 

There's only time for 8.4 attempts at the 240hr outlook before we get to SPRING.

[TEITS]

Looking at the SLP at various locations and this potential storm is rather worrying.

 

Devon

http://max.nwstatic.co.uk/ensimages/ens.20150106/06/prmslDevon.png

 

Aberdeen!

http://max.nwstatic.co.uk/ensimages/ens.20150106/06/prmslAberdeenshire.png

 

Not only does it have support but some have an even deeper LP.

[Jason M]

Just looked through the 06Z GEFS and they continue IMHO to water down prospects for the foreseeable. There still remain a few interesting runs but to my eye each of the last few suites have shown less promise than the set before. If this is repeated on the 12Z run I'd expect a predominantly zonal set right out to 384.

There is quite a lot of support for a brief colder shot at around day 10. I'd be wary of this though, as I suspect that nearer the time the flow will be a little flatter than shown by the GEFS. The reason for this being that the model tends to overplay transient North / Northwesterlies at distance. Maybe see if ECM tonight offers any support at day 10.

As someone pointed out earlier, sometimes at distance models play with a scenario, drop it and then bring it back with a vengeance. Lets hope its one of those times. Meanwhile The wait goes on and on and ........................

[Frosty.]

Apart from the mini cold spell some of us had during the festive season, overall the models look like they did last winter, albeit, not as wet as that washout but winds to rival it by the end of this week. Latest met office outlook into early Feb is for more of the same..I.e..mild, wet and windy and brighter, colder and showery interludes, for me to say anything positive would be very misleading...lol..this winter is rapidly sapping my enthusiasm.

[Blake]

 

Just to highlight the differences on the same model from one run to another for the same time. NAVGEM 0z and 6z for Monday morning. LP system off the north has disappeared and heights have begun to build over Greenland.

[Recretos]

Model topography of the new GFS:

   

 

A little bit of an improvement, looking at the old gfs, dont you agree?

[MPG]

I'll limit any comment on yesterdays EC32 update to it doesn't show any light at the end of the tunnel.

? You mean positive heights towards NE USA and Greenland, low pressure near the UK bringing colder weather? Or did you mean zonal?

[johnholmes]

Model topography of the new GFS:

   

 

A little bit of an improvement, looking at the old gfs, dont you agree?

 

 

quite impressive looking at the comparison for the UK

[knocker]

? You mean positive heights towards NE USA and Greenland, low pressure near the UK bringing colder weather? Or did you mean zonal?

 

Not exactly zonal but more or less.. For example the 29th anomaly shows Hudson Bay trough extending SE to NW of the UK and another trough Scandinavia. Ridge Siberia and zonal across the US. Surface analysis low Greenland /Iceland ( although of course this detail not relevant at this range) so much the same alterating pattern as now.

Edited January 6, 2015 by knocker

[legritter]

Still good possibilitys ,a fair chance that some of us could see some wintry weather turn up after our second low currently forecast to be very low pressure of 940 mb well to the north of mainland scotland this weekend .also hints of lower 850 mb temperatures turning up next week .not sure what to make of ECM 240HR CHART ,but hoping it can lead somewhere perhaps with tonights model runs .if theres not going to be any big players this winter regards SSW or siberian high etc we will just need the dice to fall right .but currently 6th january i,m still pretty confident of some real winter fun ,and as my post of yesterday still expect some change come mid month .but certainly not boring model watching more frustrating i realy feel like taking the razor to our azores high and just to remind the scandinavian high that it needs to buckle up and play ball ,and the jet stream to take a hike further south .but more runs are on the way today so lets wait pray and see .  

[Paul]

12z's just rolling out now, going to lock this and open a fresh thread in 2 mins..

 

Here's the new one

https://forum.netweather.tv/topic/82208-model-output-discussion-stormy-period-inbound/