Model Output Discussions 18z 31/01/2016

[wishingforsnow]

And this model division is further proving that small details can have big implications on the eventual outcome for the weather 

[Sweatyman]

2 hours ago, weirpig said:

Midlands  wales north  snow on friday

Of course it will be rain by then!

[weather eater]

7 minutes ago, wishingforsnow said:

And this model division is further proving that small details can have big implications on the eventual outcome for the weather 

Small Island, small changes, big differences. The ECM is pretty similar to the GFS except the track is further north. Looking at it from that stand point, it is the ECM that is inching towards the GFS evolution.

Edited February 8, 2016 by weather eater

[nick sussex]

The ECM although redeeming itself between T144hrs and T168hrs is still the output I hope bites the dust.

The issue with waiting for it to play out its "less frustrate NW members for as long as possible" is more time for something else to go wrong.

Although it has a good set up at T120hrs over the ne USA the ships already sailed by then as its thrown too much deeper low heights east.

 

[snowice]

If there not singing of the same him sheet on 00z I'm going into hibernation!

[Guest]

This is my first post on here but I have been lurking in the background and studying models for many years. I’ve been obsessed by the weather since the age of 9 and the 1962-63 winter. I will make occasional posts on here. It has been fascinating watching the recent models for the short-term and so much to play for in the next few days. I’ll leave that discussion up to you guys for now and closely follow some of the expert analysis.

With all the excitement on marginal snow events and potentially some colder weather to come, I shall change the subject and draw your attention to the GFS 12z +240 hours. I hope the chart copies in properly. I know it is almost certainly not going to verify but it looks like the GFS expect the UK to break its all-time high pressure record! I would assume that the central pressure would be about 1054mb. The record is officially 1053.6mb (Aberdeen Observatory 31st January 1902). It was misquoted as 1054.7mb for many years but corrected in 2006 due to a mis-printed conversion from inches to millibars! With models struggling at +72 hours, this is most certainly distant F1. Even if we have some high pressure then, we all know that GFS are prone to exaggerate pressure extremes that far out.

Doc1.docx

[Gustywind]

I do wonder if this is yet another wild goose or snow chase! Even if GFS or UKMO are correct, which is tbc, will it actually be cold enough for widespread settling snow for lowland England?

Temps for end of week in central England are still progged to be 5 - 7c, way too mild for snow. All the various weather apps I have say rain away from high ground in northern England for Friday/Saturday, are they all wrong, based on ECM, or are we all seeing what we want to happen rather than what is currently forecasted to happen?

[nick sussex]

This really is a bit of a quandary because the ECM is the better solution past T144hrs compared to the GFS. The UKMO if I had to pick between the big 3 I'd grab now because this has the better chance of earlier snow events and a better chance past T144hrs of being similar to the ECM.

The frustration really is that everything is such a drama, can't some colder synoptics just be modelled, and  verify without all this trouble.

 

 

[chris55]

Some falling snow this winter would be nice lol. Not one single flake so far, so my hopes are for the slider to actually deliver. Though on Ians points west forecast the "S" word wasn't even mentioned.....so at present the MET are not seeing a snowy slider.

[wishingforsnow]

Just now, chris55 said:

Some falling snow this winter would be nice lol. Not one single flake so far, so my hopes are for the slider to actually deliver. Though on Ians points west forecast the "S" word wasn't even mentioned.....so at present the MET are not seeing a snowy slider.

With model disagreement even now at a few days out I don't see how they can mention snow when the models aren't sure themselves 

[syed2878]

@nick sussex  nick can u post the links to the mjo forecast discussions thanks.

[marksiwnc]

Just now, chris55 said:

Some falling snow this winter would be nice lol. Not one single flake so far, so my hopes are for the slider to actually deliver. Though on Ians points west forecast the "S" word wasn't even mentioned.....so at present the MET are not seeing a snowy slider.

None has been mentioned for the sw yet that's why. The BBC have said that there remains a risk of snow on the northern edge of the front.  It's a case of wait until that day I assume so. @fergieweather whats your take Ian?? 

[nick sussex]

5 minutes ago, Gustywind said:

I do wonder if this is yet another wild goose or snow chase! Even if GFS or UKMO are correct, which is tbc, will it actually be cold enough for widespread settling snow for lowland England?

Temps for end of week in central England are still progged to be 5 - 7c, way too mild for snow. All the various weather apps I have say rain away from high ground in northern England for Friday/Saturday, are they all wrong, based on ECM, or are we all seeing what we want to happen rather than what is currently forecasted to happen?

Weather APPS are a waste of time so don't worry about those. Theres a good chance of snow if the ECM is wrong. Theres enough cold air to the ne to engage low pressure tracking in towards the UK. But at the moment its impossible to say where these lows will track because of the model disagreements.

[Cheshire Freeze]

Low thickness, -4 uppers and lightish winds...hmmm if that's the worst output we're facing for the end of the week then we're laughing. A fairly high potential for a dumping across (mostly) higher ground of N England etc but also the chance of a surprise lower down

[nick sussex]

8 minutes ago, syed2878 said:

@nick sussex  nick can u post the links to the mjo forecast discussions thanks.

Do you mean the NCEP one? I'm still waiting for that to update, it should be out later this evening. The more in depth one is out tomorrow evening.

The link for tonights update is here, scroll down to expert discussions and the PDF  update.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml

On the same page you'll see Global Tropics Hazards and Benefits Outlook, link to that and this gives you a more in depth discussion which is updated tomorrow.

If you missed it Singularity did a great in depth post on the previous page. Currently theres a divergence between the ECM and GEFS.

 

[SMU]

Evening All

well it appears for the second month in succession the ECM is probably going to be pwned by the UKMO - only this time the GFS has joined the party as well

Stick with the UKMO - these similar circumstances to 2013 & Jan 16 saw UKMO come out on top

snow for wales & the midlands end if the week- possibly further north as well-

woeful performance again from the ECM expect it to fall into line with UKMO overnight...

 

S

Edited February 8, 2016 by Steve Murr

[Mucka]

On GFS Parallel 06z the lows weren't even far enough North to produce frontal snow for the South so there is pretty wide scope for their track

A lot depends on how much the shortwaves develop. The more thy develop the further North they will track as a rule.

Associated 850'5 with that run were cool/cold right the way through to 192

The variables should decrease tomorrow but the where and when of any snowfall may well go to T24

Edited February 8, 2016 by Mucka

[Frosty.]

The Fat lady isn't singing yet, indeed she has been escorted out of the building until further notice...she had been clearing her throat recently but things have changed! It's going to become colder and some of us will see snow. The Ecm 12z shows quite a cold plunge by the end of this week into the start of next week with further chilly weather beyond that and overall, having given up on winter last week, I'm pleasantly surprised to see wintry potential increasing in the near future!

[Mucka]

5 minutes ago, Steve Murr said:

Evening All

well it appears for the second month in succession the ECM is probably going to be pwned by the UKMO - only this time the GFS has joined the party as well

Stick with the UKMO - these similar circumstances to 2013 & Jan 16 saw UKMO come out on top

snow for wales & the midlands end if the week- possibly further north as well-

woeful performance again from the ECM expect it to fall into line with UKMO overnight...

 

S

It's only woeful if it is proved wrong Steve. 

There is enough spread in the ensembles to keep me on the fence for now though I do expect snow to fall somewhere come the end of the week.

[WINTRY WALES]

5 minutes ago, Steve Murr said:

Evening All

well it appears for the second month in succession the ECM is probably going to be pwned by the UKMO - only this time the GFS has joined the party as well

Stick with the UKMO - these similar circumstances to 2013 & Jan 16 saw UKMO come out on top

snow for wales & the midlands end if the week- possibly further north as well-

woeful performance again from the ECM expect it to fall into line with UKMO overnight...

 

S

Steve do you think this will be midlands and North Wales? Or Wales as a whole?

sorry to ask just sometimes Wales gets mentioned but the country rarely had a country wide hit...wondering if this is the case again 

cheers

[wishingforsnow]

9 minutes ago, Steve Murr said:

Evening All

well it appears for the second month in succession the ECM is probably going to be pwned by the UKMO - only this time the GFS has joined the party as well

Stick with the UKMO - these similar circumstances to 2013 & Jan 16 saw UKMO come out on top

snow for wales & the midlands end if the week- possibly further north as well-

woeful performance again from the ECM expect it to fall into line with UKMO overnight...

 

S

Welcome back Steve! Great encouragement

[SMU]

Well optimum would probably be central wales north but depending on track the south of wales at elevation could be at risk as well

 

s

[blizzard81]

7 minutes ago, Steve Murr said:

Evening All

well it appears for the second month in succession the ECM is probably going to be pwned by the UKMO - only this time the GFS has joined the party as well

Stick with the UKMO - these similar circumstances to 2013 & Jan 16 saw UKMO come out on top

snow for wales & the midlands end if the week- possibly further north as well-

woeful performance again from the ECM expect it to fall into line with UKMO overnight...

 

S

I disagree. The difference this time round is that the ecm was the first to model the wedge of heights to our north. It then consistently modelled it, along with sliders up until this morning's run. For some reason the ecm has dropped it compared to it's previous outputs. What worries me is the fact that the 12z run has gone the same way.

[Frosty.]

4 minutes ago, Steve Murr said:

Well optimum would probably be central wales north but depending on track the south of wales at elevation could be at risk as well

 

s

Exciting stuff, nice to be talking about snow being a possibility, for most of this winter it's been way, way too mild...we are really making progress now!

[wishingforsnow]

9 minutes ago, blizzard81 said:

I disagree. The difference this time round is that the ecm was the first to model the wedge of heights to our north. It then consistently modelled it, along with sliders up until this morning's run. For some reason the ecm has dropped it compared to it's previous outputs. What worries me is the fact that the 12z run has gone the same way.

That doesn't necessarily mean the ECM will be correct though