Winter Model Discussion 18Z 8/1/13. The hunt for cold (is closer).

[Snowly does it]

Reasons for cold spell pessimism - 06z GFS run goes against a protracted cold spell, with shortwave spoilers stopping WAA, Mid Atlantic ridge gets squashed into SWerlies, pattern shows no sign of breaking back to cold.

Shortwaves modelled within 'semi' reliable timeframe

Reasons for cold spell optimism - all the key models bar the recent GFS runs, ensemble average broadly supportive of coldish uppers, need to see where the 06z ensembles trend.

Reasons for not wanting to guess - 'record model uncertainty' - that phrase in and if itself should be warning against even cross model agreement outside of about T72-96

[nick sussex]

Hi Nick,

I've noticed you always go to the trouble of sharing this info with us, however for the thicker people on here (me!) would you be so kind as to put some more flesh on the bone with maybe a few words to translate what this info means for us?

Thank you.

Hi JP well if you look upstream its crucial how the energy is modelled around western Greenland. So that wave that NOAA are talking about starts off in BC and works its way across the USA, waiting to meet it is that low pressure anchored in the western Atlantic.

How these pieces of energy phase is pretty crucial to how much energy will spill east towards the UK, at the same time the GFS picks up some more energy and transports it east flattening the pattern,

The ECM separates the energy and brings just one low towards Greenland.

I'm going to do a bit more digging around upstream and then will put up some maps to show the differences.

[SMU]

They most certainly haven't ignored it but in 00z analysis for longer-term end by saying "NCEP-GFS considered unlikely and ECMWF preferred." Anyway, they won't consider 06z GFS in next update and only refer to midnight and midday runs.

& Just to take out that important bit- NOBODY inc the MET put ANY stock in the 06z...because its rubbish.S

[Iceaxecrampon]

Shovels at the ready for Worcestershire....

...and right along the M4 - good probability.

Monday - Reload for Western areas - temps at their coldest:

Ian

[Penicuikblizzard]

I seem to remember back in December GFS coming out milder on it's own and turned out to be right!! Maybe a new trend

[bradymk]

They most certainly haven't ignored it but in 00z analysis for longer-term end by saying "NCEP-GFS considered unlikely and ECMWF preferred." Anyway, they won't consider 06z GFS in next update and only refer to midnight and midday runs.

Encouraging, thanks for that Ian, nice to know (from a cold perspective) that they favour ECM over GFS today, well at the moment anyway!

[TEITS]

They most certainly haven't ignored it but in 00z analysis for longer-term end by saying "NCEP-GFS considered unlikely and ECMWF preferred." Anyway, they won't consider 06z GFS in next update and only refer to midnight and midday runs.

Sorry Mods if this is of topic but i've been longing to say this.

I can't tell you Ian how envious I am of you. My dream has always been to have a career in something I am passionate about and its clear Meteorology is more than just a job to you. I enjoy your contributions on this thread also love your forecasting style on TV. The last TV forecaster who in my opinion had a similar passion was a chap called Jim Bacon on Anglia weather. I wonder what happened to him?

[Iceberg]

Well Ive trawled though the GFS ENS at 06Z for T144 and only 2 runs support the ops run wrt the atlantic lows and total flatterning, most keep pressure much higher and the mean where the 980mb low in the atlantic at T144 is a full 30mb higher at 1010mb.

Seen enough to put that run in the very unlikely pile.

[GoonerGregg77]

I hope people can understand me on this one!?

When we are presented with a possible shortwave spoiler spinning out of Iceland, I'm sure with the Atlantic being blocked and the jet screaming south of the UK, this can't be a gospel to go by??

Would it be the case to assume that the GFS as with all models are possibly now looking at different scenarios after all agreeing on one major real possibility being the cold option and snow etc before actually reverting to a agreed scenario as depicted so beautifully yesterday? A biased view of course. Mumbo jumbo talk I know!

I'm sure things will turn around once we get closer to an outcome this weekend. If we can't predict what is going to be probable this weekend, how can we think that next week the Atlantic will scream in SW's!

All so very messy, but exciting as ever!

[Coast]

If anyone finds their post doesn't seem to be here any more, it is probably because it is more suited to this thread, where moaning is part of the reason for it existing:

http://forum.netweat...n-ramp-go-nuts/

A gentle hint, but hopefully some will take it?

Edited January 9, 2013 by Coast

[SMU]

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=168&code=11&mode=0&carte=0

IF the atlantic ridging fails then if the jet tracks suitably SE then this option is still WELL on the table

S

[Buzzit]

There are some very cold and snowy ensemble members : Example

[fergieweather]

Encouraging, thanks for that Ian, nice to know (from a cold perspective) that they favour ECM over GFS today, well at the moment anyway!

I'm told it's something to do with EC better at modelling/sampling synoptics from N/NE etc. Can't recall all the detail I was told yesterday about it.

[Snowly does it]

Add to my optimism grouping the latest MetO 6-15 dayer

[Frosty.]

My main concern with the ecm is that 24 hours ago it was showing pretty much what the gfs 06z is showing this morning with a fairly mild zonal outlook. It just goes to show that no matter how excited we get with the FI eye candy, the models can suddenly bring us crashing back down to earth with a mighty bump, on balance though, I still favour a cold outlook and we already have a cold weekend in the bag.

Edited January 9, 2013 by Frosty039

[Iceaxecrampon]

Atlantic murk pushing in Wednesday

Default......

So nothing prolonged? - not seen a flake here in Lancashire so far - off to visit my folks in Windermere on Saturday - enjoy it while you can people.

Ian

[Geordiesnow]

& Just to take out that important bit- NOBODY inc the MET put ANY stock in the 06z...because its rubbish.S

That what was not he was was quoted as Steve, he only said the updates are based on the 00Z and 12Z runs because presumingly they can compare it with the ECM and UKMO's runs.

The 06Z is a little disapointing for those looking in the medium term, yesteday had successful ridges, today's GFS 06Z run does not, I think we have to be careful and not read too much what the models actually say, its the usual saying of trends and that is an attempted ridge and looks like the PV is trying hard to head down into Scandinavia.

Still, looks like there will be a little bit of cold and even snow for some coming up BUT the detail is far from certain, how much of an easterly flow will we get and how much PPN will there be.

[snowking]

I must say if you look at the last 4 or 5 days, rather surprisingly in terms of operational runs the GFS has been something of a trendsetter, but when you see ensemble scatter to the extent that we have from both 0z's and now the 6z, it's a wonder why we are bothering to look past this weekend at this juncture.

Unfortunately after last nights cross model agreements longer term we return to yet more disagreement this morning. GFS currently on its own amongst the big 3, but should we be in the same position operationally come 0z tomorrow, concerns may start to be valid WRT longevity of cold.

In the meantime we should start seeing the weekends events coming into range of the NAE this evening, and then into the NMM tomorrow. GFS progs the traditional M4 coridoor type scenario, havnt had a chance to look at the full ECM det suite myself yet.

Then wintry showers scenario to the east into Sunday and Monday, with Ian's mentioned potential for something more significant into Monday further west.

Beyond that, just a lot of head scratching and not a lot of answers unfortunately

SK

[bradymk]

Well after a pretty dismal GFS 06z, some more optimism regarding Ian's post of UKMO favouring ECM due to it handling the N better and also the latest 6-15 outlook which suggest quite a strong easterly flow with central and eastern areas staying cold throughout and snow likely at lower levels moving westwards.

Edited January 9, 2013 by bradythemole

[Golden Hound]

Sorry Mods if this is of topic but i've been longing to say this.

I can't tell you Ian how envious I am of you. My dream has always been to have a career in something I am passionate about and its clear Meteorology is more than just a job to you. I enjoy your contributions on this thread also love your forecasting style on TV. The last TV forecaster who in my opinion had a similar passion was a chap called Jim Bacon on Anglia weather. I wonder what happened to him?

Jim Bacon runs a weather forecast business in Norwich called Weather Quest, he still broadcasts weather forecasts on BBC Radio Suffolk and BBC Look East TV.

[High Altitude]

Just to add a sense of realism, its practically all models VS the GFS here, all 144 charts

GFS

ECM

UKMO

GEM

BOM

JMA

CFS

NO support for GFS.

So often the GFS has been the only model to pick up on a cold signal and then slowly other models fall into line and pick up on the same trend only for the GFS to then drop it and we all scream outlier. Although this may be the case i've lost count of the times that it's been the first model to backtrack only for the others to follow suite. Having said that it normally goes from an ice age scenario at the height of its cold trend to a medieval warming type output in its next before finally settling on something inbetween - and for the UK this usally means a damp squib. Please don't be the case again. My emotions can't take much more of this!

[Frosty.]

Atlantic murk pushing in Wednesday

Default......

So nothing prolonged? - not seen a flake here in Lancashire so far - off to visit my folks in Windermere on Saturday - enjoy it while you can people.

Ian

Yes but it's only an op run, it's the polar opposite of the ecm 00z, perhaps a middle ground is more realistic?

[bluearmy]

quick scan through the gefs at t180 reveals that this isnt getting any easier to predict. exeter have come off the fence somewhat with their 15 dayer and i hope that isnt the 'kiss of death' !!

[Hammer]

GFS Ens at 06z t144 don't seem quite as progressive on cold being shunted away. In fact majority at first glance seem pretty good.

[ITSY]

less mild runs than yesterday with lots more around -10mark for a long time.

confidence building for cold IMO

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=276&y=27

Edited January 9, 2013 by ITSY