North West England Regional Discussion 14/01/13, 12z Onwards

[The Northern Ramper]

If the Gfs verifies (and at t72 probability is rising) then we will be digging ourselves out at some point on Sunday.

Copious amounts of snow and strong winds.

My mistake, we get hit again Sunday afternoon!!

[Cheshire Freeze]

Just one word for this GFS run.

HAPPEN.

A proper snowstorm Ian. Something we haven't seen in a long time.

[The Northern Ramper]

Just one word for this GFS run.

HAPPEN.

I would sacrifice the rest of winter for an event like the one shown tonight.

[pip22]

Its getting colder out here and frost is forming already here. Freezing here in terms of temperature.

Edited January 15, 2013 by Fresh_Prince_Of_Leyland

[k19]

Great charts for the region today but quite literally just on the right side of the 850's needed. With any luck there won't be any movement eastwards.

Edited January 15, 2013 by kev19

[weatherobsuk]

Going to be a bit snowy heading to the Pub on Friday still a wee dram or two should suffice as a celebratory toast if all goes to plan model-consensus wise.

[Jan]

12z certainly looks the part but will it deliver? if it's still showing on thursday morning I might start believing

[cfallon]

Yup holding out for thurs for my ramping! Great to see Ian ramping! :-)

[Snow free zone]

Anyone with a bit more knowledge ..... 6 hrs since the last run, how can there be this much variance between the output from this model ? seems way OTT to me how the thing swings from run to run. I know we are looking (relativley speaking) at unusual synoptics here but really the changes are quite incredible within a 6hr timeframe.

I suppose that said it can quite easily swing back the other way.

[jam2010]

My weather app has changed to snow on Thursday and Friday and Sunday. Where has the Thursday one come from?

[Interitus]

The 12z GFS is astonishing for the region. Hypothetically, 15-20cm quite widely should something like that come to pass

Precipitation accumulations between now and midnight Saturday - nearly all in this region being snow on Friday/Saturday.

http://91.121.16.5/m...8-777.GIF?15-12

[cfallon]

My weather app has changed to snow on Thursday and Friday and Sunday. Where has the Thursday one come from?

Mine too?!

[Interitus]

My weather app has changed to snow on Thursday and Friday and Sunday. Where has the Thursday one come from?

There is another front over the west coast of Ireland now, which may brush our area on Thursday, but will probably be fairly weak when it gets here.

[Ian Brown]

Anyone with a bit more knowledge ..... 6 hrs since the last run, how can there be this much variance between the output from this model ? seems way OTT to me how the thing swings from run to run. I know we are looking (relativley speaking) at unusual synoptics here but really the changes are quite incredible within a 6hr timeframe.

I suppose that said it can quite easily swing back the other way.

Each of the 4 GFS runs use different starting data sets. The 06z and 18z are generally considered the less reliable, and over recent days the 06z has been most progressive with the Atlantic (although I've not seen every 18z).

[SP1986]

I suspect the GFS is hugely exaggerating everything, from the snow totals to the temperatures.

That said, I suspect the GFS has massively undestimated the temperatures tonight. Already -0.3C and dropping still at a rate of -5C/hr. I suspect the -3C forecast will look a bit silly at dawn tomorrow.

[UV-RAY]

Firstly what an absolutely barnstorming GFS and UKMO, if this was to verify it would surpass February 1996 even. But before we go all orgasmic on this lets remember just how many times we have been led down the garden path, but then to find we are in the wrong ruddy garden. Tomorrows output will hopefully give us some clarity for Friday and beyond, now I'm off to sacrifice a chicken to the weather gods.

Edited January 15, 2013 by Sceptical Inquirer

[MrSunshine]

I expect there will be a correction south. Based on that I would say midlands, south to get heavy snow falls apart from extreme southwest which would get rain.

From the MOD thread just now, sounds like a little hopecasting from a southerner going on here! lol

[The Northern Ramper]

I have to say I don't think uppers will be an issue, the precipitation missing us to the South remains my main concern.

[Rnewbs]

Should I be going to tesco and buying a snow shovel? Probably feel a bit ridiculous taking one to the checkout. Hopefully i'll have the last laugh if this actually happens

[SP1986]

I wonder if there is any data corruption in the 12z? The GFS had temperatures at -6C which fell to -16C in the space of 2 hours.. as far as I know even with snow cover this is bordering on impossible in our climate. Furthermore, the day after it rebounds to +2C.. I suspect that's an error rather than a modelling accuracy. Of course if there is errors in the temperature output, potentially there could be errors in precipitation too..

If not errors then a simple over-reading of signals by the GFS

Edited January 15, 2013 by SP1986

[snowdrifter]

Only just been able to check the latest. To add to Ian great one word summary:

PLEASE HAPPEN...

[Ian Brown]

I have to say I don't think uppers will be an issue, the precipitation missing us to the South remains my main concern.

That is the only possible problem, correction South and Westwards.

[Maz]

I have to say I don't think uppers will be an issue, the precipitation missing us to the South remains my main concern.

That's my concern too. The GFS has strengthend the cold block to the NE, but still has the Atlantic fronts pushing across the whole UK, which doesn't quite add up.

In the last few years such systems slipped through Wales, West Midlands, South Central England and didn't get to us. However the "attacking" low pressure is further north then in those cases, so just maybe.

[snowdrifter]

Ian Fergusson (v highly respected m/o & points west weather chap if you don't know) on model thread just said

"But UKMO-GM and GFS 12z's favoured as it stands. Very tricky, very high stakes down at Ops Centre."

Every little (big?) helps...

Edited January 15, 2013 by snowdrifter

[The Northern Ramper]

It's coming from a different angle to the usual so I am hoping the models have a better grasp on it.