Cold Snap, T0-180Hours Only

cherryghost

EDIT: Double post, as above, marginal for tonight and tomorrow, Wednesday and Thursday seems our best bet right now.

Meanwhile there's a couple of pertubations that I know some of us would definitely be interested in :P

jo06555

So the whole of Europe gets destroyed in cold while poor little Ireland gets the mild spell from the east is that the right way I'm looking at those charts ?

Musicman2000

jo06555 wrote: »

So the whole of Europe gets destroyed in cold while poor little Ireland gets the mild spell from the east is that the right way I'm looking at those charts ?

Im afraid so going by todays output but it could be a reload again towards the end of next week.

Kippure

So its the Weather after the 9 pm news tonight where Evelyn will have an up to date forecast on this cold block, interesting.

ninebeanrows

Kippure wrote: »

So its the Weather after the 9 pm news tonight where Evelyn will have an up to date forecast on this cold block, interesting.

Well it won't be good because she will be taking the ECM which is not good!

It flirts with some nice charts at distance to keep winter hope alive.

I just hope the Cold flow can get a bit further east to early on so we can at least have some ice days and a snowy breakdown.

Won't take much to allow some of those -10c 850's hit the east coast but ECM is not nice!

M.T. Cranium

Models are no doubt well into the usual upgrade-downgrade cycle with 06z GFS marking high tide and 12z UKMO low tide. Most likely outcome still somewhere in the middle of the spectrum of all recent output. This still favours a strong thermal gradient across Ireland from east to west, with the most likely western extremity of the arctic front looking to be about midway between Waterford and Cork, north-northwest to around Donegal Bay. That point most likely to be reached Thursday night into Friday mid-day before a retreat east begins. Your local forecast will depend on proximity to this boundary and there will almost definitely be two very different regimes leading to quite a contrast, which of course means forecasting will be difficult.

As to which 12z model is likely closest to the mark, suspect that would be GFS since it seems to be more reliably factoring in feedback from snowfall created during the advance phase of the cold air. This may explain the puzzling aspect of the fast return of the Atlantic on some other models -- don't think that this will play out due to resistance from boundary layer inversion over snow cover. That will have decreasing relevance upstream so if you don't get into the cold air very long, it won't be as delayed getting pushed back. This factor may even apply to eastern Ireland if snow cover gets established.

Harps

Pretty good agreement for the past few days now, the usual small scale upgrades and downgrades but overall easily the coldest week of the winter so far, nothing too exceptional though and all coming to a close by the weekend. Temps close to zero in the inland east during the day and there should be some hard frosts every night. I never expected anything much in Donegal but it'll be nice to see some proper frosts if nothing else

Europe set for brutal cold though, I should be in central Europe this week, would have been flying back from Stuttgart on Friday which is forecast a wind chill of -31C :eek:

200motels

Looking at the 3 different models it's hard to get your head round it, I think the GFS model which has been mostly correct this winter is the one to follow, the ECM has been a disaster this winter, and as for the UKMO it's been in between the two, that's how I think they have performed this winter. I'm open to correction. I think the forecast given after the news is wrong.

Su Campu

Met Eireann don't only use the ECMWF so her forecast will take into account the UKMO, DWD and Hirlam and Harmonie models tool.

I would still go for the breakdown during Saturday and a return to westerlies/southerlies up to around mid month, with the cold staying far to the east.

Sponge Bob

12z ECM shows the peak Cold 850 temps and extent broadly as per the second graphic from Thursday to Saturday and then gradually buggering off back to Germany thereafter.

Someone posted some rather misleading ECM Perturbations above.





I'll watch this again in 24 hours to see whether the serious cold crosses the Pennines/Snowdonia or even whether it digs in over the UK instead of going back to Germany.

snowstreams

Sponge Bob wrote: »

....
I'll watch this again in 24 hours to see whether the serious cold crosses the Pennines/Snowdonia or even whether it digs in over the UK instead of going back to Germany.

Its interesting to see on your second slide spongebob that there is -8c cold off the west coast as well as the east coast! That must be a mistake?

EDIT: Sorry I forgot this was the model thread. I didn't mean to post this message here.

ninebeanrows

The ECM mean Ensembles charts would not lead me to believe the Atlantic is going to forge through easily.

Maybe briefly before the block reasserts itself.

If your a Kent resident, i think you could hang on to the cold for the lot.

Bit to go in this yet i feel.

JanuarySnowstor

Weathercheck wrote: »

The ECM mean Ensembles charts would not lead me to believe the Atlantic is going to forge through easily.

Maybe briefly before the block reasserts itself.

If your a Kent resident, i think you could hang on to the cold for the lot.

Bit to go in this yet i feel.

Not many from Kent on here Matty.
The models have been close to a disgrace of late hopping between different scenario's. The UK MET have yet again come out of the whole thing quite superbly and their longe range forecasts have improved no end.
Don't forget GP eluded to a temporary switch to westerlies before the East takes control again.
I think the 2nd week of Feb will be the week that we finally see proper cold though the extreme uppers will have disappaited and we will be looking at -8's to -10's which of course is ample for snowfall.

Overall though for me it's been a rubbish Winter and I don't really care what Feb throws at us, it'll be too little and far too late

ninebeanrows

I've seen enough from the ECM postage stamps to say that hope remains.

The Atlantic will attempt to make inroads but any outcome past 120hrs is very uncertain.

From a snow breakdown / snowy interlude before easterly pushes back / to mild southweterlies

All this possible at T120

Kippure

Weathercheck wrote: »

The ECM mean Ensembles charts would not lead me to believe the Atlantic is going to forge through easily.

Maybe briefly before the block reasserts itself.

If your a Kent resident, i think you could hang on to the cold for the lot.

Bit to go in this yet i feel.

Gp on NW has the veiw ( and its in his winter forecast ) That if the atlantic push,s in, it will be short lived. As a scandi block is trying to form and link with greenland high. Thats for the second half of the month. Its timed with the NAO going negetive again?

ninebeanrows

Kippure wrote: »

Gp on NW has the veiw ( and its in his winter forecast ) That if the atlantic push,s in, it will be short lived. As a scandi block is trying to form and link with greenland high. Thats for the second half of the month. Its timed with the NAO going negetive again?

Yes it would appear the block make get eroded back from Ireland for a while but remains strong and dominant feature in the output after 120hrs.

A snowy outcome could return in the morning i feel, then again it could be the opposite, but things are very finely balanced and extremely uncertain. Not often a 5 day mode output could be subject to such a change.

Kippure

Weathercheck wrote: »

Yes it would appear the block make get eroded back from Ireland for a while but remains strong and dominant feature in the output after 120hrs.

A snowy outcome could return in the morning i feel, then again it could be the opposite, but things are very finely balanced and extremely uncertain. Not often a 5 day mode output could be subject to such a change.

We could be saying that after 120hrs isnt FI anymore but before it, it is....

Another trend popping up in the models...:)

Musicman2000

The Gfs pub run on the way, Will things push further west? or head back to Europe:) Evelyn was fairly sure about the mild weather for the weekend, but GP over on netweather thinks a reload could be possible from the north or east, Interesting time ahead.

ninebeanrows

GFS 18z

slightly further west compared to the 12z at T72

Musicman2000

Weathercheck wrote: »

GFS 18z

slightly further west compared to the 12z at T72

Yup a slight move further west:)

ninebeanrows

The high develops a centre over Norway, could help keep it up
Smashing run so far!

delw

Weathercheck wrote: »

GFS 18z

slightly further west compared to the 12z at T72

and still further west at T84,better so far

Trotter

Theres a definite stall at T96 compared to the 12z run.

Musicman2000

Trotter wrote: »

Theres a definite stall at T96 compared to the 12z run.

Ill take its as far as t96:)

pistolpetes11

The Cold is further West again !

GFS 18z @ 96 hr



GFS 12z @ 102 hr

ninebeanrows

Musicman2000 wrote: »

Ill take its as far as t96:)

Yea looks very good. This rollercoaster is rough.

Onto the 0z. How uncertain is this? Absolutely crazy, never seen so much discrepancy at T96.

patneve2

GFS 12z everything further west...this has to be one of the longest if not the longest model saga ever...it just keeps going on and on

Musicman2000

Weathercheck wrote: »

Yea looks very good. This rollercoaster is rough.

Onto the 0z. How uncertain is this? Absolutely crazy, never seen so much discrepancy at T96.

Yeah it really is madness dont think the models are getting a grip on how strong the block is, We got till Sunday anyway Lets see can the 00z keep up the trend.

K_1

18Z an upgrade, but being the pub run, and taking DM2's advice from earlier, I'd be inclined to wait for the 00z's before making a call.

In the meantime, I might just leave this FI beauty here: :P



Other than the breakdown though, it looks like largely dry cold.

Harps

The whole of Europe still under extreme cold by next week, whatever about us its definitely going down as a historic event on the continent. Safe to say we don't want things this bad



A nice GFS run for us with the Atlantic kept at bay for the most part, I'd give the 12Z ECMWF a lot more credence but with so much difference on we go just as clueless as before!