FI Charts (T120+ onwards) Winter 2018 **READ MOD NOTE IN FIRST POST**

snowstorm445

squarecircles wrote: »

No mention of the potential cold next week after the 6.1 news.

Seem to deliberately stop with detail after Monday.

Only natural given that this spell of weather isn’t completely guaranteed. There are still many factors that could spoil the party. If it’s still there by Sunday then its probably game on.

Donegal Storm

GFS is showing rain for Monday night with light back edge snow giving a patchy dusting, followed by light north westerlies with wintry showers in the north and west on Tuesday and Wednesday, dry elsewhere with daytime temps of 2-4C.

People going a bit over the top here

Rebelbrowser

Donegal Storm wrote: »

GFS is showing rain for Monday night with light back edge snow giving a patchy dusting, followed by light north westerlies with wintry showers in the north and west on Tuesday and Wednesday, dry elsewhere with daytime temps of 2-4C.

People going a bit over the top here

but ECM a lot colder and you'd always prefer the ECM on your side. Still no guarantees obviously

Donegal Storm

Rebelbrowser wrote: »

but ECM a lot colder and you'd always prefer the ECM on your side. Still no guarantees obviously

I tend to trust the model showing the most boring solution, far more often than not it'll be right. Naturally I hope it's wrong but no point getting excited yet for what might be just a few hours of slush

BLIZZARD7

Donegal Storm wrote: »

GFS is showing rain for Monday night with light back edge snow giving a patchy dusting, followed by light north westerlies with wintry showers in the north and west on Tuesday and Wednesday, dry elsewhere with daytime temps of 2-4C.

People going a bit over the top here

One GFS run, lots of runs showing -7c to -11c 850 temps with slack winds, temperatures would struggle to get much above 0c, during the day, especially with any snow cover, with very severe frosts at night. Also pressure looks low enough during the week for features to pop up at short notice. - No point in trying to forecast where gets snow with any real accuracy beyond 24 hours max in this setup.

Of course this could all go pear shaped still but we're looking good so far.

BLIZZARD7

12z GFS ensembles for roughly Dublin - Mean 850 temps barely get above -5c. Towards the end of the run there are even a few rogue runs that push towards the -15c mark...

typhoony

it's a hair breath away from being a classic setup on the 18z, we've almost got perfect warm air advection up the west side of Greenland and a fledgling scandi high. the difference between cold and very cold is just a tweak away on the GFS.

MJohnston

Couple of other models that are now in range of the 6th too:

WRM's lower resolution 12Z:



ICON-EU 18Z:

pauldry

I wont be at all surprised to see snow next Tuesday for Sligo

1/ Tuesday morning is the most often day Ive seen snow in my life
2/ Early February snowfall has occurred quite a few times since I moved to this house 13 years ago
3/All this Winter has been relatively cool so the peak time for coldness is usually the last week of January and first week February
4/ Sea Temps are now near the lowest they will be so less moderation likely
5/ The most predictable thing to happen would for it not to snow and someday it has to be unpredictable
6/ itl prob only last until everyone gets really excited by it n then melt

gabeeg

Well that's pretty emphatic

Larbre34

Kermit.de.frog wrote: »

lol - oh how wrong...:D

I'll just leave this here.

Kermit.de.frog

EDIT: wrong thread!:pac:

sryanbruen

Watch for charts like this becoming increasingly evident on GFS runs now from beyond mid-month as the model responds to the major SSW.

Donegal Storm

Interesting GFS ensembles, a very clear signal towards well below average temperatures. Of course being the GFS it could be showing a heatwave tomorrow but I've rarely seen almost every run below 0C throughout

nacho libre

Oh look where is the Azore High going?L:) If we could only bank this depiction.

Neddyusa

nacho libre wrote: »

Oh look where is the Azore High going?L:) If we could only bank this depiction.

Not sure it's going anywhere based on that Nacho.
Its quite close to its home; and is it not just getting reenforced by the LPs off Newfoundland and S Greenland?

Not that a 2 weeks + chart matters a jot anyway :pac:;)

nacho libre

Neddyusa wrote: »

Not sure it's going anywhere based on that Nacho.
Its quite close to its home; and is it not just getting reenforced by the LPs off Newfoundland and S Greenland?

Not that a 2 weeks + chart matters a jot anyway :pac:;)

Well it's gone far enough a way to introduce colder air. Also if the Canadian part of the vortex is obliterated , would it not then likely start moving north to link up with the surface high over Iceland? It's all open to change as you say, but the GFS is showing these kind of charts because of the proposed stratospheric warming.

sryanbruen

I'm liking the looks of weeks 3 and 4 on the ECM.

Donegal Storm

Donegal Storm wrote: »

GFS is showing rain for Monday night with light back edge snow giving a patchy dusting, followed by light north westerlies with wintry showers in the north and west on Tuesday and Wednesday, dry elsewhere with daytime temps of 2-4C.

GFS was largely right then a full 5 days out, even some of the hi-res models on the day were less accurate. It slightly underplayed snow potential but an impressive performance overall considering other models were showing almost nationwide snow and ice days. As I said at the time, always trust the most boring solution!

Kermit.de.frog

Donegal Storm wrote: »

GFS was largely right then a full 5 days out,

No, it was not.

pistolpetes11

I had 5hours + frontal snow and backedge was rain drizzle so it got it completely wrong way around for my area.

Donegal Storm wrote: »

GFS was largely right then a full 5 days out, even some of the hi-res models on the day were less accurate. It slightly underplayed snow potential but an impressive performance overall considering other models were showing almost nationwide snow and ice days. As I said at the time, always trust the most boring solution!

Donegal Storm

Kermit.de.frog wrote: »

No, it was not.

In what way? As I said it slightly underplayed snowfall but overall it was a pretty good effort. This was the GFS snow forecast for this morning at the time I posted that, it largely stacks up with reports on here. ECMWF had 6cm+ across large swathes of the country at the same time.

It also got temperatures and shower activity today fairly bang on.

MJohnston

Donegal Storm wrote: »

In what way? As I said it slightly underplayed snowfall but overall it was a pretty good effort. This was the GFS snow forecast for this morning at the time I posted that, it largely stacks up with reports on here. ECMWF had 6cm+ across large swathes of the country at the same time.

It also got temperatures and shower activity today fairly bang on.

Not quite:

Donegal Storm

That's from the 2nd of Feb(American format), this is the chart for the 1st showing 6cm+ in most of Leinster and Ulster

MJohnston

Donegal Storm wrote: »

That's from the 2nd of Feb(American format), this is the chart for the 1st showing 6cm+ in most of Leinster and Ulster

No, it isn't, I have weather.us set to use my Dublin timezone and units, so it's from the 1st of February. The 12z is the hint there, you posted the 00z, and Zulu time is tied to GMT, so there's no way the GFS 12Z and an ECM 00Z can be from the same time.

Oneiric 3

Donegal Storm wrote: »

In what way? As I said it slightly underplayed snowfall but overall it was a pretty good effort. This was the GFS snow forecast for this morning at the time I posted that, it largely stacks up with reports on here. ECMWF had 6cm+ across large swathes of the country at the same time.

It also got temperatures and shower activity today fairly bang on.

The snow that fell here yesterday evening came on the back of the front, which, the GFS, above any other main model, got spot on.

Oneiric 3

Anyway, arguing about which model forecast the pitiful amounts we actually saw more correctly is pointless.

patneve2

The far reaches of FI are starting to look interesting. Possibly another 10-12 days of cold westerlies followed by a PV split and a North Easterly/Easterly? AO index projections look very good today. We'll see. In any case, a lot of people on different weather forums are seriously starting to ramp up this SSW.

nacho libre

""This would *not* fit the criteria of a mid-winter SSW defined in Charlton and Polvani (2007). They specify events in which the zonal winds stays easterly for more than 10 consecutive days as final warmings.""

nacho libre

Oneiric 3 wrote: »

Anyway, arguing about which model forecast the pitiful amounts we actually saw more correctly is pointless.

Well the GFS is usually the one to ramp up the potential, so it's interesting in that respect to compare them. By the way what was your wet bulb temperature last night during the snow?:D
I just hope we all get one snow fall to crow about before winter ends. I long to see M.T. saying the following in his forecast: There is a strong possibility of significant snow fall to lower levels... courtesy of a siberian beasterly!