Prolonged cold spell on the way

Harps

Theres not been a cloud in the sky all day here, hard to believe theres floods down there!

ninebeanrows

I feel we may be getting to some sort of consesus agreement here.

A disslotion of the ECM shortwave idea.

Has the effect of briefly warming the uppers.

So Tuesday-Thursday actually look very cold with maxima falling very low by Thursday and some reall harsh frosts.

Then Friday sees a brief interruption as a Frontal system pushes south brining in brief warmer uppers.

During Saturday this then drags in deep Sig Cold with uppers down to -10c in the east.

The exact position of the driver Shortwave to the east of England will be crucial in determining areas most prone to precip etc.

We want somewhere like SE England to drive in ENE winds.

So summarising. Tuesday-Thursday, Severe frosts + some wintry showers near coastal fringes of North and East. Maxima falling.

Friday - Divider Day - Briefly less cold maxima upto 4-5c with rain from a front pushing south, Some High ground will see this fall as snow.

Saturday - SIG cold air introduced, wind direction could be N or E, determined by shortwave east of England. Precip as snow to sea-level.

After this seems highly likely to be at least a few days of Easterly feed with SIG cold air.

maquiladora

http://91.121.84.31/modeles/gens/graphe_ens3.php?x=111&ext=1&y=2&run=12&runpara=0

GFS operational run was one of the coldest from the 27th onwards, at times the very coldest.

You can see the uncertainly over the shortwave and then in FI the uncertainty about the breakdown begins around Dec 1st.

JanuarySnowstor

The general trend is looking dryer for Ireland.
We need that Greenland high to intensify in situ not South.
Small nudges in every model can lead to a signiifcany downgrade in 5 days time.
We need the 18z and ECM to start upgrading a bit.

Of course the overall consensus still looks excellent for bitter cold, but i'm getting greedy now in the search for snow!

maquiladora

JanuarySnowstor wrote: »

The general trend is looking dryer for Ireland.
We need that Greenland high to intensify in situ not South.
Small nudges in every model can lead to a signiifcany downgrade in 5 days time.
We need the 18z and ECM to start upgrading a bit.

Of course the overall consensus still looks excellent for bitter cold, but i'm getting greedy now in the search for snow!

FI is about 90-100 hours with this setup I think. I wouldn't get into a sweat over precip or no precip beyond that, I think thats still totally up in the air - again no pun intended.

12Z ECM should be very interesting...

Kippure

I put together a slide show of last winters snow.

Enjoy



http://www.youtube.com/watch?v=O1LdUNi20kA

rilz

I think we all know nearer the time we usually get downgrades on the charts. Happens every year. Maybe we might get upgrades for a change. Lookin forward to the frost n fog anyway.

Birdnuts

I can confirm that snow has fallen and stuck on the higher peaks of the Wicklow Mtns:D

maquiladora

12Z ECM not looking too bad at 96 hours? 120 and 144 will be interesting...

ninebeanrows

maquiladora wrote: »

12Z ECM not looking too bad at 96 hours? 120 and 144 will be interesting...

Yup broadly similar to GFS at 120hrs perhaps better.

Interesting to see where the shortwave ends up what pressure alignment
we get and whether we can look forward to some Lake Effect!

Harps

"Possibly some sleet on hilltops towards the end of the week"

Why are met eireann so conservative when it comes to a mention of snow??

Theres been sleet and snow on hilltops around here for the past two weeks, surely if it gets considerabely colder then its logical to say there'll be snow

Elmo5

oooh an interesting run alright - 12z ECM

ninebeanrows

144hr very cold, almost fantastic synoptic but we arent quite into a Strong Easterly flow, very cyclonic, perhaps slow-moving fronts of snow possible but i want Easterlies over the Irish sea and lake effect!

gally74

folks,

can anyone do a Weather 101 here for some of us, the different models etc.

maquiladora

Out to 168 and we don't get -8 850's over us at all really. -4 and -6 isn't going to be enough for snow at low levels from this setup.

Weathercheck

Weathercheck wrote: »

144hr very cold, almost fantastic synoptic but we arent quite into a Strong Easterly flow, very cyclonic, perhaps slow-moving fronts of snow possible but i want Easterlies over the Irish sea and lake effect!

Yeah it's hard to know what to think because it's 6 days away and subtle changes are big moves in the outcome.
I don't like that low forming in the sw approaches at 168 either as in it comes perhaps before any decent cold has bedded down.
At beyond 96 though it's all academic.

Su Campu

Harps wrote: »

"Possibly some sleet on hilltops towards the end of the week"

Why are met eireann so conservative when it comes to a mention of snow??

Theres been sleet and snow on hilltops around here for the past two weeks, surely if it gets considerabely colder then its logical to say there'll be snow

The past two weeks? Where? I haven't seen any!

maquiladora

maquiladora wrote: »

Out to 168 and we don't get -8 850's over us at all really. -4 and -6 isn't going to be enough for snow at low levels from this setup.

That would be my concern.
This shortwave turns back the Scandi tap and it I feel just would stem the flow of necessary negative dewpoint air leaving us in somewhat of a col.

I wouldn't worry though at this stage.
Much tweaking by this day week

Su Campu

Su Campu wrote: »

The past two weeks? Where? I haven't seen any!

People have posted today that it was snowing today at Sally gap and starting to stick and that kippure is snow capped.
I could see lugnaquilla this afternoon from Arklow and it was plastered in snow from top to bottom.
Artictree has said,Lug has had some snow on the top over a week ago.

ninebeanrows

Reverse Zonality at 168hrs as a low forms over Scotland and heads westwards across the Atlantic!

ninebeanrows

maquiladora wrote: »

Out to 168 and we don't get -8 850's over us at all really. -4 and -6 isn't going to be enough for snow at low levels from this setup.

Reckon you are wrong, ECM is always less excessive with 850hpas and the setup at around 144 onwords is well cold enough, DP's would be very low and 850hpa of -7c is very sufficient in that setup

maquiladora

Story is over at 192 but hey its FI anyway right...

ninebeanrows

ECM not fun at T192hrs :D

Atlantic picking up.

Main problem begins around T120hrs as shortwave over SE England doesn't head fart south enough.

We want the HP to have push further south.

ninebeanrows

maquiladora wrote: »

Story is over at 192 but hey its FI anyway right...

Over!? Very strange set up and very interesting, potentially blizzards moving across Ireland.

Eventually probably milder but look at HP over Scandy.

Harps

Su Campu wrote: »

The past two weeks? Where? I haven't seen any!

Theres been snow in the Derryveagh Mountains, I can see them in the distance and theres been a few days in the past few weeks where theyve been white.

Think pangea mentioned the Bluestacks in the south of the county had snow as well

Pangea

Oh my god someone give gerry murphy a good kick up khyber, "possability of sleet in the mountains towards the weekend", We had sleet here in lower levels here a few days ago never mind the very cold spell approaching!
Bring back the eagle.

Su Campu

Deleted User wrote: »

People have posted today that it was snowing today at Sally gap and starting to stick and that kippure is snow capped.
I could see lugnaquilla this afternoon from Arklow and it was plastered in snow from top to bottom.
Artictree has said,Lug has had some snow on the top over a week ago.

Lugnaquilla fair enough, it's over 900m, but "hilltops for the past two weeks"? :rolleyes:

maquiladora

ECM FI seems kind of weird. Huge question mark for everything from 144 onwards that run for me anyway.

Good agreement between GFS and ECM up to 120 though.

Pangea

Harps just seen your post ,similar post to mine good man yourself.
Su Campu a poster from mayo posted a picture of nephin beag covered in snow.
Also one of the hilltops here in south donegal (not the bluestacks) had snow last week.
Also Ive heard numerous people say the road near teelin had a good bit of snow on it last week, (it was even touching the bottom of the car).

Su Campu

Pangea wrote: »

Harps just seen your post ,similar post to mine good man yourself.
Su Campu a poster from mayo posted a picture of nephin beag covered in snow.
Also one of the hilltops here in south donegal (not the bluestacks) had snow last week.

Fair enough, I remember the Mayo one now.