Prelude to Cold Weather/Snow - Sun 25th Feb (Onwards)

carltonleon

Ah lads , leave it out ... You have me super excited .... the wait arrgghhh the wait !!!

M.T. Cranium

Point taken about the level two idea, but I do think our thread title needs to be edited to say something about heavy snowfall potential now, and from Mon 26th Feb would be a good change as no model now has the cold air arriving before then.

lawred2

So have we passed from the fantasy to the reality then?

esposito

lawred2 wrote: »

So have we passed from the fantasy to the reality then?

Nope. Still a bit far out imo although it’s looking promising.

Liffey4A

We could have a thread titled "Will it snow in?" and all those questions could be asked in there or perhaps point people towards the Netweather.tv snow radar app. 😉

Gaoth Laidir

Overnight ECM doing what we want and shifting that high and its inversion away from us, allowing in a deep cold pool from the east. No problem with 700 and 500 hPa temperatures according to this run. Tuesday night into Wednesday delivering good precip totals for the east and now other areas too.

Note: the ECM has a slight low bias when it comes to cold land convection (it kills off showers over cold land too quickly) so the chart below could be adjusted to show precip making it farther west inland from the east.

Of course it's all just a model run but it shows the trend of the ducks getting lined up nearer to the event. I noted last night that the forecast surface dewpoints for northern Scandinavia* were a few degrees too high compared to what they were actually getting, even at T+6 hrs, so the model trumpeters are still just wetting their lips in preparation for the start of the piece. (*Dewpoints as low as -36°C in northern Sweden compared to a forecast of about -33)

24-hr total precipitation by Wednesday afternoon
https://weather.us/model-charts/euro/great-britain/precipitation-total/20180228-1200z.html

500 hPa cold pool
https://weather.us/model-charts/euro/great-britain/tempature-500mb/20180228-1200z.html

700 hPa
https://weather.us/model-charts/euro/great-britain/temperature-700mb/20180228-1200z.html

DOCARCH

M.T. Cranium wrote: »

Point taken about the level two idea, but I do think our thread title needs to be edited to say something about heavy snowfall potential now, and from Mon 26th Feb would be a good change as no model now has the cold air arriving before then.

Did a minor thread title edit.

I'd be inclined to wait until (at least) tomorrow before adding warnings.

Reckless Abandonment

From a Dublin point of view I'm not mad on the GFS it keeps the flow South of east most of the time. Wicklow mountains could soak up all the good stuff. ECM is epic east or north easy winds all the way. This is the best model watching in years.

ninebeanrows

Very nice ensembles mean @ 144hr....lessening yesterday's concern of a southerly shift....







My oh my....the 168hr MEAN chart has the -12 850hPa isotherm into Ireland

Unprecedented in recent times

pjohnson

How do you stop pipes from freezing? Had trouble 2 weeks ago with them before this shítshow makes things worse.

tiegan

Is this the real life? Is this just fantasy?
Caught in a landslide, no escape from reality
Open your eyes, look up to the skies and see


New charts are sending shivers down my spine and putting the hackles up on my neck. Think its going to be epic, one way or another!! This thread creates such anticipation!! Cheers Kermit

Lucreto

I was standing at the train platform and I overheard a conversation.

It's meant to get cold again next week?

Me: pokerface

now online

My Google home says snow is expected in cork on Tuesday!
Loving the updates here, thanks everyone!

Calibos

Oh, I'm liking the look of this from Gaoth Laidirs Precipitation link for Wedneday! Bray under the highest intensity!



Am I reading that right 20mm precipitation over 24 hours. Dry snow is a factor of 10 isn't it. So that would mean 20cm of snow!!??

Needless to say I'm not building my hopes up for that amount but its great to see on the charts all the same.

George Sunsnow

pjohnson wrote: »

How do you stop pipes from freezing? Had trouble 2 weeks ago with them before this shítshow makes things worse.

Lag them
Hardware store

I’m expecting these charts to continue showing what we see this morning and to verify

Calibos

George Sunsnow wrote: »

Lag them
Hardware store

I’m expecting these charts to continue showing what we see this morning and to verify

Have a bathroom sink in one of our rental properties that has an outside drain pipe with a mediocre 'fall' that froze and blocked up with ice in 2010. What would you suggest I wrap that with my Arklow friend?

pjohnson

George Sunsnow wrote: »

Lag them
Hardware store

I’m expecting these charts to continue showing what we see this morning and to verify

Thanks. Will try

Gaoth Laidir

Calibos wrote: »

Oh, I'm liking the look of this from Gaoth Laidirs Precipitation link for Wedneday! Bray under the highest intensity!



Am I reading that right 20mm precipitation over 24 hours. Dry snow is a factor of 10 isn't it. So that would mean 20cm of snow!!??

Needless to say I'm not building my hopes up for that amount but its great to see on the charts all the same.

Dry snow would be more like 30-40, so you do the maths on that!

red_bairn

Calibos wrote:

Oh, I'm liking the look of this from Gaoth Laidirs Precipitation link for Wedneday! Bray under the highest intensity!

What the feck is "Dunleary"! xD

M.T. Cranium

If the ECM scenario verified, I think we would be looking at 20 to 40 cm snowfalls over large parts of central and southern counties, 10 to 20 in parts of Ulster, and some much lower amounts in parts of Connacht, perhaps into north Clare. This looks very similar to the maps for 3-4 Feb 1947, and there are few if any other examples, perhaps 31 Dec to 1 Jan 78-79.

So once again, I am commenting on what maps indicate, not what I am forecasting, this only has a slight chance of verifying verbatim, details may change considerably. You feel with all these varying snow scenarios, somebody's going to have a heavy snowfall in the reality phase of this campaign.

Calibos

Gaoth Laidir wrote: »

Dry snow would be more like 30-40, so you do the maths on that!

Jesus!! 2 and a half feet!! :eek:

I was going to say that we 'only' got about 12cm that first night of November 2010 and I don't expect anymore than that. Then I remembered that we got that 12cm in the space of only 2 hours. I guess it depends how long the wind direction is maintained and if we stay under the streamers.

pad199207

Gaoth Laidir wrote: »

Dry snow would be more like 30-40, so you do the maths on that!

Say that again?????

lawred2

Calibos wrote: »

Oh, I'm liking the look of this from Gaoth Laidirs Precipitation link for Wedneday! Bray under the highest intensity!



Am I reading that right 20mm precipitation over 24 hours. Dry snow is a factor of 10 isn't it. So that would mean 20cm of snow!!??

Needless to say I'm not building my hopes up for that amount but its great to see on the charts all the same.

Would love to see that for Portmarnock/Malahide

SEPT 23 1989

400mm of snow would close the city

Calibos

red_bairn wrote: »

What the feck is "Dunleary"! xD

I was once asked by a yank how to get to Dun...log...hairy (Dun Laoghaire)

channaigh

So excited have the kids wound up off to buy snow gear now

red_bairn

M.T. Cranium wrote:

So once again, I am commenting on what maps indicate, not what I am forecasting, this only has a slight chance of verifying verbatim, details may change considerably. You feel with all these varying snow scenarios, somebody's going to have a heavy snowfall in the reality phase of this campaign.

MT, when is everything locked in place? Are we talking about this event starting from Monday onwards?

Snow angel

What time does the 6z start rolling out?

Gaoth Laidir

Calibos wrote: »

Jesus!! 2 and a half feet!! :eek:

I was going to say that we 'only' got about 12cm that first night of November 2010 and I don't expect anymore than that. Then I remembered that we got that 12cm in the space of only 2 hours. I guess it depends how long the wind direction is maintained and if we stay under the streamers.

While coastal convergence from land friction does enhance sea-effect convection in coastal areas, I can't see anywhere getting 60-80 cm of snowfall from this, except maybe some northeast-facing upslopes under 24 hours of streamers.

JCX BXC

Snow angel wrote: »

What time does the 6z start rolling out?

Begins at 9:30 and finishes just before 11. For the GFS