Cold Spell Late Feb/ Early March Technical Discussion only MOD NOTE POST #1

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JanuarySnowstor wrote: »

@ Cork fans

I made a comment earlier today that it might be bordeline for the South coast on Thurs night...I no longer think this after upgrades today.
Looks serious and epic!!
If I had to pick a sweet spot would go with Carlow

Also, and a big also, are we forgetting the wind issue?
Looks storm force to me coinciding with high tides

✓b]Red warning a certainty[/b]

I was starting to get worried reading the previous few posts !
I'm glad that's sorted

Elmer Blooker

Excellent 18z. Out to +144 and cold sinking south.

SleetAndSnow

SleetAndSnow wrote: »

This GFS has taken a very weird turn of events. Last run it was basically saying all cold gone by friday evening. Now its showing snow well off the cork coast still on Monday evening. Its either an outlier or else it has copped onto something.

Yep, I'd tend to agree. It doesn't want to give much snowfall over the country at all Thursday night into Friday. I hope the next ECM run doesn't copy it.

SleetAndSnow

If I read this correctly 18Z basically has snowmageddon out of the picture, while the other 18z's rolling out (HIRLAM etc) are still showing the low moving NW words. I guess it all depends on UKMO and ECM 0z now, but they have been fairly sure its going to keep going with a snowmageddon and a warm up. GFS 18z would show the real strength of this cold high pressure which is what we expected, but its just crazy how uncertain we are when this is basically a day away at this stage. If the GFS is correct I would remove the chance for a red alert this week really (most likely)

hatrickpatrick

Any realistic chance of the forecasted rain / sleet on Friday evening for Dublin changing - either to dry or snow - between now and then? My own knowledge of forecasting is in uncharted waters with this combination of the rain storm approaching from the South and the cold spell. How sure are we that it'll be wet n Friday evening for Dublin?

George Sunsnow

Bbc 10 pm news forecast as attached has the snow all the way up to Sligo still and rain into cork as it clears

JCX BXC

Love the GFS 18z, continues the cold snap for a few days

SleetAndSnow

George Sunsnow wrote: »

Bbc 10 pm news forecast as attached has the snow all the way up to Sligo still and rain into cork as it clears

also something we would rather not see down here. If one of the models predicted the blizzard + the cold staying now that would be ideal! I'd prefer the blizzard over prolonged cold though personally

Gremlin

But the one thing about the 18Z GFS is it keeps us in a bitterly cold ENE flow right throughout the weekend and into next week?

Musicman2000

SleetAndSnow wrote: »

also something we would rather not see down here. If one of the models predicted the blizzard + the cold staying now that would be ideal! I'd prefer the blizzard over prolonged cold though personally

Still looks good for the east and south east , not the very far south west of Ireland.

TheMilkyPirate

JCX BXC wrote: »

Love the GFS 18z, continues the cold snap for a few days

But completely nullifies possibly the biggest snow event this country has seen in the last 40 years?? No thanks

George Sunsnow

JCX BXC wrote: »

Love the GFS 18z, continues the cold snap for a few days

Remember Siobháns radio forecast this morning at 755 am
She said then “and I hate to say it into the early days of next week”

And that was said this morning

Any 80’s spell I experienced always always had forecasters delaying an end compared to the last time they said it would end

Same was going on Xmas week dec 2010

Musicman2000

I think some of you need to watch the BBC forecast that was just on . And take that GFS run with a large pinch of salt

glightning

A more accurate description would be “biggest snow event for the south in 40 years”. Not the case for the north! As I currently see it, this event will not deliver enough snow to the north to challenge any of our biggest falls in the last 10 years.

SleetAndSnow

Musicman2000 wrote: »

I think some of you need to watch the BBC forecast that was just on . And take that GFS run with a large pinch of salt

indeed, considering GFS 18z runs of the past (yes some have been reliable but majority usually change iirc) I am awaiting UKMO and ECM 0z, along with GFZ 6/12z mainly then we should have a pretty accurate picture of the way things are planning out. If the models aren't aligned tomorrow then something is up

munsterlegend

Musicman2000 wrote: »

I think some of you need to watch the BBC forecast that was just on . And take that GFS run with a large pinch of salt

the morning models will be interesting as ever. MT very optimistic of no great thaw on Friday.

George Sunsnow

TheMilkyPirate wrote: »

But completely nullifies possibly the biggest snow event this country has seen in the last 40 years?? No thanks

Don’t worry,there’s what 2 more low pressures lining up for a go
I do think there’s at least going to be stab at the southeastern quadrant which is a line from cork city to Dublin up through mid Leinster before moving back southwestwards perhaps
The solution I expect will be a compromise that see’s the cold hanging on in some fashion or other like that,I can smell it
All win win really I expect

sdanseo

Deleted User wrote: »

Yep, I'd tend to agree. It doesn't want to give much snowfall over the country at all Thursday night into Friday. I hope the next ECM run doesn't copy it.

Agreed. ECM resolution of Thursday is absolutely perfect and if it didn't change at all there'd be a lot of happy snow bunnies.

If the GFS verifies though, skip forward a few frames as it shows a decent snow reload for the east into Saturday.

Both options hammer the south coast hard. Hope you got your bread and milk.

lucernarian

Gaoth Laidir wrote: »

On my screen the image seems normal width

Yes, but what we get after midnight, the UK or at least the North Sea should be getting now. It's not happening, and snow depths in the UK are sporadic and struggling to reach more than 1 cm. We should be seeing 8 or 9 there already, according to models. They were higher earlier but has been a lot of melt there this evening, despite wbt a few degrees below zero. Ground temperature is still a problem, and here too. We need some continuous heavy showers to lay a base for further accumulations, but right now it's not happening.

Anyway, I hope I did give things a kick up the arse a bit but there's still an awful way to go to reach some of the depths forecasted (up 15 cm by me in Dublin by Thursday).

Good and honest post there. I'm a bit surprised by the amount of snowfall so far but we both know what's in store tomorrow. The 850 hPa temperature is still to drop another 2 or 3 degrees and over a long sea fetch.

Gremlin

Meanwhile the Irish Sea is really starting to liven up.

NAGDEFI

JCX BXC wrote: »

Love the GFS 18z, continues the cold snap for a few days

I do too. And there's still tonnes of snow. Not 1982 but plenty!!

pistolpetes11

Rite it appears boards is back to normal now , so Model / Technical Discussion only in here please

Donegal Storm

The front seems to break up on the south coast on the GFS, giving just patchy light snow for most and only a few cm at best. Still no consensus this evening it seems though so no point looking at any one run in too much detail. Tomorrow evening hopefully it'll be fairly nailed on


As for tonight, I'd echo others disappointment. Still not much going on in the Irish Sea at all, some heavier showers popping up but no organisation so they're just blowing over in 10 minutes. Only had one brief shower here since 6pm which topped up the earlier dusting, if things don't pick up dramatically then I'm not seeing any major accumulations at all by morning. Seems to be a bit more happening now but its painfully slow in kicking off

lucernarian

Khalid Millions Grouch wrote: »

I was starting to get worried reading the previous few posts !
I'm glad that's sorted

Very good point, GFS and ICON were quite indifferent about the cold air at times. That analogy about cold syrup being hard to shift with warmer water seems appropriate here

SeaBreezes

Recent lightening strikes in Dublin area:
http://en.blitzortung.org/live_lightning_maps.php?map=10

Gaoth Laidir

lucernarian wrote: »

Good and honest post there. I'm a bit surprised by the amount of snowfall so far but we both know what's in store tomorrow. The 850 hPa temperature is still to drop another 2 or 3 degrees and over a long sea fetch.

For heavy showers it's important to look at 700 and 500 hPa temperatures, which will be much lower tomorrow, allowing deeper convection and heavy showers.

In the satellite animation of the last 3 hours below the coldest upper pool (500 hPa) is that area of blue cloud tops moving westwards over the North Sea. Tops are now down to around -40 °C, and 500 hPa temperature is similar. That cold pool will be over northern England tomorrow midday, with around -42 °C over the east of Ireland. Should be seeing some snowage by then.

https://weather.us/satellite/england/top-alert-15min.html#play

mickmackey1

Well this one leaves no room for doubt, the snowiest forecast I ever remember -

Meteorite58

For me the ECM and the ICON have been probably the most consistent with the last few runs. If anything Icon showing more snow in this run in the southern half of the country. It still tops the poll as regards wind speed with the ECM a close second I think although the GFS looks a lot windier in the 18Z.

This run sees the storm slow/ stall more under lands End just in the right position to turn into a snow making machine.

That would be one hell of a blizzard.

sdanseo

Meteorite58 wrote: »

For me the ECM and the ICON have been probably the most consistent with the last few runs. If anything Icon showing more snow in this run in the southern half of the country. It still tops the poll as regards wind speed with the ECM a close second I think although the GFS looks a lot windier in the 18Z.

Quoting myself again. Must be a megalomaniac.

sdanseo wrote: »

Depends which model you pick out of the bingo drum at this stage

GFS for example showing nothing but snow

ECM would give rain for south of Dublin/Galway from Friday afternoon but by the time that happens there's not too much precipitation left.

ICON has us all building igloos.

If it's any sign of consistency - or maybe a sign of how difficult the scenario is the model - of the three eventualities above only one is still the same, the ECM. The other two have changed entirely. ICON now much further south, still valid for the south coast only (edit: and Wicklow/Kilkenny). GFS doing much the same.

Villain

Harmonie has snow as far north as Newry over the Border by midnight Thursday night.