Turning Colder Thursday - Wintry Showers/Snow to High Ground

Kermit.de.frog

Thursday 3rd --> Sunday 6th

Turning colder from the northwest. Source of the cold air is the east coast of Greenland so it will be carrying a bite. As well the weather becoming ever more anti cyclonic from Thursday morning.

Increasingly unsettled with snow on high ground but to lower levels at times as well. Night time frosts and icy patches.

Wintry showers heaviest and most persistent in the north and west but there will be several frontal troughs around effecting other parts as well.

Remaining cold in to the early days of next week as well.

Daytime temperatures between 2 and 9c - coldest in the east and midlands.

Night time temperatures 0 - -3c, coldest again in the east and midlands.

There is a risk of significant snowfall for the end of the week and weekend on high ground above circa 350 metres particularly further east. Minor desposits at lower levels occasionally (1 - 2 cm) particularly through early Friday.








There is also a risk of local flooding through the weekend with persistent heavy showers/rain.

On the up side it won't be particularly windy at any stage.

Mars Bar

I've been stranded in the middle East due to the virus and made attempts to get home twice, unsuccessfully. I'm due to land in Dublin at about 10.30pm on Thursday night. If it could just pace itself until I land and then it can bucket it down all it likes!

I'm going to die a death in those temps though. I put on a jacket at 20 degrees

Graces7

Hastily mentally checking to see if there is anything I absolutely need this week from over the water.... the ferry will be fine but the roads may not be...

Already stocked, and everything by the dwelling.... Let it rip! Maybe that last snowman I have been hankering for for years will get built..

I took this either last year or the one before... Hoping we do better than this

And there will be great delight here....

pauldry

December has gotta bring a blizzard. After all its 2020.

All Ireland Semis might be in snow this year.

lawred2

This sounds like a forecast for some bitterly cold muck

pauldry

Yes inland will prob do best.

Coastal locations will be 7c by day and prob 3 or 4c by night due to wind

Graces7

pauldry wrote: »

Yes inland will prob do best.

Coastal locations will be 7c by day and prob 3 or 4c by night due to wind

Yes we tend to lose out. Although not in Orkney! Further north of course. And it was windier there than here by far.

YanSno

Dew point and temp profiles are too marginal, sleet and wet snow at best on high grounds above 300m

Supercell

lawred2 wrote: »

This sounds like a forecast for some bitterly cold muck

That's all I'm expecting here to be honest, not looking forward to it.

Nqp15hhu

YanSno wrote: »

Dew point and temp profiles are too marginal, sleet and wet snow at best on high grounds above 300m

With freezing levels of under 500 metres it should surely snow below 300 metres, especially at night.

The forecasts actually predict subzero mins on Thursday night anyway, so that shouldn’t be a factor.

Danno

Supercell wrote: »

That's all I'm expecting here to be honest, not looking forward to it.

https://www.boards.ie/vbulletin/showthread.php?p=105514334

The December 10th 2017 is an interesting comparison/benchmark for this event.

Nqp15hhu

Soundings from tropical tidbits. The wet bulb zero level is at sea level in the NW of the island by 6am. With it being around 400m at midnight.

Thursday evening is subzero across the island.

Nqp15hhu

Soundings from south to north on Thursday. So not productive for snow during the day on Thursday. But yes by afternoon (except south).

Cluedo Monopoly

High ground?? Excellent!

Gonzo

Cluedo Monopoly wrote: »

High ground?? Excellent!

yep high ground only, Thursday will be a wet and cold day for most us, temperatures 2 to 5C and cold rain.





Mostly dry after Thursday and some wintry showers near western and northern coasts over the weekend, maybe a few flirting with eastern coastal areas.

Nqp15hhu

Cluedo Monopoly wrote: »

High ground?? Excellent!

There may be some snow in the evening showers as temperatures drop.

But you can always drive to higher elevations to get your snow fix!

Hooter23

Just cold enough for the rain to feel like ice but not cold enough to turn it to snow...Great

White Clover

Is this event moreso for the Northern part of the Country?

Nqp15hhu

The lying snow line will be around 400m, not 750.

Cluedo Monopoly

Nqp15hhu wrote: »

There may be some snow in the evening showers as temperatures drop.

But you can always drive to higher elevations to get your snow fix!

I love winter hill walking so I will head up as soon as I see white peaks.

Danno

The timing for the bands of precipitation will play a part. Nocturnal cooling can be a factor. It is a marginal event looking at the model outputs, but still time for this to upgrade/downgrade.

Graces7

OK; anyone want to join in a Snow Dance?

KingJeremy

Graces7 wrote: »

OK; anyone want to join in a Snow Dance?

I will!!!

Nqp15hhu

ECMWF has similar 850hPa’s as the ICON on Thursday. So unless a milder low pops up this is the synoptic situation for Thursday.

JanuarySnowstor

Thursday has upgraded all the way through today and now looks like we could see disruptive snowfall for higher ground in the West and South.
All the parameters are met and considering its quite early in the season is indeed remarkable.
Leaving 2010 aside seeing snow falling before Christmas is as rare as hens teeth!!

Water John

Just saw Joanne Donnelly mention the 528 Line today. Can any of the experts explain what that is? I know it's the demarcation of the possibility of snow, but what does the number stand for?

JanuarySnowstor

18z is a cracker with the cold spell going on and on
Daytime maxes around 4 or 5 with very frosty nights early next week
Best start to Winter since 2010!!

Nqp15hhu

On the ICON 18z Thursday has been upgraded. The warmish uppers for Thursday have been replaced by -6c 850pHa. Dew points are now subzero during the day and Ulster appears to be productive for snow throughout the day.

“Limite Pluie Neige” refers to the snow line for precipitation type by elevation.

Nqp15hhu

Thursday is a cold day.

Nqp15hhu

Water John wrote: »

Just saw Joanne Donnelly mention the 528 Line today. Can any of the experts explain what that is? I know it's the demarcation of the possibility of snow, but what does the number stand for?

It refers to the depth of the air column between 500mb and 1000mb.

At 528dcm this refers to a “thinner” air column meaning that the colder air is closer to the surface.

Slashermcguirk

I always had a feeling about this December that something might materialise with snow. It’s been such a strange year including the weather being so up and down. I wouldn’t be at all shocked to see a decent bit of snow this winter

pauldry

I thought it would be mild and mucky but now it looks cold and mucky.

mcburns07

pauldry wrote: »

I thought it would be mild and mucky but now it looks cold and mucky.

Looks quite pleasant for Cork

Cold and mostly sunny.

Reckless Abandonment

I love this time of year. Im back watching the gfs roll out on meteociel frame by frame. Such a warm fuzzy feeling. hope everyone has their tickets for this year roller coster.

sryanbruen

Standard damp cold muck. Any interesting synoptics in FI on model runs also being blasted away by the lack of cold air on the continent courtesy of that Russian high.

Seriously not getting any excitement out of any of this.

Nqp15hhu

Unfortunately the coldest weather now looks to be restricted to the northern third. With snow only likely there.

lostweekend3

sryanbruen wrote: »

Standard damp cold muck. Any interesting synoptics in FI on model runs also being blasted away by the lack of cold air on the continent courtesy of that Russian high.

Seriously not getting any excitement out of any of this.

Jeez, you are very pessimistic lately. Cheer up. It’s December 1st.

Nqp15hhu

Atmospheric soundings for Thursday. South to north.

You need the blue line to be zero almost to the surface for surface snow.

Snow is not happening in the south but with altitude (200-300m) you could get some in the middle third.

Graces7

met ie advisory for "wintry showers"....

pauldry

At least some weather is happening as opposed to many years cloudy misty murky nothingness.

Cluedo Monopoly

I actually love cold foggy/misty days in December. There is something mystical about them.

Nqp15hhu

Graces7 wrote: »

met ie advisory for "wintry showers"....

Their forecast is very low risk. “May turn wintry on high ground”.

Yeah I think that’s guaranteed at this point.

Nqp15hhu

Met Office for Mourne Mountains

Wednesday:

“ A frontal band of rain will push east across the Mournes during the early hours of Wednesday, it will be quite weak and should have cleared east by sunrise. Then it will be a bright start with some early sunshine. Showers will develop and these will be wintery above 500m with slight accumulations on the tops likely.”

Slight accumulations LIKELY

Thursday

“ Sunny intervals and some wintry showers, freezing level around 400m. Moderate Southwesterly winds will veer Northwesterly and it will feel very cold on the hills with a severe wind chill.”

I think that’s more realistic than a possibility of wintry showers at elevation.

Cluedo Monopoly

Not sure how accurate but Croagh Patrick showing light snow on Wednesday night and Thursday.

https://www.mountain-forecast.com/peaks/Croagh-Patrick/forecasts/764

John O.Groats

JanuarySnowstor wrote: »

Thursday has upgraded all the way through today and now looks like we could see disruptive snowfall for higher ground in the West and South.
All the parameters are met and considering its quite early in the season is indeed remarkable.
Leaving 2010 aside seeing snow falling before Christmas is as rare as hens teeth!!

I remember lying snow at low levels before Christmas in 2009 also.

Graces7

Nqp15hhu wrote: »

Their forecast is very low risk. “May turn wintry on high ground”.

Yeah I think that’s guaranteed at this point.

Pessimism is not allowed.

igCorcaigh

John O.Groats wrote: »

I remember lying snow at low levels before Christmas in 2009 also.

I have more memories of the freezing 2009 winter than 2010. Coldest I have ever experienced in Ireland. Everything was covered in ice.

JCX BXC

Looks borderline, but sadly borderline never delivers here. Still fun to watch the charts, the joys of Irish winter.

John O.Groats

igCorcaigh wrote: »

I have more memories of the freezing 2009 winter than 2010. Coldest I have ever experienced in Ireland. Everything was covered in ice.

Indeed. I have a vivid memory of slipping and falling on icy ground on Christmas Eve 2009 and spending Christmas that year with bad bruises on my arse. :(

circadian

igCorcaigh wrote: »

I have more memories of the freezing 2009 winter than 2010. Coldest I have ever experienced in Ireland. Everything was covered in ice.

There was a massive freeze and snow dump in 2009 up north, 2010 eclipsed it but both years were much colder than normal.

snowstorm445

I was in Killarney that Christmas with my family and it was pristine, snow on the mountains, clear skies every day, great weather to go out and head around the National Park. We went there the year before and it was the complete opposite, murky and damp the whole way through. Although the latter would be much more typical of winter in Ireland.

And then on New Year's Eve around midnight, when we were back up in Drogheda, the first snow of the year fell overnight. Honestly perfect weather for the Christmas period, which makes the awful mild washouts we've had since then all the more sad tbh.