Cold Spell - Snow & Ice Possible Thursday 8th / Friday 9th

Iancar29

Heres my 2 cents on tomorrows front.

Looks like a good portion of the country will see some settling snow but as its a weak front it won't cause too much disruption, certainly has been heavier more localised falls in recent weeks.


Theta-E values look good currently for full snow down to low levels however 1c up and it'll be wet snow/mess for many.


So why are we looking at a fairly weak amount? Well If we look at the wider picture we can see that the pressure gradient is fairly weak which leads to less forcing.


Associated lapse rates then due to the small temperature gradient at t500 are also quite low.



So overall, alot will see some snow tomorrow night with a nice dusting for many. Nothing to cause alarm IMO. Best for both snow bunnies and people who are worrying about work issues.

Larbre34

PukkaStukka wrote: »

Might be because that forecast is prerecorded earlier?

Fine, pre-record if they must but not so far ahead of time that they are contradicting their own information. Daft.

highdef

grenouille1966 wrote: »

I don't expect much anywhere on Monday night...3cm is nothing...a dusting at best...we had that in Dublin 15 a couple of weeks ago.

I don't think anywhere in Dublin got 3cm. Was that measured on hard level ground (concrete, tarmac, that kind of thing), not grass?

A dusting is when surfaces are just about covered. Think of the dusting of icing sugar on a Victoria sponge cake.... There's no depth to it, it's just a bare covering. 3cm is a decent of snow on solid ground, over an inch in old money. This would be easily enough to cause significant travel disruption. Was this the case?

gozunda

Iancar29 wrote: »

Heres my 2 cents on tomorrows front.

Looks like a good portion of the country will see some settling snow but as its a weak front it won't cause too much disruption, certainly has been heavier more localised falls in recent weeks.


Theta-E values look good currently for full snow down to low levels however 1c up and it'll be wet snow/mess for many.


So why are we looking at a fairly weak amount? Well If we look at the wider picture we can see that the pressure gradient is fairly weak which leads to less forcing.


Associated lapse rates then due to the small temperature gradient at t500 are also quite low.



So overall, alot will see some snow tomorrow night with a nice dusting for many. Nothing to cause alarm IMO. Best for both snow bunnies and people who are worrying about work issues.

Your image file links appear to be broken ...

highdef

Iancar29 wrote: »

Heres my 2 cents on tomorrows front.

Looks like a good portion of the country will see some settling snow but as its a weak front it won't cause too much disruption, certainly has been heavier more localised falls in recent weeks.


Theta-E values look good currently for full snow down to low levels however 1c up and it'll be wet snow/mess for many.


So why are we looking at a fairly weak amount? Well If we look at the wider picture we can see that the pressure gradient is fairly weak which leads to less forcing.


Associated lapse rates then due to the small temperature gradient at t500 are also quite low.



So overall, alot will see some snow tomorrow night with a nice dusting for many. Nothing to cause alarm IMO. Best for both snow bunnies and people who are worrying about work issues.

Do you reckon elevation will be a benefactor for this event? If so, for the Eastern half of the country where snow is most likely, what sort of elevation would you say it would be best to be above to give a more certain chance of (lying) snow?

Iancar29

highdef wrote: »

Do you reckon elevation will be a benefactor for this event? If so, for the Eastern half of the country where snow is most likely, what sort of elevation would you say it would be best to be above to give a more certain chance of (lying) snow?

150m and you should be definitely seeing settling snow from the get-go. Elsewhere might have a slight delay as like a few weeks ago

highdef

Iancar29 wrote: »

150m and you should be definitely seeing settling snow from the get-go. Elsewhere might have a slight delay as like a few weeks ago

I should be able to verify on Tuesday morning. Hill beside me is just under 150m and a road goes over the highest point. I'm just below 90m so could be a slushy mess although the local roads are quiet so less disturbance from traffic. We'll be an interesting start to day, in any case. Location is North Kildare, near the Meath border, 40km West of Dublin city centre

patneve2

Reckon I could get an inch or a little more out of this. Wind direction is favourable so coastal areas will be less penalised compared to the usual setup of SE or E winds that so often screw it up for me. Areas more inland and at a certain height really should get 2 inches or more. IMO crucial is the intensity of ppn when the wind switches to the NW bringing in the PM mass; hopefully it will be moderate at times.

The Thursday/Friday event is also starting to look good on the GFS with appreciable amounts of precip over the whole country. Will have to keep a closer eye on that one.

Meteorite58

Looks more and more like a very weak front. Will get snow but small amounts more then likely IMO. In my own locality around Tralee maybe a few snow showers Tues Morning 05.00-09.00 perhaps .

Meteorite58

Euro Swiss High Res model






I would think this should say cm not mm

ninebeanrows

Latest HIRLAM a bit of an improvement intensity wise

Giving a good 4-5 hrs of light/occasionally mod snow across Leinster, including Greater Dublin

Donegal Storm

Arome..




Worth noting that this is showing snow precipitation totals rather than lying snow

Villain

I’d love to climb Lug on Tuesday becuause there is already some nice drifts on it.

I took these today with some light snow falling for an hour while I went up.

https://twitter.com/carlowweather/status/960148664093114368

Nettle Soup

My read is that Galway will get no snow between now and Wednesday. Correct assumption?

ninebeanrows

I can confirm even Harmonie showing snow - however intensity ain't amazing. Showing 3-4hr of light snow in Greater Dublin though so if that's on the deck on Tuesday morning will cause some hassle.

km79

Nettle Soup wrote: »

My read is that Galway will get no snow between now and Wednesday. Correct assumption?

Looks wonderfully dry alright

squarecircles

Nettle Soup wrote: »

My read is that Galway will get no snow between now and Wednesday. Correct assumption?

Pretty accurate assumption,
Perhaps some residual snow showers following on Tuesday,
A milder interlude on wednesday
Another front from the northwest on Thursday/friday but again this looks like being rain also in western areas.While the weekend looks like another mild sector crossing the country.Pretty dissapointing given the depth of cold to our east and the usually cold upper air temperatures over the north Atlantic.The two seemed to cancel each other out over Ireland,you couldn't write it.

ninebeanrows

Harmonie just showing 3-5mm of precip off front across Leinster

2mm in Dub city centre

10mm on Wicklow mtns

Gaoth Laidir

Meteorite58 wrote: »

I would think this should say cm not mm

That shows the total liquid water-equivalent of precipitation that fell as snow, so mm is correct. Multiply that by about 5 for very wet snow or about 40 for very dry, fluffy snow and that will be the total new snow depth in cm.

Gaoth Laidir

Weathercheck wrote: »

Harmonie just showing 3-5mm of precip off front across Leinster

2mm in Dub city centre

10mm on Wicklow mtns

Pretty low totals alright. This will be no blizzard by any means, but I'm more hopeful of seeing some proper dry snow for a while from this rather than the other wet excuse for snow that we've got so far. A couple of cm on my car Tuesday morning will be about it I reckon, but I'd expect stuff to get slushy later as dewpoints rise again from the west.

Villain

Weathercheck wrote: »

Harmonie just showing 3-5mm of precip off front across Leinster

2mm in Dub city centre

10mm on Wicklow mtns

Harmonie looks good for Northwest Tuesday evening though!

nacho libre

gozunda wrote: »

Inspiring? That forecast us enough to fxk my routine and plans from Tuesday morning onwards. If the forecast gets worse then it's not going to pretty with regard to work and travel around here ...

Will someone maybe update the thread title to show update thanks.

Worse?
I'd be hoping it gets better - more snow "depositions" for all:D

pad199207

I’d say West Wicklow will be the sweet spot for the snow. Blessington Area etc

typhoony

Usually by this time of year we'd be writing off winter, hasn't been many below average temps for the month of February for quite some years, I can remember some below average march and April. GFS keeps us well below average up until the end of February with plenty of opportunities for small to moderate dispositions.

nacho libre

squarecircles wrote: »

Pretty accurate assumption,
Perhaps some residual snow showers following on Tuesday,
A milder interlude on wednesday
Another front from the northwest on Thursday/friday but again this looks like being rain also in western areas.While the weekend looks like another mild sector crossing the country.Pretty dissapointing given the depth of cold to our east and the usually cold upper air temperatures over the north Atlantic.The two seemed to cancel each other out over Ireland,you couldn't write it.

Yes the problem is our old friend mr vortex. The cold from the north west is actually a hindrance this time. If it was a straight battle between milder altantic air and a cold continental feed we might be dealing with a more active front on Monday. It will be good to see some snow this week, but we snow lovers are greedy, we want an epic snow fall before the winter is out- something to tell future generations about. Perhaps, courtesy of the stratospheric warming event, it will happen before winters end!

highdef

Gaoth Laidir wrote: »

That shows the total liquid water-equivalent of precipitation that fell as snow, so mm is correct. Multiply that by about 5 for very wet snow or about 40 for very dry, fluffy snow and that will be the total new snow depth in cm.

So how dry do you reckon the snow will be? I'm reckoning dry, especially in areas with a little bit of height and also away from urban areas but still not really really dry snow. Should I multiply the expected liquid precipitation totals by about 10 or so, for this event? So 5mm of precipitation would give in our around 5cm of even snow?

sryanbruen

typhoony wrote: »

Usually by this time of year we'd be writing off winter, hasn't been many below average temps for the month of February for quite some years, I can remember some below average march and April. GFS keeps us well below average up until the end of February with plenty of opportunities for small to moderate dispositions.

Why would you be writing off the Winter at this time of the year? February is far more favourable for snow than November or December.

nacho libre

sryanbruen wrote: »

Why would you be writing off the Winter at this time of the year? February is far more favourable for snow than November or December.

Exactly.

Most Irish farmers will tell you, February is the optimum month for snow in this country. It certainly was when I was growing up.

Periscal

pad199207 wrote: »

I’d say West Wicklow will be the sweet spot for the snow. Blessington Area etc

Pad, fingers crossed, I am in Hollywood village, just 10km south of Blessington,our estate is at 195 m.asl, precipitation from west generally intensifies as it hits Kildare,Wicklow border, for once we can benefit from it, will certainly be reporting on Tuesday morning about the situation here, I am a keen follower of other weather forums for many years now, just dont post here to much on boards.ie

ninebeanrows

Dry snow can hit ratios if 20:1. But at sea level let's just be happy if we get 10:1 ratio