Greenland Express: Snow showers possible from Monday night

Rougies

Last March had a quite similar setup in terms of 850 temps and 500-1000 thickness.

Here's the thread: https://www.boards.ie/vbulletin/showthread.php?t=2057719262

Some areas did quite well for late March.


To quote Gonzo:

Gonzo wrote: »

it's kinda depressing we are getting this now, not 2 months ago. Hopefully there won't be many showers.

It's 2 months ago now this time! :pac:

Mountainsandh

Longing wrote: »

Not sure. Was looking for survey map online to see heights. But cannot find one.

Google streetview indicates height I think.

Oneiric 3

Rougies wrote: »

Last March had a quite similar setup in terms of 850 temps and 500-1000 thickness.

Here's the thread: https://www.boards.ie/vbulletin/showthread.php?t=2057719262

Some areas did quite well for late March.


To quote Gonzo:



It's 2 months ago now this time! :pac:

Ironically, it is probably easier to get snow falling in March from this set up than in January due to the fact that cooler air masses tend to be drier at that time of year.

Can't remember that particular event at all, so it must have been a non-event for here.

M.T. Cranium

These boundary runners are good for making the most of marginal thickness and upper temps, better than any maritime flow would be anyway.

The GFS event is a lot more developed than other models, that's the difference I will be looking to find reductions, as in a separate circulation not just a trough moving along, all those do usually is to back the flow and turn it too mild to snow except on top of hills.

This winter has a long way to go, time for a more substantial shift in the circulation allowing blocking highs to develop, we are well overdue for such developments.

Donegal Storm

nacho libre wrote: »

I must say i miss those winter nights too, the flash lightning way off in distance after a hefty shower. Winter 2009 was a stand out year too, as i saw thunder snow and lighting for the first time. It was an incredible sight.

December 2011 is the last decent spell of real unstable polar westerlies we had, plenty of thundery hail squalls all through the first half of the month and a few nice storms to boot.

Synoptics not too dissimilar to the upcoming spell as it happens though far more intense..

Oneiric 3

Oneiric 3 wrote: »

Ironically, it is probably easier to get snow falling in March from this set up than in January due to the fact that cooler air masses tend to be drier at that time of year.

Just to illustrate this, this graph shows the 7 day running mean relative humidity (Rh)values for the 'IMT' region* for the Jan - Mar period for the since 2007.



A clear downward trend becomes apparent from mid to late Feb. How this would correlate with Td values I don't know, as we tend to see a small rise in daily temps from about this period also. Will work this out sometime.

Data from Met Éireann / Ogimet.
* based on an 11 station mean.

Rougies

Oneiric 3 wrote: »

Just to illustrate this, this graph shows the 7 day running mean relative humidity (Rh)values for the 'IMT' region* for the Jan - Mar period for the since 2007.



A clear downward trend becomes apparent from mid to late Feb. How this would correlate with Td values I don't know, as we tend to see a small rise in daily temps from about this period also. Will work this out sometime.

Data from Met Éireann / Ogimet.
* based on an 11 station mean.

I would hazard a guess it's due to SST's hitting their lowest point late winter. Less evaporation = lower humidity = lower dps

Temp rise could correlate with less evaporation/humidity = less cloud (at a time of year when sun is getting stronger)

Oneiric 3

Rougies wrote: »

I would hazard a guess it's due to SST's hitting their lowest point late winter. Less evaporation = lower humidity = lower dps

Temp rise could correlate with less evaporation/humidity = less cloud (at a time of year when sun is getting stronger)

I thought SSTs tend to be at their coolest around early April, owing to a sort of 'lag effect'. Not actually sure of this myself.

lillielad

Whats the likelihood of it snowing in Letterkenny?

highdef

lillielad wrote: »

Whats the likelihood of it snowing in Letterkenny?

Almost certain

Daz9718

highdef wrote: »

Almost certain

Any snow likely for south Dublin, I'd love abit of snow

Rougies

Oneiric 3 wrote: »

I thought SSTs tend to be at their coolest around early April, owing to a sort of 'lag effect'. Not actually sure of this myself.

True, around early April for the Irish Sea anyway, I'm not sure about the north Atlantic area in question either but it's probably similar and maybe even later in the year minimums. I should've said "lower SSTs later in winter".

M.T. Cranium

Both the GFS and ECM 00z runs have now converged on a new solution for late Wednesday, which is to take this boundary low further north and interrupt the cold spell briefly, so now they would suggest Tuesday and Thursday are the coldest days with Wednesday briefly milder again, although potentially very windy by evening.

I am not just going to buy into this without reservations as the low they are developing does not even exist yet, it would be a new feature around Sunday on a front east of the U.S. mainland. This could keep changing to different solutions, the only surprise here is that the two models got almost exactly the same position and central pressure for the low (Donegal Bay and around 970 mbs).

This is a volatile pattern that any relatively small low could exploit to produce a major windstorm event, so that needs to be kept in mind as much as any snowfall issues.

sryanbruen

Oneiric 3 wrote: »

Ironically, it is probably easier to get snow falling in March from this set up than in January due to the fact that cooler air masses tend to be drier at that time of year.

Can't remember that particular event at all, so it must have been a non-event for here.

That was a horrible spell of weather for me with nearly 30mm of rain on the 22nd along with a maximum of just 4.6c under all that rain. That's all I remember from it apart from some mentioning snow showers, such as the BBC:

sryanbruen

Gaoth Laidir wrote: »

Nice accumulations in that photo

Looking at hourly reports for that day, Dublin Airport reported rain, sleet and hail, with two light snow showers that night, while Casement reported rain, with two reports of snow in the late afternoon. No accumulations at either station.

To me, that is not what I would call a snow event. Rain and sleet turning to brief wet snow that doesn't accumulate is more a nuisance than something to look forward to. That's not what I'm talking about when I say 516 dam, etc.

Yeah, it's far from a snow event :P, just a few showers and flakes.

Elmer Blooker

The low keeps getting pushed north with every run.
I keep saying over and over that we have to get rid of that Azores. The ECM also has it further north. Disappointing charts this morning.

fraxinus1

Elmer Blooker wrote: »

The low keeps getting pushed north with every run.
I keep saying over and over that we have to get rid of that Azores. The ECM also has it further north. Disappointing charts this morning.

It’s all falling apart. I knew it was to good to be true. I think I’ll go to Dublin for the few days so. Was going to postpone so as not to miss out but this is increasingly looking like a non event in snow terms.

snowstorm445

Outlook still looks very wintry for next week, going by some runs even beyond that. A possible milder blip in the middle of the week (depends on where that low is tracked for, as we saw with the slider scenarios they can change considerably from run to run). Unwarranted pessimism on here this morning.

Donegal Storm

First hi res charts showing brief snow accumulation in the usual high ground NW areas

munsterlegend

Donegal Storm wrote: »

First hi res charts showing brief snow accumulation in the usual high ground NW areas


Those charts are not promising save for the north west. It looks pretty windy for Thursday but that's for another thread.

Gonzo

Mod Note: Off topic posts deleted. This is a discussion about next week's potential cold event. NO more negative comments or insults towards other members. Keep all posts informative and friendly.

JCX BXC

Latest ME forecast:

Met Eireann wrote:

TUESDAY & WEDNESDAY: Very cold, windy and showery days. Many of the showers will be wintry with falls of sleet and snow expected especially in western and northern counties, where some accumulations are likely, hail and isolated thunderstorms in places also. Gale force west to northwest winds with severe gusts especially in parts of the west and north. Very high seas along Atlantic coasts with the risk of coastal flooding. Highest temperatures of 3 to 6 degrees Celsius and feeling even colder with the wind chill. Night time values of -1 to +2 degree Celsius with frost and icy stretches in sheltered areas and near wintry showers.

Nothing too shabby about that.

Captain Snow

AWESOME:)

Gaoth Laidir

Captain Snow wrote: »

AWESOME:)

Looks good on the GFS alright




But then the ECM...

Gaoth Laidir

I like the look of the ECM for the northwest on Wednesday evening though.

George Sunsnow

Captain Snow wrote: »

AWESOME:)

Just a word of caution on gfs snow maps,they have difficulty with terrain,so if somewhere has a hill,they give the hills weather to the low ground aswell
Also they have snow turning to sleet in those showers as they hit the opposite coast which simply does not make sense in a land breeze
I’ll also add the rain that turns to snow as it goes out to sea as also unlikely
So don’t take those for the Nirvana they suggest
Should be plenty snow in a lot of the showers though away from west coasts but even there,there will be snow

Another observation- Gonzo often mentions the difficulty these things have in moving too Far East
That’s because they don’t like moving into cold dryer air,it kills precip
This is a fast flow,a very fast flow with a long sea fetch,1000’s upon top of 1000’s km’s of temp contrast sea fetch which will make massive beefy thunder showers so I think Gonzo and even the Dublin area might have a pleasant surprise at times
Somewhere in between with the ecm maybe

dmcsweeney

Apologies for asking as I'm sure you're all sick of answering the 'will it snow here questions' but...I'm at 200m ASL between macroom and ballyvourney. What are our chances? And if so when. We've had a few settling snow events so far this winter but they've produced very little and it hasn't lasted long.
Thanks,
Dave

Iancar29

George Sunsnow wrote: »

Just a word of caution on gfs snow maps,they have difficulty with terrain,so if somewhere has a hill,they give the hills weather to the low ground aswell
Also they have snow turning to sleet in those showers as they hit the opposite coast which simply does not make sense in a land breeze
I’ll also add the rain that turns to snow as it goes out to sea as also unlikely
So don’t take those for the Nirvana they suggest
Should be plenty snow in a lot of the showers though away from west coasts but even there,there will be snow

Another observation- Gonzo often mentions the difficulty these things have in moving too Far East
That’s because they don’t like moving into cold dryer air,it kills precip
This is a fast flow,a very fast flow with a long sea fetch,1000’s upon top of 1000’s km’s of temp contrast sea fetch which will make massive beefy thunder showers so I think Gonzo and even the Dublin area might have a pleasant surprise at times
Somewhere in between with the ecm maybe

Rebelbrowser

dmcsweeney wrote: »

Apologies for asking as I'm sure you're all sick of answering the 'will it snow here questions' but...I'm at 200m ASL between macroom and ballyvourney. What are our chances? And if so when. We've had a few settling snow events so far this winter but they've produced very little and it hasn't lasted long.
Thanks,
Dave

Good chance of some settling snow at some stage from Tuesday on but no one can be more specific than that. Id say 70% chance where you are but 40% or so where I am (Cork suburb). I did recently move house and add 20 metres to my altitude so Im hoping that might make the difference!

patneve2

Best snow opportunity window for the greater Dublin area seems to be Tuesday late afternoon/evening. On current guidance I'd say 80% chance of seeing snow falling, about 30/40% chance of seeing modest accumulations. Wednesday's LP system also is fascinating, no clue on what track it will take. Hopefully it will end up a lot slacker and more to the south. Further on also looks interesting.