169m - 555ft
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!
Google streetview indicates height I think.
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.
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.
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..
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)
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.
Whats the likelihood of it snowing in Letterkenny?
Any snow likely for south Dublin, I'd love abit of snow
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".
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.