Snow watch until Sunday 24th (N,W,SW most at risk)

redsteveireland wrote: »

Almost 22mm since this "event" started. A very dark, but mild day.

With not even the prospect of snow to look forward to, it really makes me question my decision to live in the west.

About the same amount here. Very run of the mill stuff.

Yes, the weather in the west can be overwhelmingly dreary and depressing a lot of the time, but this last year, and especially since the onset of July last, has taken it to a whole new level.

Well it looks like the precipitation will be over much of the east coast tomorrow, but it seems much more muted now the prospect it will fall as snow at any stage to low levels. What is the current thinking of board members? From a Dublin perspective I am going to say no cigar unless you in the foothills.

Villain wrote: »

Says a Spurs fan

Anyway all we need is a high pressure to park the bus Mourinho style around the mid Atlantic for a while and we will all be happy.

Weather Advisory for Ireland

Turning colder from Wednesday with weather conditions becoming increasingly wintry for the rest of the week. Risk of frost and icy conditions, with falls of sleet or snow at times.

Valid: 00:00 Wednesday 20/01/2021 to 23:59 Sunday 24/01/2021

Issued: 14:00 Tuesday 19/01/2021

Nqp15hhu wrote: »

Temperatures appear to be around 3c in Inishowen, not sure if that is a cooling or not. Still 4c here. Not sure if I should drive to 400 metres or not.

A better chance later on I think. Keep an eye on the temperature and the radar for greens/pink.

Tonight
Outbreaks of rain will continue in many areas tonight, turning to sleet or snow at times over high ground in Ulster. Rain may turn heavy in southern coastal counties before dawn. Holding mild in the south for much of the night, however much colder air to the north with lowest temperatures of 0 to 4 degrees will slowly sink southwards overnight with some frost forming. Fresh southwest breezes will become light northerly.

Tomorrow
On Wednesday morning, rain will become confined to the east and south where it may be heavy for a time near southeastern coasts. It will become brighter across the west and north with sunny spells and scattered showers, some wintry. Remaining cloudy in the east as rain lingers in Leinster, turning to sleet or snow at times in the afternoon. Highest temperatures of 3 to 6 degrees with a moderate northwest breeze.

I would say the chances for snow in Dublin and populated areas of Kildare and Laois is something like one in three, the chances more like three in four for snow above 250m and nearly certain above 400m.

Models are still struggling with details on this complex storm (which becomes Cristoph mainly for Britain on Thursday).

Several including Arpege and Hirlam show low pressure deepening west of Scotland eventually, with the Cristoph low weaker than on other guidance (located east of Newcastle England).

The GFS and GEM indicate only one low consolidating and that one in the North Sea, just cyclonic flow from northwest into Ulster, whereas the other models would suggest more of a westerly flow with greater trough enhancement.

Not sure which is better for snow prospects by Wed night or Thursday in Ulster, as one has more energy and the other has colder air. But would suggest there should be at least some snowfalls down to 150m or so in Ulster.

Getting back to the Dublin snow potential, that seems to depend on whether or not the back edge of this developing event will be both (a) moist enough and (b) cold enough for snow. There's a scenario where there's only drizzle and not even much rain in that stage, and another scenario where it keeps raining until near the end where it mixes but melts on contact.

I think that latter option is the most likely outcome but can't rule out a better option with a nice 3-5 cm snow cover at the end of the rainfall. Thursday should be cold enough that any wintry showers have nearly equal chances of being hail, sleet or snow.

With the range of uncertainty on Cristoph, there are still solutions buried in the mix which would see that low bombing out a bit early and that might be a good scenario for Ireland to see more snow than expected. Most guidance waits until the low is over the North Sea before really developing the circulation, but I could see where it might start bombing out as it crosses the Pennines (rather used to mountain wave development around here).

Nqp15hhu wrote: »

Pure rain and 1c at 410 metres! There is no way it’s going to snow anywhere else!

Awful! The freezing level must be really high.

https://streamable.com/1zkqgc

It was at 1563 m amsl at Castor Bay at 12Z.