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

Macy0161

Kermit.de.frog wrote: »

I think snow showers are likely early tomorrow morning but very hit and miss...

Definitely tried overnight near Roundwood - a bit of white on the cars, but must have been mainly mixed at my level. It was dark when I hit the road this morning so couldn't see the tops to see if there was snow.

Wicklow Co Co have just put out an advisory to avoid the Sally Gap due to icy conditions though.

Kermit.de.frog

Gaoth Laidir wrote: »

We are now at the most westerly extent of the cold airmass from the east. From now on it will stall and then retreat back eastwards during the afternoon. Still need that cloud deck to shift later or else.

Here is a selectable chart of current wet-bulb observations. Change the time during the day to get the latest. We need it at 0.5 or below later to be fairly guaranteed of snow. A rise in dewpoint or temperature rises the wbt, and vice versa. The wbt is around 30-40% of the way between the dry bulb temperature and dewpoint.

https://weather.us/observations/great-britain/wet-bulb-temperature/20180205-0900z.html

I'm a little less enthusiastic about tonight than I was yesterday, given this cloud layer and current readings.

You can keep an eye here. I suspect it will evaporate through the afternoon.

https://en.sat24.com/en/gb/visual

Can see clear skies to my east now in Dublin.

We won't have much time to see the temperature fall after dark, so it better clear...

dacogawa

I'm quite worried about the regional forecast for Dublin on the met.ie site, not about the snow and ice more about the "time travel" aspect, has anyone had experience with snowy time travel before? also if you had anything planned for Tuesday in Dublin I'd change your arrangements



They must have snow head in there this morning...

ninebeanrows

Gaoth Laidir wrote: »

We are now at the most westerly extent of the cold airmass from the east. From now on it will stall and then retreat back eastwards during the afternoon. Still need that cloud deck to shift later or else.

Here is a selectable chart of current wet-bulb observations. Change the time during the day to get the latest. We need it at 0.5 or below later to be fairly guaranteed of snow. A rise in dewpoint or temperature rises the wbt, and vice versa. The wbt is around 30-40% of the way between the dry bulb temperature and dewpoint.

https://weather.us/observations/great-britain/wet-bulb-temperature/20180205-0900z.html

I'm a little less enthusiastic about tonight than I was yesterday, given this cloud layer and current readings.

Cold, dry air going to continue to feed into east coast until around 8pm i thought?

DPs ala HIRLAM




DPs continue to drop along the east coast.

KingBobby

dacogawa wrote: »

I'm quite worried about the regional forecast for Dublin on the met.ie site, not about the snow and ice more about the "time travel" aspect, has anyone had experience with snowy time travel before? also if you had anything planned for Tuesday in Dublin

They must have snow head in there this morning...

Tuesdays are generally over rated anyway

Kermit.de.frog

Weathercheck wrote: »

DPs continue to drop along the east coast.

Yep but i'd rather clear skies after dark in advance if only to get the ground temps down...dp -1.4c now at Howth, temp 3.3 but this will tumble once wind goes of shore.

Rebelbrowser

Isn't incredible we cant get one single "definitely snow" event. In fact in my neck of the woods, where there is a little bit of a chance of snow, I can't remember the last event we had where snow (as opposed to a risk of it) was actually forecast for here. Many years ago I suspect.

George Sunsnow

Trying to clear here near Arklow
This pic is to the south but I can also see some blue to the east
Wind very light almost calm mostly ENE

Dp Dropped but stopped dropping
Air temp now stable ish at 3.7c
Wet bulb concerning

https://twitter.com/arklowweather/status/960464274492739585

Kermit.de.frog

George Sunsnow wrote: »

Trying to clear here near Arklow
This pic is to the south but I can also see some blue to the east
Wind very light almost calm mostly ENE

Dp Dropped but stopped dropping
Air temp now stable ish at 3.7c
Wet bulb concerning

https://twitter.com/arklowweather/status/960464274492739585

The air temperature will plummet once winds go off shore this evening though.

Rebelbrowser

Gaoth Laidir wrote: »

We are now at the most westerly extent of the cold airmass from the east. From now on it will stall and then retreat back eastwards during the afternoon. Still need that cloud deck to shift later or else.

Here is a selectable chart of current wet-bulb observations. Change the time during the day to get the latest. We need it at 0.5 or below later to be fairly guaranteed of snow. A rise in dewpoint or temperature rises the wbt, and vice versa. The wbt is around 30-40% of the way between the dry bulb temperature and dewpoint.

https://weather.us/observations/great-britain/wet-bulb-temperature/20180205-0900z.html

I'm a little less enthusiastic about tonight than I was yesterday, given this cloud layer and current readings.

The latest observations on that link at 3am. Is that US time? Even if so, do you add 7 (which seems an odd number) hours as presumable 10am observations should be the most recent?

Larbre34

Rebelbrowser wrote: »

Isn't incredible we cant get one single "definitely snow" event. In fact in my neck of the woods, where there is a little bit of a chance of snow, I can't remember the last event we had where snow (as opposed to a risk of it) was actually forecast for here. Many years ago I suspect.

On an island sitting in a pool of constantly tepid water? Not really. Some seem to get indignant at the lack of our fair share of snow. Everyone should bear in mind, the occurance of snow to low levels in Ireland IS the outlier, not the other way round.

As for tonight / tomorrow, im seeing quite a bit of snizzle and clawing dankness in our future at populated levels, not too much else

Kermit.de.frog

Larbre34 wrote: »

As for tonight / tomorrow, im seeing quite a bit of snizzle and clawing dankness in our future at populated levels, not too much else

You can get an early night so.:cool:

pad199207

Dewpoint starting to take a tumble here now too.

highdef

Kermit.de.frog wrote: »

You can keep an eye here. I suspect it will evaporate through the afternoon.

https://en.sat24.com/en/gb/visual

Can see clear skies to my east now in Dublin.

We won't have much time to see the temperature fall after dark, so it better clear...

With the layer of cloud being quite stubborn to clear, would this be a good thing that it is delayed until later this afternoon. Sunshine now and for the next few hours would likely raise the temperatures a degree or two, plus there'd be a bit of ground heating too.
Would it not be better if the clearance arrived around mid afternoon, basically closer to sunset, so that temperatures are already quite cold when the sun goes down thereby allowing more of a temperature drop of both the air and the ground?

RobertKK

Some people just live in areas not favoured for snow.
Had 3 or 4 different days/snow events where there was lying snow since winter started, but that is why hill snow does be mentioned.
Most will see snow though I feel tonight. But again higher elevations always better for snow.

Kermit.de.frog

highdef wrote: »

Would it not be better if the clearance arrived around mid afternoon, basically closer to sunset, so that temperatures are already quite cold when the sun goes down thereby allowing more of a temperature drop of both the air and the ground?

Of course. Would be ideal.

I'd rather not take the punt on it though:pac:

Would prefer if it just cleared. As long as we get those ground temperatures down that's all that matters.

George Sunsnow

Suns out and sky has cleared near Arklow
Dp dropping again -2.9c
Air temp 4.2c

Kermit.de.frog

Just for western and some northerners who may miss out on the frontal stuff the snow showers are packing in tightly behind so looks like these will be in to the north and west in quick order once the front passes through. Don't be too disappointed if you miss out on the frontal element.

Villain

Harmonie:
https://twitter.com/MetEireann/status/960474063759183872

highdef

George Sunsnow wrote: »

Suns out and sky has cleared near Arklow
Dp dropping again -2.9c
Air temp 4.2c

So that's already a 0.5c increase in temperature since the sun appeared. Really hoping the cloud does not break over Dublin city for several more hours as I'd love Dublin city and suburbs to get a covering, despite the fact that I don't live in Dublin. Could be an awful commute from North Kildare tomorrow though, especially as Tuesdays are the worst day for commuting by car in Dublin. Throw snow in the mix and it's a recipe for disaster.

pad199207

highdef wrote: »

So that's already a 0.5c increase in temperature since the sun appeared. Really hoping the cloud does not break over Dublin city for several more hours as I'd love Dublin city and suburbs to get a covering, despite the fact that I don't live in Dublin. Could be an awful commute from North Kildare tomorrow though, especially as Tuesdays are the worst day for commuting by car in Dublin. Throw snow in the mix and it's a recipe for disaster.

It will be interesting to see how far inland snow will settle

George Sunsnow

highdef wrote: »

So that's already a 0.5c increase in temperature since the sun appeared. Really hoping the cloud does not break over Dublin city for several more hours as I'd love Dublin city and suburbs to get a covering, despite the fact that I don't live in Dublin. Could be an awful commute from North Kildare tomorrow though, especially as Tuesdays are the worst day for commuting by car in Dublin. Throw snow in the mix and it's a recipe for disaster.

4.7c now
Dp up to -1.5

Wet bulb roasting

patneve2

Reckon temps will be around 1/2C when the front arrives this evening so a brief period of sleety snow is possible, followed by full on light/moderate snow when the front gets going. Would be great to snatch a few hours of clear skies after 5pm - even a slight ground frost would be great even though I doubt that will happen. Still going for an inch of wettish snow in my location (Dalkey), more in land.

Rebelbrowser

Euro 04, which was the least enthusiastic on snow prospects is improving......

George Sunsnow

Temp up like a rocket here near Arklow since the sun came out
Now 5.7c
Wet bulb 3c
Dp now -1.3c

highdef

patneve2 wrote: »

Reckon temps will be around 1/2C when the front arrives this evening so a brief period of sleety snow is possible, followed by full on light/moderate snow when the front gets going. Would be great to snatch a few hours of clear skies after 5pm - even a slight ground frost would be great even though I doubt that will happen. Still going for an inch of wettish snow in my location (Dalkey), more in land.

I'd agree with your reckoning.....Ice could be a an issue too if there is a layer of water on surfaces first, which then freezes and gets a layer of snow on top. Could make road conditions worse than if there was just a layer of snow only.

munsterlegend

I can see now how east cork got into their warning by the skin of their teeth!

Gaoth Laidir

Weathercheck wrote: »

Cold, dry air going to continue to feed into east coast until around 8pm i thought?

DPs ala HIRLAM




DPs continue to drop along the east coast.

I was referring to the 850 temps.

http://wxcharts.eu/gifs/M7i1tecmnr.gif

The lower levels really depends on radiative cooling, which will be minimised if that cloud persists.

Gaoth Laidir

Rebelbrowser wrote: »

The latest observations on that link at 3am. Is that US time? Even if so, do you add 7 (which seems an odd number) hours as presumable 10am observations should be the most recent?

I had it at Irish time. Adjust the settings to show Irish time.

torres9kop

Will it snow in Sandymount tonight or am I to near sea level. Will the Tuesday morning commute be mental or wha? Thanks