Cold Spell - Feb 7th to 13th 2021 - Technical Discussion

Gaoth Laidir

munsterlegend wrote: »

Are those tafs not compiled by met Éireann? I suppose Cork airport is close to coast if not high enough up.

Yes, by aviation forecasters in Shannon.

JCX BXC wrote: »

I've always found the TAF's interestingly conservative. Perhaps it's just me, but I've noticed a definite decline in quality from them since Air Traffic collapsed, it's as if they're just thrown together.

Michelle Dillion used to be one of those forecasters, so maybe things went downhill since she left! :pac:

But yes, compared to the UK ones for the North, the Met Éireann TAFs alway err on the side of caution, I find.

bazlers

Nqp15hhu wrote: »

It’s centimetres not inches.

Its inches

Meteorite58

ECM 12Z Widespread snow if somewhat light for most. ICON-EU Flash Hi Res probably a more accurate snow distribution.

The West looking like getting more wintry precipitation / snow on the latest runs all right.

Gaoth Laidir

Here is said 15Z ICON Flash. A slight downgrade in intensity compared to the 09Z.

redsteveireland

Nqp15hhu wrote: »

It’s centimetres not inches.

It's inches as it is set to American by default if you follow that link.

justy182

Nqp15hhu wrote: »

It’s centimetres not inches.

Weather.us is in inches (in) looks like to me.

Meteorite58

Wind a factor tomorrow, would make for difficult driving conditions with snow swirling around.





Bitter cold wind-chill tomorrow.

TTLF

Gaoth Laidir wrote: »

Here is said 15Z ICON Flash. A slight downgrade in intensity compared to the 09Z.

Seems to be a lot of scatter with this still, the general precipitation main areas seem to be nailed, S, SE and E for a time, but the timing on each model is somewhat vastly different...

See there on that 15Z, we start getting the front in Dublin by 5pm, yet the MÉ HAROME model has it to us by 11pm... It could be any time between that it could start. Still some model watching to go, but it's looking like it's firming up anyway!

Does that 15Z go beyond to friday night? or is it too far away for now.

Cheers :pac::D

Meteorite58

Does that 15Z go beyond to friday night? or is it too far away for now.

No, It is just a 24 hr model.

Donegal Ken

Latest UKV model animation for tomorrow snowfall.

https://mobile.twitter.com/DonegalWeatherC/status/1359582324363509761

Gaoth Laidir

Meteorite58 wrote: »

No, It is just a 24 hr model.

30 hours

Meteorite58

AROME's current take on it, chart is for cumulative snow. hail, graupel and doesn't take into account melt or what is washed out, looking very wet along the South coast.

Looking at the WRF and it is showing mostly higher elevation snow and very light in general at ground level.

GFS in general quite light in most places apart from higher elevations.

Gaoth Laidir

12Z ECMWF simulated radar from now to Saturday night. Really reduces to light intensity overnight tomorrow and Friday morning. Just a centimetre ot two at best for the a lot of the midlands and northern Leinster. The ICON Flash would seem similar.

Meteorite58

Gaoth Laidir wrote: »

30 hours

Whoops....


https://meteologix.com/ie

European HD Flash (ICON-EU) (intermediate deadlines, 1 day)
This product displays output from a special model that can adapt to rapidly changing weather situations. The model can be run every three hours to provide the most updated information both to forecasters and to you. It is run at a high resolution but only for Europe and it only goes out 30 hours into the future.

ninebeanrows

Any snow in Dundalk tonight?

DOCARCH

ninebeanrows wrote: »

Any snow in Dundalk tonight?

You tell us?

Tyrone212

Donegal Ken wrote: »

Latest UKV model animation for tomorrow snowfall.

https://mobile.twitter.com/DonegalWeatherC/status/1359582324363509761

How well does UKV perform? I've only noticed it recently. And on that one occasion it was a good bit off.

derekon

Gaoth Laidir wrote: »

12Z ECMWF simulated radar from now to Saturday night. Really reduces to light intensity overnight tomorrow and Friday morning. Just a centimetre ot two at best for the a lot of the midlands and northern Leinster. The ICON Flash would seem similar.

1cm or 2cm? This is the “significant” snowfall that was flagged by Met Éireann last week?

Outrageous altogether that it has come down to a bit of snizzle tomorrow night!

GL, thank you for your posts. They make horrific reading for snow lovers but you are only saying it as it is.

Do you see any strong potential for snow in Leinster on Friday night?

When I say “snow”, I don’t mean snizzle and I mean something above the 1cm mark, which is paltry.

Thanks

D

Calibos

My expectations remain rock bottom based on those precipitation animations for Coastal Wicklow. A cm or two of a dusting by Friday Morning thats melted by noon at best. I don't trust any of the numbers as its likely that the pixel size issue talked about earlier will mean the higher amounts in the Wicklow mountains appear to cover Coastal Wicklow but in reality the precipitation will be light near the coast as it evaporates to nothing in that dry SE'rly flow by the time it gets this far north.

ninebeanrows

DOCARCH wrote: »

You tell us?

Apologies, posting in wrong thread...radar says yes but no obs! if there is nothing there, those crumbles on the radar to the east of Lambay definitely won't amount to much:P

noobsnow95

I noticed that on a lot of the precipitation charts and in general limerick City and central Limerick tends to show very little in terms of accumulations compared to west and east limerick. Does the Shannon have a big impact on this or would the lower altitude be the main reason? Would i be right to suggest that Limerick City will receive very little in terms of lying snow tomorrow and a quick turn to sleet in early afternoon?

Meteorite58

So after taking in all the models I am thinking ( just my opinion out of an interest ) it is perhaps going to snow lightly in general 1 to 3 cm or thereabouts, patchy, a few areas could get 5cm or so, good coatings on high ground and inland hilly terrain of up around 10 cm or so. Windy with a lot of snow and wintry precipitation swirling about and bitter cold.

Initially quite wintry in Southern areas and turning increasingly to sleet and rain as the day progresses more so towards coastal areas ( will stay very wet here for much of the weekend leading to possible floods )



Temperatures rising slowly in the SW into Fri, elsewhere widespread frosts or close to freezing later Thursday night into Fri, a lot of the country staying cold on Fri away from the SW. Thinking there could be lying snow away from coasts into early Friday especially hilly terrain. Rain on Fri should take care of snow left in most areas apart from the North Midlands perhaps, NE and perhaps parts of the E where it looks like getting wintry again and possibly turning to snow. Models currently showing the possibility of a good dump of snow in N Leinster , North Midlands perhaps and Ulster late Fri and more so into early Sat, following rain later Sat and Sun could wash this out fairly quickly.

Looking quite windy at times over the weekend, SE to S and SW on Sunday, could see 12 or 13C by Sunday afternoon.

YanSno

As mentioned days ago that south easterly dry air will weaken and dissipate the precipitation as it moves up along the country. Most models are leaning towards very light and patchy precipitation, 1cm - 5cm along south, south east, Midlands and 1cm - 2cm east that if the band even makes it that far east which am still in doubt. I'm bit more confident about Friday night into Saturday morning along the eastern half of the country, all parameters seems to be good for snow. Tomorrow night we should have a better idea how things will evolve for the weekend.

pad199207

I’ve now given in completely to the Wicklow mountain shadow

Not expecting anything here tomorrow

ZeroSum76

Meteorite58 wrote: »

So after taking in all the models I am thinking ( just my opinion out of an interest ) it is perhaps going to snow lightly in general 1 to 3 cm or thereabouts, patchy, a few areas could get 5cm or so, good coatings on high ground and inland hilly terrain of up around 10 cm or so. Windy with a lot of snow and wintry precipitation swirling about and bitter cold.

Thanks for the summary. That would do nicely if it panned out. I hope everyone gets something! I'd take 2cm at this stage !

Darc19

derekon wrote: »

1cm or 2cm? This is the “significant” snowfall that was flagged by Met Éireann last week?


D

6 days ago you said


"Met Éireann just confirming Ireland shouldn’t be too impacted by snow. The UK will take the brunt of it"

So in effect, met eireann were spot on.

Oneiric 3

pad199207 wrote: »

I’ve now given in completely to the Wicklow mountain shadow

Not expecting anything here tomorrow

You live in south Dublin I think, so you never know, a big eddy might form north of the Wicklow Mts and swirl snow back your way.

Davaeo09

Slightly annoyed at myself for getting carried away with my beliefs the Inland South East would do better tomorrow. But no, it looks like those that already had some, get more (Thursday night) and once again I am left cursing my luck in Kilkenny.

Gaoth Laidir

derekon wrote: »

1cm or 2cm? This is the “significant” snowfall that was flagged by Met Éireann last week?

Outrageous altogether that it has come down to a bit of snizzle tomorrow night!

GL, thank you for your posts. They make horrific reading for snow lovers but you are only saying it as it is.

Do you see any strong potential for snow in Leinster on Friday night?

When I say “snow”, I don’t mean snizzle and I mean something above the 1cm mark, which is paltry.

Thanks

D

I reckon we'll see that Friday night front stall a bit or at least be slower as the cold air pushes back westwards. I wouldn't be surprised to see this reflected in overnight models. If that does happen then maybe we could get a better stab at some actual accumulations instead of dustings.

It's all about the finer details now, but we're lacking a lot of upper data from aircraft so it's not as clear as it probably would have been back in 2018. I would like to have seen an 18Z balloon launch from Valentia today but they're still at the two per day.

Humberto Salazar

I don't know if there is a snow shadow in Offaly but I'm sure it'll work tomorrow.