Much colder, wintry showers, some of snow Easter Sunday 2021 onward

Gaoth Laidir

Nqp15hhu wrote: »

I am not seeing a cap in this sounding:

It's right there, slight at 750 but strong at 650 hPa.

500 hPa temperature there only -25. Over the UK it will be -40, much more conducive for deep convection. We need >42 degrees between the surface and 500 hPa for polar lows to form.

Nqp15hhu

In February there was a rapid rise at 800mb and above, I still managed to get some snow showers. This is not the same.

Polar Lows only create warm sectors, they can stay away.

Gaoth Laidir

Nqp15hhu wrote: »

In February there was a rapid rise at 800mb and above. This is not the same.

Polar Lows only create warm sectors they can stay away.

Correct, it was much shallower back then. All I'm saying is that the -40 °C 500 hPa cold pool showing in runs earlier in the week has shifted well to the east, and with it the heaviest showers (and hence coldest downdrafts).

Gaoth Laidir

Nqp15hhu wrote: »

In February there was a rapid rise at 800mb and above, I still managed to get some snow showers. This is not the same.

Polar Lows only create warm sectors, they can stay away.

Tell that to a Norwegian fishing vessel caught in the middle of one. They're potent little feckers, with whiteout conditions in many.

Nqp15hhu

Lows almost always bring a warm sector down in through Donegal and Islay.

As I said no thanks.

Gaoth Laidir

Nqp15hhu wrote: »

Lows almost always bring a warm sector down in through Donegal and Islay.

As I said no thanks.

I'm talking about a proper Polar Low.

http://eumetrain.org/resources.html?page=1&cgry=-1&thm=Polar+Low&ctry=-1&months=-1&years=-1&author=-1&sat=-1&instr=-1&prod=-1&level=-1&recent=false&sorter=-1

Nqp15hhu

Yes it would warm and mix out the colder air.

JanuarySnowstor

Nqp15hhu wrote: »

Yes it would warm and mix out the colder air.[/QUOTE

The older folk on here know what a true polar low means.
They don't have a warm sector but a true polar low hasnt been seen for possibly 30 + years

snowstorm445

It was 26C here in Brussels mid-week and it looks like it'll be subzero with snow overnight on Monday and Tuesday. Feels more like the middle of Russia or Canada with such a huge temperature variation.

Nqp15hhu

JanuarySnowstor wrote: »

Nqp15hhu wrote: »

Yes it would warm and mix out the colder air.[/QUOTE

The older folk on here know what a true polar low means.
They don't have a warm sector but a true polar low hasnt been seen for possibly 30 + years

I have a Meteorology bachelors degree. I am quite aware as to what a Polar Low is as well.

“ A Polar Low is a meso-scale cyclone with a warm core only existing in a cold airmass at quite a distance from the polar front. ”

https://rammb.cira.colostate.edu/wmovl/vrl/tutorials/satmanu-eumetsat/satmanu/cms/pl/backgr.htm

Tyrone212

Gaoth Laidir wrote: »

The ECM and ICON were showing that eastern focus yesterday so the GFS is now picking up on it too.

Note too that 850 hPa will be around 200 m higher than it was back in the February event, so the same actual altitude amsl on Monday will be around 2 degrees warmer than at 850 hPa (-7 or -8)

I see. I never looked at the charts until today. Was just reading in here and xcweather for a quick breakdown.

pauldry

Another non event.

What a surprise.

Oscar Bravo

Massive downgrade on the Rte weather at half 9. Joanna back tracking alot on recent forecasts.

Donegal Storm

We haven't had a 'toppler' in years but back in the days where they were a relatively common feature they'd always get shunted east closer to the event. Looks like the same is happening this time

Little snowy old me

Ah well. Who wants all that cold weather in April anyway? As much as I love snow, I want it between November and the end of February. Yet more backtracking by many....

Right, as this has been downgraded, that's me done on here until later this year, unless something mega dramatic weather wise kicks off between now and then... which being Ireland, is not likely.

Adios.

Nqp15hhu

I know the pressure is high and it may be grasping at straws, but ICON does show quite a few snow showers for northern and north western parts.









There is a slight SW push of cold air on Tuesday.

Nqp15hhu

Little snowy old me wrote: »

Ah well. Who wants all that cold weather in April anyway? As much as I love snow, I want it between November and the end of February. Yet more backtracking by many....

Right, as this has been downgraded, that's me done on here until later this year, unless something mega dramatic weather wise kicks off between now and then... which being Ireland, is not likely.

Adios.

The 850 hpa temps have not been downgraded so don't be giving up hope yet.:) I think we could still get snow showers.

And i'm still questioning this sudden change at the last moment, it will be now casting. I will be watching the satellite image to see what way things are moving. Remember initially it was supposed to be mid Atlantic.

km79

Oscar Bravo wrote: »

Massive downgrade on the Rte weather at half 9. Joanna back tracking alot on recent forecasts.

Good

Nqp15hhu

Anyway, few seem to care anymore. The cold spell is still on it's way, however, as GL alluded to the upper levels beyond the 850hPa level have warmed up; this does not affect precipitation type or surface temps.

GFS 18z:

The colder air takes a little while to flow in, 10pm, sharp temp gradient still there but not as extreme:




4am:



8am, large gradient across the island, -12c in Ulster, 1c in SW Cork:



5pm Monday:





5pm Tuesday:





Sorry to be the bearer of bad news, but yes the cold spell has downgraded in intensity. It is still coming but the cold air at the surface will be restricted to Ulster with southern areas having highs as much as 7-8c, in sunshine.

Ulster does appear to have a risk of some light, potentially moderate snow showers despite the higher air pressure. This may just be graupel as in the Easterly, it's difficult to know at this stage. Highs here are predicted to be 2-4c on Monday and Tuesday.

This could all revert back tomorrow, though the risk is low sadly.

Kunta Kinte

Little snowy old me wrote: »

Ah well. Who wants all that cold weather in April anyway? As much as I love snow, I want it between November and the end of February. Yet more backtracking by many....

Right, as this has been downgraded, that's me done on here until later this year, unless something mega dramatic weather wise kicks off between now and then... which being Ireland, is not likely.

Adios.

Be careful out there.

Cluedo Monopoly

Will there be decent snow on high ground (Connemara >500m)?

Nqp15hhu

Cluedo Monopoly wrote: »

Will there be decent snow on high ground (Connemara >500m)?

Sorry, but probably not. It'll most likely be sunny there. Maybe a few graupel showers, the issue is not with the temperatures but the air pressure.

SouthWesterly

Little snowy old me wrote: »

Ah well. Who wants all that cold weather in April anyway? As much as I love snow, I want it between November and the end of February. Yet more backtracking by many....

Right, as this has been downgraded, that's me done on here until later this year, unless something mega dramatic weather wise kicks off between now and then... which being Ireland, is not likely.

Adios.

Downgrade. Great news. On with the gardening

Meteorite58

Intensity and frequency of showers look less then previously shown for Sunday night into Monday. Monday probably more showers in the Northern half and mostly in Northern coastal counties, wintry and as has been said more in the way of shallow convection, still could get a few hail showers, looking like a low risk of thunderstorm activity. Should be good bright spells the further S on Monday. Fresh and blustery winds later Sunday into Monday, strong on Northern coasts for a time, Monday fresh winds moving down from the N giving a pronounced Windchill.

Monday - Tuesday look like having more of a chance of wintry precipitation in Northern counties, perhaps snow possible but small amounts on lower levels if any I would have thought, mostly hill and Mountains.

Nqp15hhu

Meteorite58 wrote: »

Intensity and frequency of showers look less then previously shown for Sunday night into Monday. Monday probably more showers in the Northern half and mostly in Northern coastal counties, wintry and as has been said more shallow convection. Should be good bright spells the further S on Monday. Fresh and blustery winds later Sunday into Monday, strong on Northern coasts for a time, Monday fresh winds moving down from the N giving a pronounced Windchill.

Monday - Tuesday look like having more of a chance of wintry precipitation in Northern counties, perhaps snow possible but small amounts on lower levels if any I would have thought, mostly hill and Mountains.

Do you think this will be like the easterly with mostly light graupel showers, or could we have something more substantial (in terms of shower intensity?)?

Meteorite58

Nqp15hhu wrote: »

Do you think this will be like the easterly with mostly light graupel showers, or could we have something more substantial (in terms of shower intensity?)?

Not sure really. Maybe something like starting off with some rain / sleet, some light snow flurries early Monday morning and if there is a source for precipitation then could turn more wintry with more snow flurries during Monday and the models seem to be showing this. Probably a few light hail showers possible during Monday, just my layman's opinion mind you.

The models have eased off on the amount of precipitation, a lot of the weather heading more East as can be seen in the Fax chart as the HP out west muscles in. But as ever lots of unknowns and will be interesting to see the charts tomorrow and Sunday and then watching the data and reports coming in.

Matty (I think) on radio one there
Highs of 12 to 14 on tuesday
I'll take that
Wintry showers on mountains in west munster and north connaught monday
No mention of ulster

OldRio

SouthWesterly wrote: »

Downgrade. Great news. On with the gardening

Exactly. Wonderful.

Nqp15hhu

AuntySnow wrote: »

Matty (I think) on radio one there
Highs of 12 to 14 on tuesday
I'll take that
Wintry showers on mountains in west munster and north connaught monday
No mention of ulster

Not a chance.

Nqp15hhu

The cold air is still on it's way and is still as potent as initially forecast. I am using the 6Z ICON.

Freezing levels are low on Monday, about 300-400 metres in Ulster:


Very low Dew Points:


Max of 3-4c over Ulster:


Periodic snow showers, though look very light at times, sadly:



More snow on Monday night:


Tuesday warms up, freezing levels around 500 metres:


Icon has an undercutting low come through:


This has been forecasted on a few runs of ICON now.