Cold Spell - Feb 7th to 13th 2021 - Chat

ZX7R

[Deleted User] wrote: »

The spectrum is high in this thread.

I think you should have highlighted the part of your post in brackets a bit better
Ha

Little snowy old me

Couldn't resist a wee drop in to see how everyone's doing. Deliberately stayed away for the last 24 hours as I found the roller coaster a bit much. Hoping we are starting to nail events down now.

Mimon

Gaoth Laidir wrote: »

Base reflectivity (simulated radar) and 850-hPa steering winds from 12Z tomorrow to early Thursday. Very light precipitation making some inroads towards the midlands at times as the steering flow varies from ENE Monday/Tuesday to more easterly on Wednesday.

Met Eireann not agreeing

"
Monday: Scattered wintry showers will continue to move in from the Irish Sea onto eastern and northern coasts. Bright or sunny spells developing generally and staying mainly dry elsewhere. Daytime temperatures of 1 to 3 degrees in moderate to fresh easterly winds.

Monday night: Wintry showers will become more frequent and push further inland later in the night. Very cold with clear spells and lowest temperatures of minus 3 to zero degrees with a widespread sharp frost under clearing skies. Mainly moderate easterly winds, fresh to strong in the southwest.

Tuesday: Staying very cold with temperatures through the day of plus 1 to 3 degrees in fresh easterly winds, strong on southern coasts. Wintry showers will continue to feed in from the east, affecting mainly the northeast and east with some accumulations possible. More isolated showers will reach further inland. Very cold overnight again with lowest temperatures of minus 4 to zero degrees with severe frost and ice causing hazardous conditions. Winds will ease overnight with fog developing.

Wednesday: Further wintry showers will occur through Wednesday. Daytime temperatures only reaching 2 or 3 degrees for much of the country. Light to moderate easterly winds will freshen on Atlantic coasts towards the evening as a band of rain arrives from the southwest, gradually extending into much of Munster overnight, preceded by falls of sleet and snow. Another very cold night with lowest temperatures of minus 4 to zero degrees."

The chan chan man

Gaoth Laidir wrote: »

Base reflectivity (simulated radar) and 850-hPa steering winds from 12Z tomorrow to early Thursday. Very light precipitation making some inroads towards the midlands at times as the steering flow varies from ENE Monday/Tuesday to more easterly on Wednesday.

Dumb it down for me.. does that mean it will snow or it won’t snow? The “beast from the east” as described by the examiner as a “siberian powerhouse” sounds like it will be a bit of cold rain?! Lol

jackrussel

ZX7R wrote: »

I think you should have highlighted the part of your post in brackets a bit better
Ha

They still wouldn’t have read it properly and got offended anyway

Chalkitdown147

kittyn wrote: »

I beg to differ ...... Back in 2018 the snow plough got stuck up where I am and a tractor had to pull it out

Where are you based?? I think the point being made adnauseam today is that you just can't tell where streamers, if any, are likely to land. Ninja snow too has a tendency to shows it face too

esposito

The chan chan man wrote: »

Dumb it down for me.. does that mean it will snow or it won’t snow? The “beast from the east” as described by the examiner as a “siberian powerhouse” sounds like it will be a bit of cold rain?! Lol

Light snow flurries

Mimon

The chan chan man wrote: »

Dumb it down for me.. does that mean it will snow or it won’t snow? The “beast from the east” as described by the examiner as a “siberian powerhouse” sounds like it will be a bit of cold rain?! Lol

I think he is being selective in showing the most non snow productive chart as he is on a one man crusade to dampen down the hype.

ninebeanrows

EC showing much of the substantial streamers staying north of Howth Head on this run

Humberto Salazar

A lot of those snow depth charts, if you put faith in them, show 25 to 30cm of accumulated snow for the UK Eastern side, as you would expect. But very little further west and over Ireland.

Gaoth Laidir

Mimon wrote: »

Met Eireann not agreeing

"
Monday: Scattered wintry showers will continue to move in from the Irish Sea onto eastern and northern coasts. Bright or sunny spells developing generally and staying mainly dry elsewhere. Daytime temperatures of 1 to 3 degrees in moderate to fresh easterly winds.

Monday night: Wintry showers will become more frequent and push further inland later in the night. Very cold with clear spells and lowest temperatures of minus 3 to zero degrees with a widespread sharp frost under clearing skies. Mainly moderate easterly winds, fresh to strong in the southwest.

Tuesday: Staying very cold with temperatures through the day of plus 1 to 3 degrees in fresh easterly winds, strong on southern coasts. Wintry showers will continue to feed in from the east, affecting mainly the northeast and east with some accumulations possible. More isolated showers will reach further inland. Very cold overnight again with lowest temperatures of minus 4 to zero degrees with severe frost and ice causing hazardous conditions. Winds will ease overnight with fog developing.

Wednesday: Further wintry showers will occur through Wednesday. Daytime temperatures only reaching 2 or 3 degrees for much of the country. Light to moderate easterly winds will freshen on Atlantic coasts towards the evening as a band of rain arrives from the southwest, gradually extending into much of Munster overnight, preceded by falls of sleet and snow. Another very cold night with lowest temperatures of minus 4 to zero degrees."

I think that's pretty much what my animation shows. I don't see the contradiction.

Here's my very basic heat map of highest streamer risk Monday to Wednesday.

Gonzo

GFS 12z reduces snow intensity alot from the streamers. In terms of precipitation 1 to 3mm of 'precipitation' between now and Thursday.





Stays mostly dry till Monday afternoon then some light showers drifting onto eastern coasts. A better chance of a light to semi moderate fall in places on Tuesday and the streamers die out again on Wednesday.



I still believe the models are underplaying the snowrisk a bit, expect little but we may yet end up being pleasantly surprised. We should have a better idea on Monday.

Reversal

I've noticed a few times and tonight is a good example that convective streamers tend to be kicked off by their proximity to terrain rather than inhibited by them thanks to orographic uplift.

Replaying satellite and radar returns it's clear the only real convective activity tonight is downwind of Angelsy and the Llyd Peninsula. Reverse shadow effect.

The chan chan man

The chan chan man wrote: »

Dumb it down for me.. does that mean it will snow or it won’t snow? The “beast from the east” as described by the examiner as a “siberian powerhouse” sounds like it will be a bit of cold rain?! Lol

Its a rolling snapshot today of what a simulation radar thinks of the shower situation based on.the 12z ECMWF which wouldn't be the best at this stage at guessing
The hi Res Harmonie 12 z model (Met Éireann version)tomorrow and monday will tell the tale definitely

BrandonBay86

Anyone know how to make the Isle of Man disappear for a week ?

BrandonBay86

Gonzo wrote: »

GFS 12z reduces snow intensity alot from the streamers. In terms of precipitation 1 to 3mm of 'precipitation' between now and Thursday.





Stays mostly dry till Monday afternoon then some light showers drifting onto eastern coasts. A better chance of a light to semi moderate fall in places on Tuesday and the streamers die out again on Wednesday.



I still believe the models are underplaying the snowrisk a bit, expect little but we may yet end up being pleasantly surprised. We should have a better idea on Monday.

We both know streamers are are now cast situation .

RobertKK

There were a couple of showers today in Kilkenny, one was heavy.

Usually get some snow in this situation on the high ground, so will see how it works out up to Wednesday.

Gaoth Laidir

Mimon wrote: »

I think he is being selective in showing the most non snow productive chart as he is on a one man crusade to dampen down the hype.

Gonzo

BrandonBay86 wrote: »

Anyone know how to make the Isle of Man disappear for a week ?

this time around it doesn't look like the IOM shadow is going to affect Ireland. SE parts of Northern Ireland may well be affected by it tho. The Wales shadow is a bigger issue this time around.

Oneiric 3

The chan chan man wrote: »

described by the examiner as a “siberian powerhouse”l

I think 'bunny from the baltic' would be a more apt description.

munsterlegend

Gaoth Laidir wrote: »

You can just waltz in here with scientifically verified charts we don’t like.

Gaoth Laidir

Mimon wrote: »

I think he is being selective in showing the most non snow productive chart as he is on a one man crusade to dampen down the hype.

One example of the best soundings from just off the Drogheda coast on Tuesday morning. Very shallow convection, capped by a strong subsidence inversion from around 700 hPa, with barely any CAPE for surface parcels cold enough for snow. Light sleet or snow/snow grains would likely be the most common form of precipition with this.

Zogabomb

Gaoth Laidir wrote: »

I think that's pretty much what my animation shows. I don't see the contradiction.

Here's my very basic heat map of highest streamer risk Monday to Wednesday.

I have a very unscientific question,Today, we have hit all day by showers from the Irish Sea - I could be wrong but is the wind direction today ENE?

If so, is it likely (if the wind direction doesn't change too much) that the same areas getting the rain showers today could get snow showers from Monday?

Tyrone212

Gaoth Laidir wrote: »

I know the feeling lol.

The previous chart you posted. Do you think Tory island could see some accumulations? Its only 5km long and 1km wide.

Oneiric 3

redsteveireland wrote: »

It will be cold, and nice weather for getting out doors at the very least, besides the wind chill that is.
IMO.

Wind chill feel from an easterly is far more easy to deal with than the usual chill from the west.

Can't wait for this winter to be over. While it may have been on the chilly side a lot of the time, I don't recall any notable weather event during it. Not even a lousy named lousy storm. I intend spending the spring and summer doing up the back garden and am dying to get at it at this stage.

Gaoth Laidir

Zogabomb wrote: »

I have a very unscientific question,Today, we have hit all day by showers from the Irish Sea - I could be wrong but is the wind direction today ENE?

If so, is it likely (if the wind direction doesn't change too much) that the same areas getting the rain showers today could get snow showers from Monday?

Today's showers were different to the streamers of next week and were linked to the low pressure system we've had over the past few days. Upper levels (700-500 hPa) are much colder now than they will be next week and the surface layer warmer and more moist, so today's convection was deeper in nature.

That low is moving southeastwards and those upper levels will start to warm. From late tomorrow things will reset and we'll be getting convection confined to only the very lowest levels (below 700 hPa) due to the large difference in temperature between there and the sea. It's a half-brother of what we had today.

Sounding from off the Dublin coast today.

Gaoth Laidir

Tyrone212 wrote: »

I know the feeling lol.

The previous chart you posted. Do you think Tory island could see some accumulations? Its only 5km long and 1km wide.

Very possible, but it will cast a Tory Shadow on Rockall.

Mimon

munsterlegend wrote: »

You can just waltz in here with scientifically verified charts we don’t like.

Charts are possible outcomes. As we know they have been very inaccurate in these situations plenty of times before.

You do realise that different charts often show very different outcomes so it is definitely possible to pick one to suit your slant if you were that way inclined.

munsterlegend

Mimon wrote: »

Charts are possible outcomes. As we know they have been very inaccurate in these situations plenty of times before.

You do realise that different charts often show very different outcomes so it is definitely possible to pick one to suit your slant if you were that way inclined.

I am well aware of that but I don’t think any chart shows any great streamer activity at the moment. Of course charts get it wrong and can change.

Brendan offaly

Went for a cycle along the canal outside East of Tullamore. Constant light rain or drizzle even though the rainfall radar shows very little precipitation.
Temp around 4 degrees and very light winds.
Actually felt very pleasant outside.
Milder than earlier today.
Can’t wait to see the outcome from streamers over the coming days. Best of luck to everyone looking for snow.