Prelude to Cold Weather/Snow - Sun 25th Feb (Onwards)

pad199207

I said there would be 20 pages on this thread by 21:00 tonight. Its 49...

John.Icy

nacho libre wrote: »

Wasn't there - 15 upper air on the 16th of December 2010? Or am I mistaken? Anyway we don't need wholly impressive uppers when it is coming from a landmass that is already frigid.

It may not be what Syran was referencing but during the initial Easterly spell of say ~25thNov-5thDec, there were periods where snow fell with rather 'unimpressive' uppers (by that I'd be talking -5ish to -8). As you said, doesn't really matter with the source of it all.

Notably I remember (I think :pac:) one event in that spell, around 3/4/5th December (can't remember exactly) heavy snow fell with 850s somewhere between -2&-4. Such the depth of the cold and snowcover over us it didn't matter. Had around 12-15" in the garden coming up to that point - band moved down from the North - threw down another 3" but was a less powdery snow, so it aided in compacting the powdery stuff below into a less thick layer.

Even just thinking back it was incredible some of the intensity of the snow back then. There was a day in particular I remember, the 850s were ~-6 with much colder air due to arrive in over the Irish sea that evening. Had tonnes of heavy snow showers during daytime but it was rather wet stuff so nothing was really adding to the 2" on the ground. Went back out that evening and you could feel the change in the airmass and the snow was full on powder and unbelievably heavy. Haven't seen anything close to it since.

Not saying 2010 is coming of course - but the ingredients are definitely on the models for potential snowfall of at least similar intensity and accumulations. A single day in one of the Irish sea streamers back in 2010 was worth around 4-6" of snowfall. Only thing was with constant buffeting of winds - for every day you were under a streamer, you spent a day in the IOM shadow for your sins.

IIRC some lower parts of the East got a good 20-30cm fall from the shallow low in the Irish sea 2/3 days before Christmas?

Anyway I digress - it's a long wait for the 18z

derekon

M.T. Cranium wrote: »

I believe that was in March 2013. Some parts of eastern and southern Ireland got snow during that cold spell, but it wasn't anything to rival Dec 2010. I had a look at some charts from that period and uppers briefly got below -10 C but in any case the month is more remembered for a dry cold that persisted for about three weeks (roughly 9th to 1st of April).

Have been catching up (my sleep cycle has shifted well away from what would be appropriate to the local time zone, I just slept from 0500h to 1100h so it takes a while to review all the new data then read through the threads here and (skim mostly) NW. Looks like my prediction of 62 pages by 2100h is going to verify, I can always influence that prediction of course (by posting a lot) too bad you can't do that with a weather forecast!

My overall impression was something along the lines of very slight downgrades on GFS, not quite so apocalyptic on GEM, ECM a somewhat different route than last night, but probably equally impressive in its own way.

This is a massive outbreak and I think the larger weather services will come under increasing pressure to warn of its potential as models keep churning out roughly the same scenario run after run. That NMM animation was a good illustration of how the westward progress of the cold air is likely to accelerate and with that you get a wider spread of possible arrival times.

Thanks MT. You might confirm that one of the weather services that should issue a warning will be MET EIREANN. Please, pretty please 😋


D

Reckless Abandonment

Lumen wrote: »

I guess it depends on what you mean by "snow" and "in Dublin".

Snow at Dublin Airport
http://www.thejournal.ie/dublin-airport-snow-delays-827194-Mar2013/

Hail at Grand Canal Dock
http://www.thejournal.ie/hailstones-dublin-pictures-834987-Mar2013/

I stand corrected. But for the life me don't remember it.

sryanbruen

John.Icy wrote: »

It may not be what Syran was referencing but during the initial Easterly spell of say ~25thNov-5thDec, there were periods where snow fell with rather 'unimpressive' uppers (by that I'd be talking -5ish to -8). As you said, doesn't really matter with the source of it all.

Notably I remember (I think :pac:) one event in that spell, around 3/4/5th December (can't remember exactly) heavy snow fell with 850s somewhere between -2&-4. Such the depth of the cold and snowcover over us it didn't matter. Had around 12-15" in the garden coming up to that point - band moved down from the North - threw down another 3" but was a less powdery snow, so it aided in compacting the powdery stuff below into a less thick layer.

Even just thinking back it was incredible some of the intensity of the snow back then. There was a day in particular I remember, the 850s were ~-6 with much colder air due to arrive in over the Irish sea that evening. Had tonnes of heavy snow showers during daytime but it was rather wet stuff so nothing was really adding to the 2" on the ground. Went back out that evening and you could feel the change in the airmass and the snow was full on powder and unbelievably heavy. Haven't seen anything close to it since.

Not saying 2010 is coming of course - but the ingredients are definitely on the models for potential snowfall of at least similar intensity and accumulations. A single day in one of the Irish sea streamers back in 2010 was worth around 4-6" of snowfall. Only thing was with constant buffeting of winds - for every day you were under a streamer, you spent a day in the IOM shadow for your sins.

IIRC some lower parts of the East got a good 20-30cm fall from the shallow low in the Irish sea 2/3 days before Christmas?

Anyway I digress - it's a long wait for the 18z

They were more impressive than the latter December 2010 ones, much around -10c.

Saganist

sryanbruen wrote: »

Yeah, the only time I woke up to lying snow that March regardless of the snow showers and how cold it was (it was down to persistence than extremes, it's a very forgettable March in terms of extremes) was the 27th which had my neighbourhood covered in white courtesy of the snow showers and severe frost.

Funnily enough, it was the 27th that stuck in my mind that March.

Mantis Toboggan

Even yr now reporting temperatures as low as - 4 next week, this could get quite chilly.

sideswipe

pad199207 wrote: »

I said there would be 20 pages on this thread by 21:00 tonight. Its 49...

Well there is about 19 pages commenting on how many pages there are so good guess;)

sryanbruen

Reckless Abandonment wrote: »

I stand corrected. But for the life me don't remember it.

Can't blame ya honestly 'cause as I said above, the only morning I had lying snow was 27th March. Other than that, it was snow showers through the day. Although as a 12 year old in school at the time, it was a bit strange seeing heavy snow showers on the 19th/20th March in school.

TheMilkyPirate

Whatever happens the next week will be a fantastic time to have an interest in the weather, Will be great to watch it develop

highdef

pad199207 wrote: »

I said there would be 20 pages on this thread by 21:00 tonight. Its 49...

I'm on page 19

Snowbiee21

62 pages mt 🙂

snowstorm445

I remember March 2013 in Cork brought a fair number of snow showers on one particular day towards the end of the month, some of which were very heavy and impressive, but none of it stuck and during the night they all died away before they reached us. Meanwhile up the road, Waterford got pasted with streamers and woke up to about 7-8cm if I remember correctly.

MissMoc

The weather on my phone showed snow for next Tuesday and Thursday- both gone now

Snowbiee21

MissMoc wrote: »

The weather on my phone showed snow for next Tuesday and Thursday- both gone now

Would pay zero attention to that .

mickger844posts

snowstorm445 wrote: »

I remember March 2013 in Cork brought a fair number of snow showers on one particular day towards the end of the month, some of which were very heavy and impressive, but none of it stuck and during the night they all died away before they reached us. Meanwhile up the road, Waterford got pasted with streamers and woke up to about 7-8cm if I remember correctly.

Yeah we got a right pasting that night. Dug out this video i took on the 11th March 2013. It will wet the appetite for next week

sryanbruen

MissMoc wrote: »

The weather on my phone showed snow for next Tuesday and Thursday- both gone now

Like I said earlier, weather apps are an abomination. Stay far away from them.

Doltanian

Over 500 hundred sheep have moved to the lower parts of the mountains here in Kerry all heaviliy in lamb. My father who is in his late 60's came in this evening before hearing any forecast and his first thing out of him was I've an awful feeling we are going to get a heavy fall of snow. You can sense it in nature, the animals know it before our satellites tell us, he has spent his lifetime atuned to nature.

Franz Von Peppercorn

sryanbruen wrote: »

Like I said earlier, weather apps are an abomination. Stay far away from them.

They are fairly accurate within a few days I find.

And they must be interpreting the latest runs somehow.

sryanbruen

Franz Von Peppercorn wrote: »

They are fairly accurate within a few days I find.

And they must be interpreting the latest runs somehow.

Within my lifetime, they've been 100% inaccurate. I can tell you millions of times where they've said snow for me and I've not seen a flake. Same with rain or cloudy skies.

I much much prefer looking at the charts and doing my own interpretations or forecasts.

Pangea

The met offices thoughts on the cold spell (not sure if this was already posted)
https://www.metoffice.gov.uk/news/releases/2018/conditions-turning-colder-later-in-the-week

Reckless Abandonment

MissMoc wrote: »

The weather on my phone showed snow for next Tuesday and Thursday- both gone now

Phones fecked. Id get a new one

PukkaStukka

I was at a concert in Dublin on Monday 25th March 2013 and standing in the queue to get into the venue was the coldest I have ever been in my life, and that included skiing in the Alps! I recall no snow, just extreme bitter cold.

I was at another concert in Belfast 4 days later and it was equally as cold. There was lying snow in patches all the way from the border to Belfast. Black And Divis mountain were all plastered with snow and people I spoke to said it was the worst snowfall they'd had in well over a decade.

Youngpensioner

Reckless Abandonment wrote: »

I cant remember any snow in Dublin in 2013 .

I said almost everywhere. If memory serves me well they did.

Oscar Bravo

That'll do nicely

onmebike

She said it! Siobhán said it!

I can imagine the meeting before that forecast and the senior forecasters looking over their glasses at her and saying "Pull the trigger!"

DominoDub

Pangea wrote: »

The met offices thoughts on the cold spell (not sure if this was already posted)
https://www.metoffice.gov.uk/news/releases/2018/conditions-turning-colder-later-in-the-week

That Link has a very good explanation of Sudden Stratospheric Warming

https://www.youtube.com/watch?v=1MiUlTthSNA

sryanbruen

I never watch the weather forecasts on TV but I might for a change this coming week .

Gaoth Laidir

I'm a bit worried now about the downgrades in the ECM and GFS compared to this time last night. The chances of substantial precipitation have diminished, with QPF of only 2-4 mm through much of the east and south through next week. The depth of cold air in today's run has diminished. Plenty cold at 850 hPa but the 700 hPa temeratures are now 3-4 degrees warmer than they were showing yesterday. This would lead to shallower convection and hence lower precipitation totals. Not getting those deep saturated profiles I posted yesterday.

Still not much question as yet over type of precipitation, but with the westerly fringe of coldest air edging slightly eastwards every run I'd be concerned that any further downgrades could lead to a downward spiral. Will be checking the 00Z runs with interest.

gabeeg

Gaoth Laidir wrote: »

I'm a bit worried now about the downgrades in the ECM and GFS compared to this time last night. The chances of substantial precipitation have diminished, with QPF of only 2-4 mm through much of the east and south through next week. The depth of cold air in today's run has diminished. Plenty cold at 850 hPa but the 700 hPa temeratures are now 3-4 degrees warmer than they were showing yesterday. This would lead to shallower convection and hence lower precipitation totals. Not getting those deep saturated profiles I posted yesterday.

Still not much question as yet over type of precipitation, but with the westerly fringe of coldest air edging slightly eastwards every run I'd be concerned that any further downgrades could lead to a downward spiral. Will be checking the 00Z runs with interest.

I haven't seen them, but by all accounts the ECM precip charts are showing us buried