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

Funsterdelux

Kermit.de.frog wrote: »

Don't tell those Cork lads

Sacrebleu!

Squidvicious

Kermit.de.frog wrote: »

Don't tell those Cork lads

How far north east is that likely to get(from a non Cork lad😉)

Tyrone212

Gfs follows Ecm in showing paltry limited accumulations from showers next week. Slim pickings, American time.

https://weather.us/model-charts/standard/ireland/snow-depth-in/20210209-2100z.html

https://weather.us/model-charts/standard/ireland/snow-depth-in/20210210-2100z.html

lucernarian

Tyrone212 wrote: »

Gfs follows Ecm in showing paltry limited accumulations from showers next week. Slim pickings, American time.

https://weather.us/model-charts/standard/ireland/snow-depth-in/20210209-2100z.html

https://weather.us/model-charts/standard/ireland/snow-depth-in/20210210-2100z.html

It showed the same in past situations. Parts of Louth, Dublin and Wicklow reached over 40cm of snow over 3 days in November/December 2010 even though little was forecast by the global models. The short term, high resolution models were better, but they still underestimated the precipitation that fell

Rebelbrowser

Tyrone212 wrote: »

Gfs follows Ecm in showing paltry limited accumulations from showers next week. Slim pickings, American time.

https://weather.us/model-charts/standard/ireland/snow-depth-in/20210209-2100z.html

https://weather.us/model-charts/standard/ireland/snow-depth-in/20210210-2100z.html

Always the way from streamers. They showed v little precipitation in 2018 and 2010 too. Doesn't mean they won't be right this time of course.

More generally, just looking at the Icon and the low it has passing through on Tuesday, that seems like crazy model variation at this remove for 5 days time.

Tyrone212

In my experience the models usually over cook snow totals from far out more often than they don't.

JanuarySnowstor

I would think the Icon low for Tuesday isn't going to happen so best to forget about it. GFS looks good though for quite a few coastal snow showers.

Re long term this cold spell will surely put up a fight so I fully expect at least Thursday to remain bitter.
We won't get much sleep will we, yet another 4am start for most of us lol

sryanbruen

Didn't know whether to post this in FI or this 'event' thread. Interesting to hear that the in-house UK Met Office MOGREPS are showing the cold being prolonged and the lows to not successfully undercut the blocking although difficult to tell the north positioning of them with no synoptics available publicly.

Can't say I see such a "dense" anticyclonic block in the high latitudes as compared to the years named in the model output, looks all fragile to me. I still remain skeptical about this entire thing until I see something more exciting arise, Tuesday looks best day as of now to me but not expecting much.

We know what model runs have been like throughout this polarcoaster though.

https://twitter.com/EssexWeather/status/1357458451308417024

Nqp15hhu

I agree. This looks to be quite an intense pool of cold air that flows past the western coast 300-500 miles.

I don’t see that breaking down that quickly. Especially considering that somewhat milder air put up a bit of a fight up here this week.

Gaoth Laidir

About sea-effect showers, the main factors affecting the sea fetch required are both the temperature differential between the sea and 850 hPa and the 850-hPa windspeed and directional shear up to 700 hPa.

With the >13-degree difference a given, the optimum 850-hPa windspeed for organised bands is around 20 knots. Higher speeds require more of a sea fetch, but as there will be more like an 18-degree temperature difference and 850 hPa will be lower than the standard 1.5 km that required fetch will be reduced again. Directional shear between 850 and 700 hPa should be 30 degrees or less to keep some sort of organisation.

The GFS sounding for the middle of the Irish Sea shows no directional shear but around 30 knots easterly. Slightly high, but the large temperature difference should offset some of the limiting effect of that. It shows convection to around 700-650 hPa for a surface parcel warmer than that shown (allowing for warming nearer to Ireland), but the further north the lower the mid-level temperature and the deeper the convection.

At that particular point in time showers should be moving westwards and confined to the Irish Sea north of Anglesea, due to the easterly steering flow limiting fetch south of that. Dublin to Louth would be favoured in this scenario, with the stronger flow allowing showers to make it further inland. Here in north Kildare could be a good spot.

Tyrone212

Tyrone212 wrote: »

In my experience the models usually over cook snow totals from far out more often than they don't.

But the people you are replying to gave you examples, in a similar set up to this one where the opposite was true.

Edit.

And GL has a good post as well.

I was wondering if the sea might be a bit too cold compared to December 2010, this is probably when it is at its coldest.

nacho libre

The thing is Mogrep could be right, but that could mean much of England holds on to the cold while we go mild. There is scatter on the GFS suite but I think it is unlikely the op runs will upgrade to the extent that lows will trend far enough south in the next couple of days to prolong the cold for us.

Tyrone212

[Deleted User] wrote: »

But the people you are replying to gave you examples, in a similar set up to this one where the opposite was true.

Edit.

And GL has a good post as well.

I was wondering if the sea might be a bit too cold compared to December 2010, this is probably when it is at its coldest.

Well I believe I said more times than not they overcook totals from far out. I didn't say they always do. I didn't say there were zero examples of the opposite of happening. Not sure how it was so difficult to deduce that.

JCX BXC

Christ my eyes are bleeding from this thread. I'm sorry I read over the last 15 pages. Why do people reply to those who are clearly trolling and do so every event?

I was quite surprised to hear the blatant ramping by Evelyn on the radio today, it's very early to be discussing significant snowfall at the end of next week, it's 6/7/8 days away.

Can't imagine the West Coast will see much snow, charts done seem to think much and to be honest it's much too early to consider the frontal snow possibility, that will likely come down to fine tuning.

nacho libre

nacho libre wrote: »

The thing is Mogrep could be right, but that could mean much of England holds on to the cold while we go mild. There is scatter on the GFS suite but I think it is unlikely the op runs will upgrade to the extent that lows will trend far enough south in the next couple of days to prolong the cold for us.

Well if it doesn’t snow here the low has to bring mild air over southern England unless it directly comes in due West. Perhaps.

Some guy on NW said the difference in temps is 10 degrees between ensembles at his location. I reckon it’s to play for. Good model watching anyway.

Remember the gfs was expecting mild early next week just a few days ago.

Tyrone212

Tyrone212 wrote: »

Well I believe I said more times than not they overcook totals from far out. I didn't say they always do. I didn't say there were zero examples of the opposite of happening. Not sure how it was so difficult to deduce that.

You said more often than not. Which isn’t true of streamers and the most recent and memorable events which are similar to next week.

Tyrone212

[Deleted User] wrote: »

You said more often than not. Which isn’t true of streamers and the most recent and memorable events which are similar to next week.

More times than not, more often than not means the same thing. Well you're wrong. But sure they'll be 10 feet snow outside your house next week if that's what you want to hear.

The One Doctor

Tyrone212 wrote: »

More times than not, more often than not means the same thing. Well you're wrong. But sure they'll be 10 feet snow outside your house next week if that's what you want to hear.

You sound very like that other NI guy who complains all the time. Are you related?

Tyrone212

The One Doctor wrote: »

You sound very like that other NI guy who complains all the time. Are you related?

I'm not complaining. I posted the snow accumulations charts from the ecm and gfs for next week both of which are currently poor. Thats a fact. Complaining about said charts led to this discussion.

It can still improve but they usually overcook snow accumulations projections from far out. Some people are just to childish too accept what the charts are currently showing. It'll all end in tears if they turn out to be correct. I take it you're another one? Are you related to the other southern guy who's always complaining? You sound like him.

JCX BXC

Not even overcook, I find those snowfall charts are often very inaccurate. They may be of some use in a very close time period, anything last 2/3 days I wouldn't even bother looking. The smallest differences between runs completely changes what they show.

nacho libre

Deleted User wrote: »

Well if it doesn’t snow here the low has to bring mild air over southern England unless it directly comes in due West. Perhaps.



xt

To clarify, by much of England, I meant anywhere from the M4 northwards. I will be very pleasantly surprised if the GFS and ECM
switch to prolonging the cold spell here. I really want the chance of a significant snowfall to be on the table again!

sicknotexi

Tyrone212 wrote: »

I'm not complaining. I posted the snow accumulations charts from the ecm and gfs for next week both of which are currently poor. Thats a fact. Complaining about said charts led to this discussion.

It can still improve but they usually overcook snow accumulations projections from far out. Some people are just to childish too accept what the charts are currently showing. It'll all end in tears if they turn out to be correct. I take it you're another one? Are you related to the other southern guy who's always complaining? You sound like him.

That's one specific run. They're bound to change. Last nights GEM had us buried as did today's( though not as much). Even last nights ECM 00z had most of the island with decent totals.

KungPao

Weather app on my phone makes for sad reading. Had snow stretching from Sunday to Friday maybe 24 hrs ago. Reduced to Thursday only as of now. Temps not exactly Siberian either.

Humberto Salazar

Met E only talk about dusting of snow and and mostly dry away from eastern areas. I cannot see what we will get from this. Am I missing something? Yes, we are getting a three or four days easterly wind, cold, and a change from damp soggy weather. This is not Storm Emma or anything like that. I'm not trolling, just saying what the charts and forecasts show IMO.

Zogabomb

Humberto Salazar wrote: »

Met E only talk about dusting of snow and and mostly dry away from eastern areas. I cannot see what we will get from this. Am I missing something? Yes, we are getting a three or four days easterly wind, cold, and a change from damp soggy weather. This is not Storm Emma or anything like that. I'm not trolling, just saying what the charts and forecasts show IMO.

Was anybody expecting a Storm Emma scenario though? The general outlook for me hasn't changed. Met Eireann spoke yesterday about dustings of snow and then a few hours later mentioned significant snow, it seems their forecast changes based on whoever is on duty at the time. I'd expect some snow showers for Eastern counties on Monday, extending further on Tuesday with a few cms of snow for some, I'm pretty happy with that to be honest.

Cork2021

Humberto Salazar wrote: »

Met E only talk about dusting of snow and and mostly dry away from eastern areas. I cannot see what we will get from this. Am I missing something? Yes, we are getting a three or four days easterly wind, cold, and a change from damp soggy weather. This is not Storm Emma or anything like that. I'm not trolling, just saying what the charts and forecasts show IMO.

Change the record!!!
Why did Evelyn Cusack go on the radio yesterday and say they’re on high alert?
They know a lot more then you or I do!
It would be highly reckless of the head of forecasting to make a statement like that, she sees something the rest of can’t.

Humberto Salazar

Cork2021 wrote: »

Change the record!!!
Why did Evelyn Cusack go on the radio yesterday and say they’re on high alert?
They know a lot more then you or I do!
It would be highly reckless of the head of forecasting to make a statement like that, she sees something the rest of can’t.

Well, if she's in charge of the forecast this morning, it's mostly dry and very cold up to Tuesday. Wednesday debatable, Thursday we have an Atlantic low knocking on the door. Some wintry showers in the East, some getting through to the west. Nothing even rating a warning based on that. I get slammed for pointing out what other people write.

M.T. Cranium

This looks more like a "medium" snowfall outcome than the heavy events we had in 2018 or Dec 2010. I think some areas will do fairly well and get 5-15 cm coverings, others will be between bands and get 2-5 cm or even less. Some of the guidance is fairly generous with the inland extent of whatever snow streamers they detect, but as to their location being accurate at this time scale, probably better to take the output as a very general guide.

My impression of the "breakdown" potential is that most guidance is going for a fairly quick end to the cold spell, there would need to be a heavy snowfall band on the first warm front attacking otherwise it's going to be a missed opportunity on that part of the event.

Most likely day to see snow is probably Tuesday although Sunday to Thursday will be in the hunt so to speak.

torres9kop

Ah damn. And I promised the kids we’d be snowed in

bazlers

This must be the longest run in to an event in the history of events. Seems like its going on a month and we are still a few days off:pac::pac: