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

King of Spades

Gaoth Laidir wrote: »

Just to note too that in a northeasterly, frictional convergence along the south Down coast (winds slower over land and hence more northerly) would enhance convection there, leading to higher precipitation totals in say Louth - Meath. You can see that in the last frames of Kermit's animation above.

That's one of the local effects that can tip the balance one way or the other.

That’s really interesting and something I’d never known. You’re a mine of useful information as are a lot of other posters on this forum. Thanks a million all for sharing the knowledge and updates. Hope everyone gets a fair share of snow (if that’s your preference) next week. Exciting times.

Nqp15hhu

Gaoth Laidir wrote: »

Just to note too that in a northeasterly, frictional convergence along the south Down coast (winds slower over land and hence more northerly) would enhance convection there, leading to higher precipitation totals in say Louth - Meath. You can see that in the last frames of Kermit's animation above.

That's one of the local effects that can tip the balance one way or the other.

Do you sit down and study meteorological topics everyday? We didn’t cover half of these topics in my degree.

Steopo

I find Met.ie meteorologists commentary from yesterday a pretty useful current summary of the week ahead. I don't find there's any great mystery about their forecasts. They use the ECM model largely as the basis for their midrange forecasts together with a lot of meteorology experience and I'm sure they use a higher resolution model than charts available for free as ECM charge anywhere from 5k to over 100k for those higher resolution/archive models. Obviously other models show differing outcomes to ECM and everyone can have interpretations and opinions on those but I think Met.ie are very open about what they base their mid range forecasts on and I think this one is a pretty good summary on where we're at.

"Snowfall is expected in the form of showers from Sunday onwards, but more especially later on Monday and during Tuesday. Any showers are likely to be restricted to eastern parts of Leinster and Ulster initially, but a few may push further inland during Tuesday.

There is still a high degree of uncertainty in the forecast from Wednesday 10th February onwards, but it looks as though Atlantic frontal systems will attempt to push milder air in from the south to displace the cold air in situ over Ireland.

It is still too early to predict how energetic or vigorous these frontal systems will be, and that has a downstream effect on the impact that this clash of mild and cold air may have over Ireland. If the frontal feature is vigorous, for example, it would likely make quick progress northeastwards over the country and any associated snowfall would be a transient affair with rain following behind. However, if the frontal system has less energy as it comes towards us and starts to become slow-moving either on its approach or as it tracks over us, we could end up in a situation where some parts of Ireland could see more significant and lasting snowfall."

https://www.met.ie/forecasts/meteorologists-commentary

Chalkitdown147

Nqp15hhu wrote: »

Do you sit down and study meteorological topics everyday? We didn’t cover half of these topics in my degree.

Fascinating isn't it?? I presume locality has a huge influence on your forecasting/model watching because it's particular unique what he describes above

Donegal Ken

Northern parts the Inishowen peninsula, Donegal could do very well out of these streamers also. Possibly even around Downings and Dunfanaghy them general areas with a large train effect. All the talk about the east but i think sometimes these areas are forgot about. Back in 2018 they got significant accumulations also with the rest of Donegal receiving barely a trace.

Cluedo Monopoly

Bio Mech wrote: »

Is there a list of banned words for this thread? If so I propose we add “Shadow”.

Also Anglesey, Mann and snow shield.

Ridemesideways was another one.

I don't know much about models and stuff but I love dipping into these threads to watch the confidence rollercoaster.
I tend to dwell longer when the models are ramping

At this point I just want some really cold weather. I love hiking on frosty ground.

pauldry

Dont think Sligo (apart from Ben Bulben) will see much from this but at least it will be dry. Tuesday into Wednesday might be our best hope but no doubt if snow comes to Sligo it will be after the rest of ye get buried and on the transition period to rain

AndyBoBandy

Whats the general consensus on thread of what we'll get next week?

Have an essential trip from Dublin to Cork & back next Thursday, and could do without snow covered motorways, or Cork!!

alchemist33

Donegal Ken wrote: »

Northern parts the Inishowen peninsula, Donegal could do very well out of these streamers also. Possibly even around Downings and Dunfanaghy them general areas with a large train effect. All the talk about the east but i think sometimes these areas are forgot about. Back in 2018 they got significant accumulations also with the rest of Donegal receiving barely a trace.

Boy do I remember that. Dublin snowed in and not a flake around Letterkenny. I even had to go into work.

Humberto Salazar

Advisory issued by Met.ie but nothing exceptional expected other than take care, wrap up. There isn't any major snow event expected, up to Wednesday next.

Oneiric 3

Another area to maybe keep an eye on is along the very north coast during this upcoming spell. Models have been showing 'streamers' (i.e, showers) also running along this area also over the course of early next week for a few runs now. Malin Hd could be a station to keep a glancing eye on:

pistolpetes11

Humberto Salazar wrote: »

Advisory issued by Met.ie but nothing exceptional expected other than take care, wrap up. There isn't any major snow event expected, up to Wednesday next.

Generally they wouldn't be advising this far out ...........

Akrasia

Davaeo09 wrote: »

All the talk about shadows and distance needed for proper "lake effect" snow, has had me drawing lines on google maps like I actually know what I am doing

I always used to get frustrated watching streamers go North of me, then the next day to the South.
How variable can the wind direction actually be over the space of 12-24 hours???
Many questions, much confusion.

Don’t draw your lines straight follow the arc of the closest lines of latitude if there are any

Patches oHoulihan

Humberto Salazar wrote: »

Advisory issued by Met.ie but nothing exceptional expected other than take care, wrap up. There isn't any major snow event expected, up to Wednesday next.

So no new Beast from the East?

Humberto Salazar

pistolpetes11 wrote: »

Generally they wouldn't be advising this far out ...........

They did before the last snap I think. And they were spot on in fairness with how it transpired.

pistolpetes11

Humberto Salazar wrote: »

They did before the last snap I think. And they were spot on in fairness with how it transpired.

Output is changing every model run , they are damed if they do and damed if they don't , Ive always found them to take a more cautious run at these types of events myself and rightly so IMO

sryanbruen

The advisory for the Beast from the East was issued at midday on Friday 23 February 2018. The day the streamers really took off was later on the 27th into the 28th.

Been reading through the old discussions, funny how little focus there was on streamers or potential of them and Storm Emma was in the spotlight. Everybody loves to look for a breakdown it seems.

Still echo my thoughts as per post yesterday. Tuesday and Wednesday the days to look out for possibilities of streamers but this is far from a classic event and it was never looking like so either.

Dazler97

Weather advisory issued for Eastern counties from Sunday till Wednesday for sleet and snow showers, we've hardly any warnings Compared to the UK

pistolpetes11

sryanbruen wrote: »

The advisory for the Beast from the East was issued at midday on Friday 23 February 2018. The day the streamers really took off was later on the 27th into the 28th.

Been reading through the old discussions, funny how little focus there was on streamers or potential of them and Storm Emma was in the spotlight. Everybody loves to look for a breakdown it seems.

Still echo my thoughts as per post yesterday. Tuesday and Wednesday the days to look out for possibilities of streamers but this is far from a classic event and it was never looking like so either.

The voice of reason !

Well done

ninebeanrows

Not liking the slight adjustment to the air-flow on the 12zs , more of a SSE or direct E on some of the runs. Let's hope the direction will change on later runs from a IMBY perspective.

brianthomas

Chalkitdown147 wrote: »

I think that it's ENE from true north so North Kildare/West Dublin should be in firing line regardless of the small wind changes......but I maybe open to correction by the wise weather folks in here

Clondalkin here and there were conditions I think it was 2010 where the IOM shadow was causing us some issues on the incoming streamers, literally see the clouds to the north and south of me and a hole in the sky above me and from memory, that was during North East winds but like that, it flipped and flopped and we got destroyed with snow in the end but always something to keep an eye on during these easterly setups for Dublin in general.

Dazler97

brianthomas wrote: »

Clondalkin here and there were conditions I think it was 2010 where the IOM shadow was causing us some issues on the incoming streamers, literally see the clouds to the north and south of me and a hole in the sky above me and from memory, that was during North East winds but like that, it flipped and flopped and we got destroyed with snow in the end but always something to keep an eye on during these easterly setups for Dublin in general.

I used to live in firhouse, just down from tallaght and yes it would depend on the IOM shadow and streamers etc, also we can also get the Welsh shadow as well but it's less common

Winterstale

This feels like the most protracted run up to a cold spell I can remember. Im beginning to think it's not worth the ups and downs from run to run. Now according to the UKMO the wind has shifted to a SE flow for Tuesday which puts the mockers on much of the east coast promised streamers. Great for the south coast and further North perhaps. I hope someone gets to enjoy some snow. As an easterner I've a pain in my hoop with it now. Give me Sunday 23rd of January over this potential flop any day. Less promised, more delivered.

DOCARCH

Winterstale wrote: »

This feels like the most protracted run up to a cold spell I can remember.

There has been far far worse....with it all fizzling away 24 hours out!

Not getting excited until I see charts on Sunday!!!

Squidvicious

ninebeanrows wrote: »

Not liking the slight adjustment to the air-flow on the 12zs , more of a SSE or direct E on some of the runs. Let's hope the direction will change on later runs from a IMBY perspective.

Hopefully, but I wouldn't be too worried about it at this stage. I would prefer an NE flow myself but nothing's nailed down yet. I've been looking at the wind direction predictions on windy.com and while Monday and Tuesday are ENE, by Tuesday evening it's backing NE and that will probably change between now and then too.

DOCARCH

Calibos wrote: »

My sentiments exactly.

Its all gone tits up in todays models for the East Coast and I’ve made a fool of myself getting excited yet again. i thought Mon-Wed was already locked in for something decent and it was just Wednesday onwards that the models were having trouble with.

If it did end up a SE flow, might not be the absolute end of the world (for you at least). With the right conditions, and a SE flow, in the past I have seen streamers develop in Cardigan Bay and hit south Dublin/north Wicklow.

DOCARCH

Oneiric 3 wrote: »

You are needlessly panicking. Guaranteed you'll see some snow at times from this set up. How much is still up for grabs.

Yip. Get the cold here first then worry about the snow!

Kermit.de.frog

DOCARCH wrote: »

Yip. Get the cold here first then worry about the snow!

There'll be no issue with the cold, that's for sure!

ninebeanrows

Spring blossoms next weekend :P

ninebeanrows

ninebeanrows wrote: »

Spring blossoms next weekend :P

Its reminding me of February 1991 in Arklow, though that went on for about 8 days
We had just flurries in Arklow until the Friday morning when with a slight shift to NE,the heavens opened with sand storms of snow roughly wicklow to Gorey,dropping around 15cms
Following Tuesday Summer arrived and the giant thaw