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

daheff

So folks... should I be going off to buy a snow shovel this weekend or what?

TTLF

daheff wrote: »

So folks... should I be going off to buy a snow shovel this weekend or what?

depends on your location :pac::D

lucernarian

highdef wrote: »

I think that is where the model changes from high to low resolution.

Actually what TTLF makes more sense!

It's possibly both come to think of it. I know other models can do this to optimise computer resources. Either way, I'd treat the ICON accumulation and precipitation charts both with a pinch of salt. Not for their peak potential for any one exact place, but how they show some contradictions in how they handle the general synoptics and that it's a global model and not a mesoscale model.

I more dread the salt on Wednesday in this thread if snow trains don't reach Dublin by the smallest margins than aiming lower on the projections there. That point bears out for quite a few other places, I'm sure a certain regular here in Arklow is probably cursing what some of the charts are showing :<

pistolpetes11

Rebelbrowser wrote: »

Is there a VAR to double check your decisions?

Danno is in Glasnevin 😂😂😂

munsterlegend

Rebelbrowser wrote: »

Is there a VAR to double check your decisions?

Straight red for questioning the ref. This is rugby rules.

TheMilkyPirate

TheMilkyPirate wrote: »

Anyone any idea why ICON changes like this within one frame? Been doing it last few days

3 hours later heavier precip?

Holy Duck

Might be no harm for the Lovey Dovvies to have their chocolates and teddy bears on standby, wouldn't want to be slip sliding away on the big day....(14th)

TTLF

I should probably go get my homework done so I can actually enjoy the snow possibilities next week :eek: been distracted with the weather...

I feel like sryanbruen when he was too distracted to do his homework during the BFTE charts before the event

hope to be back later.

tbayers

Regarding Waterford area (and maybe more specifically Tramore) would wind need to be ESE or would E and/or ENE winds let streamers make it to Waterford?? Or would they have to cross Wexford coast and over the River Suir and perhaps reload?

Humberto Salazar

daheff wrote: »

So folks... should I be going off to buy a snow shovel this weekend or what?

If you live in Moscow, sure. Here, not so much.

Tyrone212

Calibos wrote: »

Its constantly said that the models under estimate streamers.

I assume this means that they are not programmed to take into account every single little variable that can affect their formation and then their intensity.

However, one has to assume that no matter how many variables and conditions are met, THE most important one with the strongest effect is Sea Fetch. So it doesn't matter if every other condition is met, if you don't have the Sea Fetch, none of it really matters.

This is why knowing what direction the wind is blowing at the required level (700-850mb) is so important in order to work out if you have any chance at all of anything decent.

Now even if the precipitation models are not programmed to take into account all the variables (Which is why we can't 100% trust them) surely the one variable guaranteed to be programmed into them right is the Wind direction at the relevant height.

ERGO, if the precipitation models are showing high intensity into Meath and Louth from due East, surely we can at least trust that it got the wind direction at 700-850mb right. What we can't trust is the intensity. Might be overblown, might be under-cooked, the most intense region of precipitation might be a bit further south etc, but broadly speaking the model will have got the general area right.

If the only thing you can trust about the precipitation model is the track/direction of the Streamers than surely experience tells us that most of Dublin and Wicklow will be in the Angelsey/Wales shadow and end up getting SFA.

The overall point I am making is that when some of us see the latest output and have a little moan that it doesn't look like we'll get much if anything, we are told to relax and that the Precipitation models can't be trusted anyway. My point is that surely at the very least the orientation/direction of the Streamers on the Precipitation models can be trusted, in which case we can make educated guesses based on experience which of the various Irish Sea Precipitation Shadows are going to affect us.

Very well explained. Cheers.

lucernarian

Humberto Salazar wrote: »

If you live in Louth, sure. Here, not so much.

FTFY

CirrusBusiness

daheff wrote: »

So folks... should I be going off to buy a snow shovel this weekend or what?

No harm in having one just in case. I bought a mini sized as it's easier to manoeuver, plus some large bags of rock salt last week. Have a feeling this cold could deliver the goods possibly on Thurs and after that we may even get a deeper cold with more snow than this week. Emphasis on *could and *may.. it's hard to predict how much snow anywhere will get until much closer to the time but certain areas in line with streamer trains will get a nice covering even before Thurs.

Rebelbrowser

tbayers wrote: »

Regarding Waterford area (and maybe more specifically Tramore) would wind need to be ESE or would E and/or ENE winds let streamers make it to Waterford?? Or would they have to cross Wexford coast and over the River Suir and perhaps reload?

You could get them either way depending on wind direction and wind strength. The direct sea route best option though

daheff

TTLF wrote: »

depends on your location :pac::D

West dublin/north Kildare

TTLF

daheff wrote: »

West Dublin/north Kildare

will depend on Wind direction at times, but I wouldn't rule out any possibilities of a decent covering Monday night or even Tuesday, no BFTE though imo

Zogabomb

Nice forecast on RTE TV just there, snow showers starting tomorrow night in The East, continuing Monday and more widespread Tuesday and Wednesday with the chance of more significant snow for much of the country on Thursday.

I wonder are their hi-res models seeing more potential than we see?

munsterlegend

Zogabomb wrote: »

Nice forecast on RTE TV just there, snow showers starting tomorrow night in The East, continuing Monday and more widespread Tuesday and Wednesday with the chance of more significant snow for much of the country on Thursday.

Carlsberg don’t do weather forecasts but if they did that front on Thursday would stall over the country.

Slashermcguirk

I expect met Éireann will be out with some warnings from tomorrow morning. Good to hear the RTE broadcasts now bringing more certainty on the snow from tomorrow night onwards

Zogabomb wrote: »

Nice forecast on RTE TV just there, snow showers starting tomorrow night in The East, continuing Monday and more widespread Tuesday and Wednesday with the chance of more significant snow for much of the country on Thursday.

I wonder are their hi-res models seeing more potential than we see?

Shadylou

How likely is cork city to get snow? Don't have my hopes up but the kids are all hyped up

Nqp15hhu

TheMilkyPirate wrote: »

Anyone any idea why ICON changes like this within one frame? Been doing it last few days

81 hours is using 'low resolution' so the chart has less confidence in that time period but also the pixels don't cover the same amount of detail.

munsterlegend

Shadylou wrote: »

How likely is cork city to get snow? Don't have my hopes up but the kids are all hyped up

A good chance I would think. As to how much is very much a nowcast.

Davaeo09

Nqp15hhu wrote: »

81 hours is using 'low resolution' so the chart has less confidence in that time period but also the pixels don't cover the same amount of detail.

That seems to show a southern band of streamers for Wexford and inland south east right? :eek::D:)

JanuarySnowstor

Gaoth Laidir wrote: »

The devil's always in the detail!

I think 850 temperatures were several degrees colder then than this week and we didn't have this sloppy Joe Low directly before it. My main point is about boundary layer-modification with such a long fetch with slightly warmer upper temperatures. Time will tell.

You do make a good point about that nearby low going under on Tuesday. It may interfere and cut off any convection for the South...yes it could also be sleety by the coast with uppers a tad higher than 2018. Saying that 2018 it snowed on the beach and it was almost March so I do think we are right side of marginal even at the coast. What's more important for places like Cork City is its very hilly and hilly areas should see snow. I think we could see a lot of soft hail / graupel in this type of setup

Nqp15hhu

JanuarySnowstor wrote: »

You do make a good point about that nearby low going under on Tuesday. It may interfere and cut off any convection for the South...yes it could also be sleety by the coast with uppers a tad higher than 2018. Saying that 2018 it snowed on the beach and it was almost March so I do think we are right side of marginal even at the coast. What's more important for places like Cork City is its very hilly and hilly areas should see snow. I think we could see a lot of soft hail / graupel in this type of setup

If the humidity is low with a subzero wet bulb temperature it can snow out to sea. The air temperature only has to be moderately low for snow in these conditions.

Chong

Latest harmonie from Met.ie reporting rain now till Monday


https://twitter.com/meteireann/status/1358035671051608067?s=21

HansKroenke

No use of the words "snow" or "accumulations" in any of the Met Éireann forecasts. It's important to note that.

Edit: apart from Sunday night where a light dusting of snow is mentioned.

Chong

HansKroenke wrote: »

No use of the words "snow" or "accumulations" in any of the Met Éireann forecasts. It's important to note that.

I want snow it’s a welcome distraction but the likes of the Met seem like they are on another planet.

Davaeo09

Davaeo09 wrote: »

That seems to show a southern band of streamers for Wexford and inland south east right? :eek::D:)

Yes
Its a maybe
My hunch is they'll be there but wind speed might scupper this lessening the ability to Scoop up/Fetch all that water

Gaoth Laidir

Latest wet-bulb temperatures. A lot of slop to get rid of before the colder air over the North Sea can make inroads. Need that low over the UK to gtfo.

12Z soundings of 925 hPa (~650-700 m) 850 and 700 hPa temperatures.