Prolonged cold spell on the way

Trogdor

Looks like wetterzentralde.de is struggling with all the traffic viewing the 12z gfs i'd say..

MUSEIST wrote: »

Anyone else notice how the -5 uppers are being pushed back on every run (until eventually they never arive)

That nearly always seems to be the way when a cold spell is forecast..if you have faith they'll eventually arrive though;) The second half of next week certainly is looking very good at the moment, lets hope it stays that way!

maquiladora

Oh man 12Z GFS is starting to look good...very good...here come the -10 850's

Figuramatyi

MUSEIST wrote: »

Anyone else notice how the -5 uppers are being pushed back on every run (until eventually they never arive)

From what I can see, it's being pushed back further SW with every run:


Now this is just outrageous.

Trogdor

Yummy stuff on the 12z!

arctictree

A bit FI but mad. -10 uppers? Some places could have a frost day.

maquiladora

A shame that its in FI and will probably downgrade.

-10 850s covering the country :



Bitter :



Precip :



:cool:

BEASTERLY

The GFS 122z puts the breakdown back another 36-48hrs:D

The GFS is looking scarrily similar to the charts for mid-december 2009 onwords!

Kippure

Epic 12z run :eek:

jambofc

this time next week.....

the temperature inland stays below freezing all day and the east coast has light snow showers all day,settling due to the severe cold,the country comes to a stand still as the government sold all the salt for cheese

maquiladora

Kippure wrote: »

Epic 12z run :eek:

FI is insane. At 189 hours (9am Sunday morning) there are maximum surface temps of -7 in places.

Meanwhile here is a closer look at the 850 temps around 160 hours :



:rolleyes:

I don't think this will happen. Its November.

Kippure

maquiladora wrote: »

FI is insane. At 189 hours (9am Sunday morning) there are maximum surface temps of -7 in places.

Meanwhile here is a closer look at the 850 temps around 160 hours :



:rolleyes:

I don't think this will happen. Its November.

It wouldnt be to surprizing if it did happen. Based on the similar patterns we are seeing to last year.

thetonynator

Kippure wrote: »

It wouldnt be to surprizing if it did happen. Based on the similar patterns we are seeing to last year.

But its now much earlier in the year than last years cold spell.

Su Campu

If it does happen like the GFS says (which it most certainly won't) it will be too early IMO. Yeah we get a fairly cold period November-early December, but the pattern would most certainly have shifted come our window for real cold - January - and it could be an awfully long month if it turned out be Atlantic-zonal, and this cold period would long since be forgotten.

So let this taxi pass - there'll be plenty more coming behind.

darkman2

In response to Su Campu earlier - im 100% confident I have this right;)


Anyway UKMO.....things are looking exceptionally poised right now




BNasically in a nutshell turning progressively colder with really very severe frosts next week inland, icy patches and wintry showers increasingly of snow to all levels later in the week.

ninebeanrows

Su Campu wrote: »

If it does happen like the GFS says (which it most certainly won't) it will be too early IMO. Yeah we get a fairly cold period November-early December, but the pattern would most certainly have shifted come our window for real cold - January - and it could be an awfully long month if it turned out be Atlantic-zonal, and this cold period would long since be forgotten.

So let this taxi pass - there'll be plenty more coming behind.

What!?

These synoptics are fantastic and would deliver snow, yes the SSTs in the Irish sea are a little high but if we get our -10c 850hpas that will just mean juicier snow showers

Su Campu

darkman2 wrote: »

In response to Su Campu earlier - im 100% confident I have this right;)

How can you be 100% confident? You're reading models, which are never 100% right, especially 5-6 days away.

Maybe it was a tongue-in-cheek comment, which if it was, then grand

Su Campu

Weathercheck wrote: »

What!?

These synoptics are fantastic and would deliver snow, yes the SSTs in the Irish sea are a little high but if we get our -10c 850hpas that will just mean juicier snow showers

Musicman2000

I think I have to agree with SU on this one, It could all change again in the next few runs

arctictree

All eyes on the ECM 12z! Will it, wont it....

maquiladora

Time for a reality check lads.

http://91.121.84.31/modeles/gens/graphe_ens3.php?x=109&ext=1&y=2&run=12&runpara=0

The operational run was several degrees colder than the mean between 25th and 29th.

I expect we will see an adjustment to more realistic stuff on the 18Z.

Enjoy the 12Z while it lasts. :pac:

BEASTERLY

I have a bad gut feeling that were now at the top of the rollercoaster, and it may be a long way down to reality!

EDIT: OH NO! ECM at 120hrs high sinking south, disaster!:rolleyes::(

maquiladora

BEASTERLY wrote: »

I have a bad gut feeling that were now at the top of the rollercoaster, and it may be a long way down to reality!

Very possible. But it wouldn't be much of a rollercoaster if you didn't enjoy the ups and downs of the ride.

thetonynator

I think su may be right on this one . . .it wont be the big freeze we're anticipating . ..

Weathercheck

Weathercheck wrote: »

What!?

These synoptics are fantastic and would deliver snow, yes the SSTs in the Irish sea are a little high but if we get our -10c 850hpas that will just mean juicier snow showers

I think you'll need every bit of your below -8 850's and definitely -10 850's initially anyway to stop that snow turning to rain/sleet at times in the warmer air the precip passes through in last 1000ft to the ground over the irish sea and in coastal areas..
Helping matters will be that the showers could potentially be massive ones with air that cold passing over what is currently a relatively very warm sea.

This is what I kind of like about the trend here.I'm thinking folks not to get the hopes up in the initial few days of this-I mean not to get the hopes up about next weekend.
Theres too many things that can go slightly wrong .. as to be fair to Su Campu..you do want everything on board for the last week in november for non localised interesting weather to occur.
If the trend is for sustained Easterlies/Northeasterlies,then we will increasingly be pulling in a colder surface layer to wipe out the effect of the warm seas on that first 1000ft or so above them.
We'll also be pulling in better dewpoints onto the sea and coast.

Patience pedwans..Patience.

maquiladora

12Z ECM doesnt break down the cold in FI but it's a very different run than GFS/UKMO.

Nothing nailed at the moment apart from the fact it will start to get colder early next week.

JanuarySnowstor

maquiladora wrote: »

12Z ECM doesnt break down the cold in FI but it's a very different run than GFS/UKMO.

Nothing nailed at the moment apart from the fact it will start to get colder early next week.

Please guys C'mon what lies ahead is a bit better than 'start to get colder'
I back weathercheck on this, looks plenty cold enough for snow.
Dew points SU ??????

maquiladora

thetonynator wrote: »

I think su may be right on this one . . .it wont be the big freeze we're anticipating . ..

I guess it depends on what you'd classify as a big freeze but Met Eireann says "at night temperatures will plummet well below freezing across many parts".

darkman2

Once were below -5 snow is likely, initially not on coasts, but I disagree with BB. It should be snowing on coasts by the end of next week if things hold together. I have no doubt whatsoever about that. Everything is in place at that stage.



Two points about tonights ECM - firstly we would take it anyway this time of year, it's still very cold with frost, ice and snow potential.

Secondly every other model supports the GFS in the evolution to 144hrs. Even the UKMO supports it. So I would not be too flustered.

maquiladora

JanuarySnowstor wrote: »

Please guys C'mon what lies ahead is a bit better than 'start to get colder'

All we know for sure at this stage is it will start to get colder. How cold, for how long & if it will be a dry or maybe snowy spell are still all in the realm of FI.

I think the models look very good for this time of year. Its exciting to see stuff cropping up in these runs in Nov that you wouldn't expect to see until Dec or Jan. Very entertaining for weather fans. But we have to remember that things can and do fall apart & downgrade.

darkman2

All at 120hrs on the main models which is next Thursday

UKMO





GFS





GEM




JMA




GME





NOGAPS




ECM

Su Campu

JanuarySnowstor wrote: »

Please guys C'mon what lies ahead is a bit better than 'start to get colder'
I back weathercheck on this, looks plenty cold enough for snow.
Dew points SU ??????

Yes, plenty cold enough for snow at high levels, as I said this morning, but for the vast majority of the popluation that lives below a couple of hundred metres, there should be nothing more than sleet I'd say.

It's looking like any precipitation this week will be in the form of lake-effect showers, which will affect coastal areas of the northeast, east, and north Mayo. These will quickly die out as they move inland due to lack of instability. Remember we'll be under the influence of a large high to our northwest, so that will be trying to warm upper levels, and put cap on convection. The models hint that a low will push in from our east, which would enhance activity, but I think the stinker will be the sea surface temperatures. I don't trust the GFS dewpoints, which are being forecast down to almost minus double figures, and 850 Theta-W down to 1 or 2°C. That would give snow, yes, were it to happen - I just don't think it will.

I certainly think we'll see white tops on the mountains, but there'll be no snow lying at low levels.

ninebeanrows

Su Campu wrote: »

Yes, plenty cold enough for snow at high levels, as I said this morning, but for the vast majority of the popluation that lives below a couple of hundred metres, there should be nothing more than sleet I'd say.

It's looking like any precipitation this week will be in the form of lake-effect showers, which will affect coastal areas of the northeast, east, and north Mayo. These will quickly die out as they move inland due to lack of instability. Remember we'll be under the influence of a large high to our northwest, so that will be trying to warm upper levels, and put cap on convection. The models hint that a low will push in from our east, which would enhance activity, but I think the stinker will be the sea surface temperatures. I don't trust the GFS dewpoints, which are being forecast down to almost minus double figures, and 850 Theta-W down to 1 or 2°C. That would give snow, yes, were it to happen - I just don't think it will.

I certainly think we'll see white tops on the mountains, but there'll be no snow lying at low levels.

Very strong statement.

I disagree, think snow should fall to low levels from Friday and into the weekend.

This is of course if the current charts are correct.

And not the ECM, ECM delays the cold but offers good long term potential. An Outlier i would suggest, over-egging the shortwave over N Norway.

darkman2

Su Campu wrote: »

but I think the stinker will be the sea surface temperatures..

They will drop very quickly though with the airmass off the continent - first over the North sea, then the Irish sea. Once the SST goes below 5C in the Irish sea and land temperatures during the day are hovering close to freezing then there won't be enough modification to prevent coastal snow. Does not matter what time of year it is this is an exceptionally cold airmass coming.

maquiladora

Su Campu wrote: »

I certainly think we'll see white tops on the mountains, but there'll be no snow lying at low levels.

A brave call Su! Just to get it in the right context, does your feeling that there will be no snow lying at low levels extend for however long the cold spell lasts or up to some particular point in time such as next Sunday for example?

Looks like we have a good old weather debate about this upcoming spell here now.

I think it's too early to call one way or the other yet myself.

maquiladora

darkman2 wrote: »

They will drop very quickly though with the airmass off the continent - first over the North sea, then the Irish sea. Once the SST goes below 5C in the Irish sea and land temperatures during the day are hovering close to freezing then there won't be enough modification to prevent coastal snow. Does not matter what time of year it is this is an exceptionally cold airmass coming.

What are the SSTs for the Irish Sea at the moment, around 12 or 13? Can they really drop to below 5 that quickly?

darkman2

maquiladora wrote: »

What are the SSTs for the Irish Sea at the moment, around 12 or 13? Can they really drop to below 5 that quickly?

Yes. It takes longer then land temperatures (and even longer if there is a strong wind) but depending on the depth of cold and the source they can drop quickly enough and not too far behind the land temps - a continental flow which has a cold source is the best option for this rather then a sea based one.


GFS is a case is point when you have the right conditions progged.

BEASTERLY

maquiladora wrote: »

What are the SSTs for the Irish Sea at the moment, around 12 or 13? Can they really drop to below 5 that quickly?

Yep, bouy m2 is recording a sea temp if 13 degrees atm. I think they were around 6 during last years cold spell.

Well, snow settled without any problems at low levels here in wexford in late november 2005, so whats different this year were the synoptics are alot better?

Su Campu

darkman2 wrote: »

They will drop very quickly though with the airmass off the continent - first over the North sea, then the Irish sea. Once the SST goes below 5C in the Irish sea and land temperatures during the day are hovering close to freezing then there won't be enough modification to prevent coastal snow. Does not matter what time of year it is this is an exceptionally cold airmass coming.

Exactly what sort of drop are you expecting in the space of a few days? The Irish Sea's 11-12°C now, you're expecting it to cool by around 1 degree per day? That will not happen darkman, the sea is water, not acetone.



Maq, I've been talking about up to the end of this week. Obviously the longer it continues the easier snow becomes, but it will take a long spell for the seas to cool enough for the January-like conditions that people are throwing around.....

maquiladora

BEASTERLY wrote: »

Well, snow settled without any problems at low levels here in wexford in late november 2005, so whats different this year were the synoptics are alot better?

25th Nov 2005?

This is the archive chart for that day. -8 upper temps extending down over much of the country for a few hours in a northerly flow :



And this is the Met Eireann warning for that period :

Issued at 23 November 2005 - 13:00Severe Weather Warning for Snow

Frequent snow showers are likely to give accumulations of between 3 and 8 cm below 250 metres during the period 1200 hours Thursday to 2400 hours Friday in counties Donegal, Mayo, Sligo, Leitrim and parts of Cavan. Strong to gale force Northerly winds will occur during the same period, giving blizzard conditions at times and causing some drifting.

Su Campu

BEASTERLY wrote: »

Yep, bouy m2 is recording a sea temp if 13 degrees atm. I think they were around 6 during last years cold spell.

Well, snow settled without any problems at low levels here in wexford in late november 2005, so whats different this year were the synoptics are alot better?

How low is low?

ninebeanrows

I think the M2 buoy will be looked at with great interest at the end of next week.

What we look for from the M2 buoy is a DP below 0c, preferably around -1/2c with a temp of no more than 4/5c.

BEASTERLY

Su Campu wrote: »

How low is low?

There was a picture on the front of the independant i think of decent snow cover in kilmuckridge, it's at about 45m asl and around 2.5km from the coast. So a proper low lying coastal location.

But i didn't realise the synoptics were as good as they actually were, thanks for the chart maq and SSTs could well have been lower.

darkman2

Su Campu wrote: »

Exactly what sort of drop are you expecting in the space of a few days? The Irish Sea's 11-12°C now, you're expecting it to cool by around 1 degree per day? That will not happen.

Wanna bet? I will happily go for a 6 or 7C drop in SST's in the Irish Sea based on current projections. Obviously if something radically changes synoptically then it does not apply.

ninebeanrows

darkman2 wrote: »

Wanna bet?

Darkman, don't confuse the SST with the air temperature at the Buoy.

There is no way the SST will fall from 11c to 5c in 10 days.

The Buoy Temp could definitely fall from 11c to 5c though.

Su Campu

darkman2 wrote: »

Wanna bet?

You're on. The Irish Sea will not cool by a whole 6°C by next Friday! I say 1, maybe 1.5 at most.

darkman2

Im gonna stick that in my sig....you can put my prediction in your sig.

Su Campu

darkman2 wrote: »

Wanna bet? I will happily go for a 6 or 7C drop in SST's in the Irish Sea based on current projections. Obviously if something radically changes synoptically then it does not apply.

You are referring to water temperatures, aren't you?? You are trying to defy the laws of the Universe of you say the temperature of the water will fall by 6 or 7°C in less than a week!!! It won't happen, so pay up now!!

Of course I see the little disclaimer you put in at the end there. I though you said you were 100% confident???

gally74

all in all im delighted, i love cold "continenatal" type weather, fresh in the morning and dries everything up, not too concerned if we get snow or not, but nice n dry with frost is jsut lovely,

mayve with the imf the weather will be more "continental" like,

darkman2

Su Campu wrote: »

You are Referring to water temperatures, arent you? You Are Trying to defy The Laws of the Universe of You Say the temperature of the Water Will Fall by 6 or 7 ° C in Less than a week! It Will not Happen, so pay up now! : D

Of course I see the little disclaimer you put in at The End There. I though You Said You Were 100% confidant ???[/ QUOTE]

I am.


If the M2 buoy shows a 6C + drop I win.: Pac:

Su Campu

darkman2 wrote: »

Su Campu wrote: »

You are Referring to water temperatures, arent you? You Are Trying to defy The Laws of the Universe of You Say the temperature of the Water Will Fall by 6 or 7 ° C in Less than a week! It Will not Happen, so pay up now! : D

Of course I see the little disclaimer you put in at The End There. I though You Said You Were 100% confidant ???[/ QUOTE]

I am.


If the M2 buoy shows a 6C + drop I win.: Pac:

So you say the M2 will register a sea water temperature of at most 6.9°C by next Friday (it currently at 12.9°C)? You're barking mad!

For your info, the specific heat capacity of water is 4180J/kg/K......you want one last chance to redo your calculations??!!!!