Cold Spell Prospects and Discussion (January + Early Feb 2012)

Nabber

We have to play the waiting game. Wait till at least +72hrs. The models aren't reliable enough past 72hrs, with the way things are balanced any minor change could make a massive difference. We could end up with a South Easterly, North Westerly or an East to South Easterly......

We are smack bang in the middle here.
Still think the Azores high is going to finish this winter the way it started it. Dominating our weather.

TheMilkyPirate

18z is a cracker, shame it's not the 12z!

Musicman2000

Looks like the good old GFS pub run is going to be good.....:D

premiercad

Nabber wrote: »

We have to play the waiting game. Wait till at least +72hrs. The models aren't reliable enough past 72hrs, with the way things are balanced any minor change could make a massive difference. We could end up with a South Easterly, North Westerly or an East to South Easterly......

We are smack bang in the middle here.
Still think the Azores high is going to finish this winter the way it started it. Dominating our weather.

This gfs run is better Russian high nudges closer and closer, I think the significant thing on his run if its to be believed is some quite strong lows getting deflected back up towards Iceland, leaving the door open for cold weather, still god only knows how the 0z will fair

TheMilkyPirate

While the winter of 2010 was the year of graupel, This is most certainly the winter of the shortwave!

Sponge Bob

Far as I am concerned the important thing in the near term is the cold 2M temps moving west FOLLOWED by the Siberian High coming in across this frozen terrain.

Lets do 24 48 72 and 96 hours then shall we. Colder??
?
24



48



72



96

pistolpetes11

Any one for snow

pistolpetes11

The raging Jet Stream hit our Massive Scandi/Siberian Block and stops it dead in its tracks

Redsunset

OK then, What we got so far. Well I think we can all agree that there will be strong push of very cold air from the heart of Siberia trying to make that long trek across the continent to our little Isle. It is great to watch its progress on the models as it is indeed a super cold air feed, however I keep seeing deflection after deflection as it gets near us. I do really wonder if it will make it all the way. Still early days at the moment and very promising but by no means a certainty.

Emotions I feel are going to be running high in here for the foreseeable future and understandably so. However lets not get the forum into a mental breakdown if the Beast from the east gets the door slammed shut.

This is our best chance of the entire winter of seeing some splendid cold. Get that part of the equation here first and then we can worry about will it or won't it snow in my back yard later.:)

opr

**** that we have been waiting long enough with patience for snow. If it doesn't come we are going to wreck the forum.

Be warned Anonymous reads this forum and wants snow!

Opr

yorlum11

redsunset wrote: »

OK then, What we got so far. Well I think we can all agree that there will be strong push of very cold air from the heart of Siberia trying to make that long trek across the continent to our little Isle. It is great to watch its progress on the models as it is indeed a super cold air feed, however I keep seeing deflection after deflection as it gets near us. I do really wonder if it will make it all the way. Still early days at the moment and very promising but by no means a certainty.

Emotions I feel are going to be running high in here for the foreseeable future and understandably so. However lets not get the forum into a mental breakdown if the Beast from the east gets the door slammed shut.

This is our best chance of the entire winter of seeing some splendid cold. Get that part of the equation here first and then we can worry about will it or won't it snow in my back yard later.:)

Wise words!

Su Campu

I would hazard a guess that if one were to analyse the wording used in sean's work meeting today then what was probably said was that there are "no indications" of snow for the next 10 days. Now that is different to saying that "there will be no snow". They are stating the current status, which is that there is no reason to believe that we will get snow in the next 10 days - I think we can all agree on that, as that is the reason there have been about 10 pages of discussion on this thread today.

Check the minutes in the morning sean and report back! :cool:

Sponge Bob

Su Campu wrote: »

I think we can all agree on that, as that is the reason there have been about 10 pages of discussion on this thread today.

That plus the eternally gullible reading the hysterical permaramping on Netweather and feeling that this place is/should be another Netweather.

It ain't!!!! Too many sensible people who like evidence etc etc.

You wanna join in that ramping, join Netweather and leave us alone.

M.T. Cranium

I think the two key points going forward would be:

** increasing signs of a battleground scenario that sets up somewhere close to the west-central regions of Britain

** very low confidence in model ability to give accurate solutions past 96h

which taken together mean something like this:

** 40% chance that Ireland remains mild (after the 2-day cold spell)

** 30% chance that eastern Ireland gets into the battleground while the west stays mild

** 30% chance that all parts of Ireland turn much colder next week

Given that a large fraction of population live in the east, this would mean in sheer economic terms about a 50-50 chance of wintry disruption at some point next week. So while that's not a guarantee, it would seem like a risk to be closely monitored.

Any given set of model runs could really swing fast in one direction or the other, the Russian high, while massive, remains oriented in such a way that a fast push of cold air west is difficult, unless the centre shows signs of elongating into Sweden, then it could accelerate.

My hunch is that snow will come from this in about a week to ten days.

pistolpetes11

Sponge Bob wrote: »

That plus the eternally gullible reading the hysterical permaramping on Netweather and feeling that this place is/should be another Netweather.

It ain't!!!! Too many sensible people who like evidence etc etc.

You wanna join in that ramping, join Netweather and leave us alone.

Well then lets have them "sensible people" provide some discussion on the charts and whats happening, Cause its been like a morgue lately , I for one am delighted to see some activity in here.

No one thinks this should be another Netweather , but the simple facts are there is not much being offered in here in the way of topical discusion, there has been some cross posting, dont see how that is a bad thing

Or maybe they should just lock this place up and leave it invite only for the "sensible people"

pistolpetes11

M.T. Cranium wrote: »

I think the two key points going forward would be:

** increasing signs of a battleground scenario that sets up somewhere close to the west-central regions of Britain

** very low confidence in model ability to give accurate solutions past 96h

which taken together mean something like this:

** 40% chance that Ireland remains mild (after the 2-day cold spell)

** 30% chance that eastern Ireland gets into the battleground while the west stays mild

** 30% chance that all parts of Ireland turn much colder next week

Given that a large fraction of population live in the east, this would mean in sheer economic terms about a 50-50 chance of wintry disruption at some point next week. So while that's not a guarantee, it would seem like a risk to be closely monitored.

Any given set of model runs could really swing fast in one direction or the other, the Russian high, while massive, remains oriented in such a way that a fast push of cold air west is difficult, unless the centre shows signs of elongating into Sweden, then it could accelerate.

My hunch is that snow will come from this in about a week to ten days.

Sitting in well with your Winter forecast too !

Su Campu

For me, I am still against a proper easterly taking place, going on the ECMWF, UKMO and GFS northern hemispherical setup. The ECMWF and UKMO are fairly similar within their respective timeframes, showing fairly zonal conditions over North America slightly amplifying over the next few days, forming a low near Iceland that pumps high geopotential northwards towards the Norwegian Sea. This acts to sustain the Scandinavian high for a brief period, but the supply shuts off fairly quickly and a more zonal setup takes its place, dismantling the Scandi high somewhat.

The GFS is similar to a point but then does what it has a tendency to do - overdoes the amplification over North America, which holds the low pressure further west and allows the warm supply to continue for longer and building the High further west. This both holds its strength and also brings the cold over us. I don't think this will happen as the GFS is known for overdoing cold outbreaks.

As I've been saying, I reckon we will see some brief cold, but will see zonality win out.

pistolpetes11

Su Campu wrote: »

For me, I am still against a proper easterly taking place, going on the ECMWF, UKMO and GFS northern hemispherical setup. The ECMWF and UKMO are fairly similar within their respective timeframes, showing fairly zonal conditions over North America slightly amplifying over the next few days, forming a low near Iceland that pumps high geopotential northwards towards the Norwegian Sea. This acts to sustain the Scandinavian high for a brief period, but the supply shuts off fairly quickly and a more zonal setup takes its place, dismantling the Scandi high somewhat.

The GFS is similar to a point but then does what it has a tendency to do - overdoes the amplification over North America, which holds the low pressure further west and allows the warm supply to continue for longer and building the High further west. This both holds its strength and also brings the cold over us. I don't think this will happen as the GFS is known for overdoing cold outbreaks.

As I've been saying, I reckon we will see some brief cold, but will see zonality win out.

What do you think would need to change for us to get into a proper Easterly Flow ?

Or have the charts already gone to far beyond the situation for things to turn around ?

Su Campu

We need the GFS' cold amplification southwards into the western Atlantic for a change and not over the Canadian Maritimes, which is what we've had all winter. I can't see any reason why this will happen when the ECMWF and UKMO don't show it and the GFS is known for overdoing it. For me, the GFS may not be the one to watch for the longterm.

Just my opinion, but I've had it for a few days now.

BLIZZARD7

FI is very close at the moment- I can see clear differences at +72hrs when comparing one run to the last. This means that a small shortwave heading the wrong direction could completely throw any easterly potential off course- Equally it could be a small shortwave going in the right direction that acts as a trigger for any potential easterly. This is evident in numerous model runs this evening.

Another thing is that I would suggest people trust the UK Met FAX charts more than every new gfs run- reason being they have had professional forecasters examining all model output, before they are drawn up. Oh and one thing I have noticed is that as the FAX charts get closer to reality, the block is getting pushed further and further west. you can see this by watching fronts that are meant to be over england at +96hrs end up over the west of Ireland at +72hrs. This suggests to me that the models are underestimating the strength of the block.

I would have to disagree with su campu in that I believe that we will get a proper easterly- and if we do that it will last some length of time, not a quick switch back to zonality- The teleconnections/UK met office just do not support this notion.

*su campu probably knows far more than me about the weather and will end up right* We will see though ;D





Dan :cool:

Sponge Bob

pistolpetes11 wrote: »

Well then lets have them "sensible people" provide some discussion on the charts and whats happening

They have done this constantly...when something vaguely looked like happening. Heavy on the vague and on aspects of vague.

If it seems like nothing is happening that is probably because there is nothing happening....other than flip flopping GFS runs every 6 hours of course. (and we are talking Feb when we kinda suspect something could happen anyway)

Do you expect long posts in here saying, eg, "Hi There is nothing happening and here is a detailed list of what is not happening" or something ???

No amount of sqealing for something to happen will ever move a Siberian airmass into Dublin Bay. I will predict that much. :cool:

pistolpetes11

Sponge Bob wrote: »

They have done this constantly...when something vaguely looked like happening. Heavy on the vague and on aspects of vague.

If it seems like nothing is happening that is probably because there is nothing happening....other than flip flopping GFS runs every 6 hours of course. (and we are talking Feb when we kinda suspect something could happen anyway)

Do you expect long posts in here saying, eg, "Hi There is nothing happening and here is a detailed list of what is not happening" or something ???

No amount of sqealing for something to happen will ever move a Siberian airmass into Dublin Bay. I will predict that much. :cool:

There has and is plenty happening , anyway I'm off to my nest , tudalu

nacho libre

Su campu is right about the gfs overdoing cold only to usually back down in the end.
However, Alex Deakin( a bbc met office forecaster) who is by no means a cold fan, indicated that a proper easterly will take hold next week.
Of course he could still be wrong, but if the guys with the data we can't see, and who have an array of fancy supercomputers at their disposal, think an easterly will take hold, then it's at least grounds for optimism.

eskimocat

Well said Nacho.

BTW I was wondering... if the azore high pushing up on the charts towards Ireland has high temps of say 20c and it meets a low with temps of -24c coming from both east and west which would win out both been equal in size... (roughly)

Its just in one of the charts back the way there seemed to be much lower temps in the cold than higher in the high but the high pushed on up... Can someone explain how it does this? Is it getting help from the jet stream or something. I would love if someone could put this question into a better format for me! araghh

whataboutnow

whatever about people mentioning snow next week,we had a light flurry in Donegal recently,Hopefully we get a beefy shower as the previous was weak and short lived.Will be interesting

Fourteen

Sponge Bob wrote: »

...

Do you always have to be so negative? Lighten up.

monster1

its snowing here now in roscommon, big flakes!

whataboutnow

Looking through the boards in the last couple of weeks I've never seen as much whining and crying from people.I mean people's comments annoy me from time to time but I couldn't be AR_ED getting involved in petty squabble about who's right and who's wrong.I'm sure 90pc of people on the board agree,for the other 10 I'm sure they'll requote this and have a go.
happy quoting

delw

monster1 wrote: »

its snowing here now in roscommon, big flakes!

im sure you know the drill,pics or GTFO

derekon

Major downgrade for cold next Wednesday and Thursday on the ECM with mild weather coming in over Ireland and Britain.

But is anyone really surprised at that ? :rolleyes:

D