General Model Output Discussion

[danm]

General trend becoming clearer now.

Once the LP clears we see a shortlived ENE,ly. However this isn't going to be a classic E,ly with heavy snow showers in E areas. What happens beyond this is it remains fairly dry and very cold with the exception of Scotland who might see more prolonged snow due to the SW.

Beyond this and the flow changes towards to a slack N/NW,ly but remaining mainly dry and very cold. After this we see a LP system tracking S but to be honest im going way too far ahead.

At the moment if your after snowfall then it looks as though your best chance is via this LP. Otherwise I cannot see much potential for snowfall with the exception of E Scotland. However in saying this surprise snowfall often comes along and im not 100% the models have +168 to +240 correct yet.

So you arent expecting much convective snowfall off the north sea for areas further south?

[Guest North Sea Snow Convection]

I expect there will be some snow left on the front as it moves away south, but amounts are not likely to be as much as the mid week period for the central zone. Some snow showers around on Friday though especially for favoured eastern and south eastern areas

Edited December 28, 2009 by North Sea Snow Convection

[winter watcher]

General trend becoming clearer now.

Once the LP clears we see a shortlived ENE,ly. However this isn't going to be a classic E,ly with heavy snow showers in E areas. What happens beyond this is it remains fairly dry and very cold with the exception of Scotland who might see more prolonged snow due to the SW.

Beyond this and the flow changes towards to a slack N/NW,ly but remaining mainly dry and very cold. After this we see a LP system tracking S but to be honest im going way too far ahead.

At the moment if your after snowfall then it looks as though your best chance is via this LP. Otherwise I cannot see much potential for snowfall with the exception of E Scotland. However in saying this surprise snowfall often comes along and im not 100% the models have +168 to +240 correct yet.

So where is the likes off Blast and Other respected forecasters getting this very severe cold spell from? I quote from Blast who i very much respect his forecasts saying. A severe cold and very wintry spell off weather from new years onwards too last for around three weeks come from this is really confusing the hell out off me. :unsure: He did also mention blizzards

Edited December 28, 2009 by winter watcher

[Geordiesnow]

Not sure if i agree with TETIS regarding the easterly being dry, i think one of the reasons why the GFS has so little PPN at first is because as they are predicting the front being too far North, it leaves quite a bit of cloud therefore convective showers don't develop that well.

UKMO PPN charts can often tell a false story and always for whatever reason understrengths how much PPN is when it comes too North Sea shower clouds.

One of the main reasons why i wanted the low further south so for my location at least can be in the colder air and have the convective activity.

Edited December 28, 2009 by Geordiesnow

[TEITS]

So where is the likes off Blast and Other respected forecasters getting this very severe cold spell from? I quote from Blast who i very much respect his forecasts saying. A severe cold and very wintry spell off weather from new years onwards too last for around three weeks come from this is really confusing the hell out off me.

Well the general trend appears to be that the AO will remain negative for the next few weeks. The blocking we see over Greenland could back W and we see a shortlived milder spell. However as GP says this blocking could move E to W and then W to E bringing a return of the colder weather.

I really wouldn't worry about +168 to +240 at the moment though because this timeframe can see many changes.

[AtlanticFlamethrower]

At the moment if your after snowfall then it looks as though your best chance is via this LP. Otherwise I cannot see much potential for snowfall with the exception of E Scotland. However in saying this surprise snowfall often comes along and im not 100% the models have +168 to +240 correct yet.

I was thinking the same thing, TEITS. Lots of excitement about the return of cold could turn to disappointment over the lack of widespread frontal PPN.

London looks like it will stay dry but cold except for the rain Tuesday/Wednesday.

Doesn't look like a "classic" set-up for snow yet.

[Solar Cycles]

Not sure if i agree with TETIS regarding the easterly being dry, i think one of the reasons why the GFS has so little PPN at first is because as they are predicting the front being too far North, it leaves quite a bit of cloud therefore convective showers don't develop that well.

UKMO PPN charts can often tell a false story and always for whatever reason understrengths how much PPN is when it comes too North Sea shower clouds.

One of the main reasons why i wanted the low further south so for my location at least can be in the colder air and have the covective activity.

I disagree, this will be a very cold, but dry spell for most within the reliable time frame. Think it will be mid January before snow becomes more widespread, but that is way out in FI!

[J10]

Well the general trend appears to be that the AO will remain negative for the next few weeks. The blocking we see over Greenland could back W and we see a shortlived milder spell. However as GP says this blocking could move E to W and then W to E bringing a return of the colder weather.

I really wouldn't worry about +168 to +240 at the moment though because this timeframe can see many changes.

They haven't even nailed T+6 yet.

[swilliam]

At last an honest assumption, never expected any snow living on the south coast in Poole, and doubt to see any in the near future, 1cm in the last ten years has led to utter contempt of promising model outputs anyway good luck to those who do.

You just do not what is going to happen once the cold air is established. All kinds of small features develop and produce snow. There is also still the possibility of channel lows (as is alluded to by the UKMO 15 day outlook). The GFS control has a very nice example at T216.

So I would not get so down yet. One thing is for sure - no cold = no snow.

[TEITS]

They haven't even nailed T+6 yet.

Im beginning to wish I never said anything.

I just want to clear something up though. When I say a classic E,ly im referring to at least 3 days of non stop convection off the N Sea. This I do not see and the general theme from the models is for the blocking over Greenland to back W. However im not suggesting there won't be any convection as there might be a 24-36hr window of opportunity.

I apologise if I was misleading.

[SnowBallz]

I'm stuggling to understand what's supposed to be so exciting about a dry cold? It's VERY boring if you ask me I'd rate it alongside dull SW'ly rubbish

[winter watcher]

Well the general trend appears to be that the AO will remain negative for the next few weeks. The blocking we see over Greenland could back W and we see a shortlived milder spell. However as GP says this blocking could move E to W and then W to E bringing a return of the colder weather.

I really wouldn't worry about +168 to +240 at the moment though because this timeframe can see many changes.

So for the record you are not buying the likes off Blasts and Joe B's forecast i must admit i am pretty surprised really the fact is atm i do agree with Blasts and Joe b's Forecasts not just because i love cold and snow but simply because over the past year they have both never been far off the mark in terms off down the line projections. Appreciate your response TEITS

[Matt12]

I'm stuggling to understand what's supposed to be so exciting about a dry cold? It's VERY boring if you ask me I'd rate it alongside dull SW'ly rubbish

Actually I'd prefer mild rubbish as at least we wouldn't have to shiver for nothing!!

Precip changes quickly though. No one can tell how much precip we will get in 5 days' time, let alone a week or 2. Also, we have gone from poor charts to armageddon type scenarios back to poor charts all in one day!! Kinda sums up the uncertainty imo.

Edited December 28, 2009 by Matt12

[rmc1987]

I'm stuggling to understand what's supposed to be so exciting about a dry cold? It's VERY boring if you ask me I'd rate it alongside dull SW'ly rubbish

Well we are in for a fair bit of cold rain over Tues/Weds...!

[Optimus Prime]

I really can't get anything knowledgeable out of this discussion because there are a few that go on about 'FI' all the time knowing perfectly well at that time frame anything can happen.

The outlook remains as much as what it did a week ago. Very cold.

Actually I'd prefer mild rubbish as at least we wouldn't have to shiver for nothing!!

You go on about the weather and climate like it's something despensable. 'Enjoy the weather, it's the only weather you got' - Joe Bas*ardi

[rmc1987]

So for the record you are not buying the likes off Blasts and Joe B's forecast i must admit i am pretty surprised really the fact is atm i do agree with Blasts and Joe b's Forecasts not just because i love cold and snow but simply because over the past year they have both never been far off the mark in terms off down the line projections. Appreciate your response TEITS

I know I'm not buying them. Replace the word snow with rain then it's a bit more believable! Since he was on about the South, the way I see it is Wales/Midlands are the guys that need to be alert!

Edited December 28, 2009 by rmc1987

[SnowBallz]

Well we are in for a fair bit of cold rain over Tues/Weds...!

Cold rain?? I've never felt warm rain!

I don't mind it getting seriously arctic for a while but only if we get something interesting like a good bit of snow. Otherwise I just don't see what's to get excited about really. Dry cold is just depressing!

[Thundery wintry showers]

General trend becoming clearer now.

Once the LP clears we see a shortlived ENE,ly. However this isn't going to be a classic E,ly with heavy snow showers in E areas. What happens beyond this is it remains fairly dry and very cold with the exception of Scotland who might see more prolonged snow due to the SW.

I think this only holds true for the southern half of England. 31 December, 1 and 2 January all look like they have significant potential to deliver a fair amount of convection for eastern Scotland and north-east England.

3+ days of non stop convection off the North Sea is actually quite rare- while it has happened in the past, it's also quite common that after a couple of days of convection from the North Sea, a more stable feed establishes giving dry cloudy weather. This happened around New Year 1997 in Tyneside for example- I remember two days of sunshine and snow showers on 30 and 31 December, then it turned dry and cloudy by the 1st January. The models currently show the other common way the convection can be halted- namely a build of pressure from the north. But the main thing that limits the length of convective potential towards south-east England is the frontal band hanging around for a few days beforehand.

[The PIT]

I thought we were discussing models not alternative forecasts. Joe B is as about as reliable as a Piers C and nearly always wrong. Anyway ECM keeps the cold run but in deep FI land seems to head for no mans land but no sign of anything mild there.

GEM following GFS and ECM so pretty good agreement up to T72 hours at least.

Certainly looks like the cold spell continuing into the new year making this one of the longest cold spells of recent years.

[winter watcher]

I know I'm not buying them. Replace the word snow with rain then it's a bit more believable! Since he was on about the South, the way I see it is Wales/Midlands are the guys that need to be alert!

[/quot

At the end off the day it everyone to their own i guess. But when you have most senior forecasters supporting the evolution in which i was referring to you do feel secure that their is a good chance off the discussed weather pattern emerging and especially when they have been consistently accurate over a long period off time

[AtlanticFlamethrower]

However im not suggesting there won't be any convection as there might be a 24-36hr window of opportunity.

I apologise if I was misleading.

based on what the charts show, I don't think you were misleading. 24-36 hrs of showers will cover only a tiny area under the favourable wind direction. this snow will not be newsworthy and disruptive only in local areas.

absent from the ECM is a channel low vs established cold battleground scenario, true easterly, or true north easterly. the ECM north westerly scenario ends with a Euro high. no reason to hype this event - yet.

[Cableguy]

Cold rain?? I've never felt warm rain!

I don't mind it getting seriously arctic for a while but only if we get something interesting like a good bit of snow. Otherwise I just don't see what's to get excited about really. Dry cold is just depressing!

isnt this the model output thread??????

[MR EXTREMES]

So where is the likes off Blast and Other respected forecasters getting this very severe cold spell from? I quote from Blast who i very much respect his forecasts saying. A severe cold and very wintry spell off weather from new years onwards too last for around three weeks come from this is really confusing the hell out off me. :wallbash: He did also mention blizzards

i think it might help if people read ian f post from earlier.

even he talked of possible blizzard in the south of england.

Edited December 28, 2009 by badboy657

[TEITS]

So for the record you are not buying the likes off Blasts and Joe B's forecast i must admit i am pretty surprised really the fact is atm i do agree with Blasts and Joe b's Forecasts not just because i love cold and snow but simply because over the past year they have both never been far off the mark in terms off down the line projections. Appreciate your response TEITS

I would agree with Joe B/BFTP in respect that much of Jan will be cold. However I don't agree that it will be severe blizzards every day. This would be very unusual and apart from 1947 no other cold spell has ever delivered this. What you have to remember is even the cold winters of 1963 has spells of dry, very cold weather.

Based on the models I would say from tomorrow until the Weekend there is the risk of snow for everyone with the heaviest falls being W Midlands/N Wales. Beyond the weekend into next week remaining very cold and mainly dry but obviously some places might be at risk of snowfall due to disturbances that haven't been correctly modelled yet.

At the moment alot depends on whether the block over Greenland does back W or remain in situ.

[cooling climate]

I would think that many locations will see several ice days ( max temps below freezing) once the freeze sets

in (probably 1st onwards). I would also not be surprised to see this very cold spell last for a lot longer than

the models are currently showing and with this more chances for snow than the current model outputs are

portraying.

As far as the next two to four days are concerned you can guarantee there will be surprises in store with

some areas expecting snow and getting rain and vice versa or not expecting anything and ending up with

a nice covering of snow.

I remember well the Thursday the 5th of Feb this year when the met released severe weather warning

mid evening of up to 20cm of snow for my locale and within two hours max of this warning being given everything

had changed with the low stalling out west and poster West is Best location picking up over 60cm of snow.