Winter Model Discussion 18Z 19/1/13 onwards.

[Argyle1980]

Ties in with the BBC forecast 5 minutes ago, they seemed to be talking down milder weather this weekend.

sky news seem to think its just going to be a mild blip before we go back to cold from the north east.

[smhouston]

Maybe i've jumped the gun in presuming the cold spell will end.

http://www.wetterzen...cs/Rtavn721.png

This is very different even at +72 as this run develops and tracks a SW SE!!

For now I shall refrain from reading too much into this but it will be interesting to see what the 12Z shows.

That's exactly what I meant yesterday when I said to you how can you trust the models so far in advance when they've struggled so badly.

It could just be the 6z showing itself up again, but personally I shall be taking all the models outputs with a pinch of salt until a lot nearer the time

[Cheese Rice]

The GFS doesn't suggest a return to milder weather for northern and central areas. Using the GFS maximum temperature prediction for Leeds at 3pm we see..

Friday 25th: 1.c

Saturday 26th: 0.c

Sunday 27th: 2.c

Monday 28th: 2.c

The cold must be entrenched without sufficient mixing at the lower layers to raise temps. The south looks like it'll be struggle to hold onto the colder temps though.

Edited January 21, 2013 by Cheese Rice

[Frosty.]

sky news seem to think its just going to be a mild blip before we go back to cold from the north east.

Does GP work for sky news then

[Argyle1980]

Does GP work for sky news then

it was just the thought of Abigail Lang the weather girl .

[chris55]

Well I did think the mild push from the south west was a done deal as we head towards the weekend, but seeing the 06 z GFS vs the ECM it doe make you wonder, GFS trending the energy south east as the timeframe comes closer? Where have we seen that before!

GFS midnight Friday, not really especially cold or anything, but interesting, with some undercutting going on.

ECM for the same time frame, long fetch south westerly in the making.

[Catacol]

Well - an avowed coldie here... but nothing in the output to make me change my views from yesterday.

CPC 8 - 14 dayer (from yesterday) looks poor:

7 day ECM ensemble average looks even worse:

And the op runs are all dreadful. Take your pick - here is GFS for 7 days

And here is UKMO for 6 days:

I am amazed there is so much optimism around here this morning. Op runs and mean runs are all saying no. GP's call of height rises at the weekend looks a long shot at present. Look at the NH chart at the moment and the emptying of the canadian vortex into the atlantic looks nailed and the energy doesnt look to be going anywhere fast to me. Pulling an op run at 384h and saying "look - a greenland high!!" is more optimistic than me going and putting £10 on Scotland winning the 6 Nations this year... and that's saying something.

Hoping for something much more tangible than the tea leaves some are staring at this morning. Not to say it wont happen of course - a change in output I mean - but right now the output is dreadful plain and simple.

Edited January 21, 2013 by Catacol_Highlander

[Frosty.]

Well - an avowed coldie here... but nothing in the output to make me change my views from yesterday.

CPC 8 - 14 dayer (from yesterday) looks poor:

7 day ECM ensemble average looks even worse:

And the op runs are all dreadful. Take your pick - here is GFS for 7 days

And here is UKMO for 6 days:

I am amazed there is so much optimism around here this morning. Op runs and mean runs are all saying no. GP's call of height rises at the weekend looks a long shot at present. Look at the NH chart at the moment and the emptying of the canadian vortex into the atlantic looks nailed and the energy doesnt look to be going anywhere fast to me. Pulling an op run at 384h and saying "look - a greenland high!!" is more optimistic than me going and putting £10 on Scotland winning the 6 Nations this year... and that's saying something.

Hoping for something much more tangible than the tea leaves some are staring at this morning. Not to say it wont happen of course - a change in output I mean - but right now the output is dreadful plain and simple.

I don't think the met office use tea leaves when they say the cold is set to return in Feb, don't think gp or chio use tea leaves either, nuff said

My view is this less cold/milder blip was always on the cards since we are in the uk and not canada, but I also think the most severe is yet to come as the fallout from the recent strat warming continues to downwell.

[starstream]

I don't think the met office use tea leaves when they say the cold is set to return in Feb, don't think gp or chio use tea leaves either, nuff said

My view is this less cold/milder blip was always on the cards since we are in the uk and not canada, but I also think the most severe is yet to come as the fallout from the recent strat warming continues to downwell.

I am new and dont usually post in this thread....Waaaay too scary!!

But I have read,that there is a lag between strat warming,and the then effects,and then in other posts,there is no noticable lag effect....

which is correct~?,or in this instance as we has a warming event in Dec, will the recent larger warming event be less "noticable"as we still have disuruption by Dec warming?

hope that makes sense

[Frosty.]

I am new and dont usually post in this thread....Waaaay too scary!!

But I have read,that there is a lag between strat warming,and the then effects,and then in other posts,there is no noticable lag effect....

which is correct~?,or in this instance as we has a warming event in Dec, will the recent larger warming event be less "noticable"as we still have disuruption by Dec warming?

hope that makes sense

I'm no expert on strat warming but I think there are phases, peaks and troughs and we are currently in a peak but next week will be in a trough but from what I understand from the real experts on here, the most severe wintry weather is still to come in about a few weeks time, this is just the bowl of soup before the main course.

[bluearmy]

more interesting solutions from the 06z gefs suite and some of them far earlier than previous runs. some may not be able to see the direction of travel here but it seems pretty obvious to me. less cold - yes. how much less cold? no idea. how long for? probably not very long.

[nick sussex]

The GFS 06hrs certainly throws a curveball into a milder weekend but doesn't have any operational support from the other models.

Ãf you look upstream to the ne USA it develops a shortwave around 96hrs which is quite amplified this helps pull back some of the energy heading east and as this phases with the low heights to the nw helps kick that shortwave se through the UK.

You'd still need a westwards correction in the pattern though even with this new trend. I'd say for the timebeing its an outlier solution, we'll know this evening whether it gathers any more support.

[Summer Sun]

Well it looks like the cold spell is coming to an end

ECM shows the Atlantic breaking through at the weekend and into next week

Today's met office update just about confirms that this cold spell is coming to an end

During next week, changeable, milder weather seems likely with spells of cloudy wet weather interspersed with brighter skies and showers. However, there may still be some snow over high ground with a chance of below average temperatures again later in the period.

Edited January 21, 2013 by Gavin.

[starstream]

I'm no expert on strat warming but I think there are phases, peaks and troughs and we are currently in a peak but next week will be in a trough but from what I understand from the real experts on here, the most severe wintry weather is still to come in about a few weeks time, this is just the bowl of soup before the main course.

well lets hope its cold soup,followed by an iceberg salad......with sorbet to finish!

thanks for not ignoring a.novice question.

[Alexis]

Well - an avowed coldie here... but nothing in the output to make me change my views from yesterday.

CPC 8 - 14 dayer (from yesterday) looks poor:

7 day ECM ensemble average looks even worse:

And the op runs are all dreadful. Take your pick - here is GFS for 7 days

And here is UKMO for 6 days:

I am amazed there is so much optimism around here this morning. Op runs and mean runs are all saying no. GP's call of height rises at the weekend looks a long shot at present. Look at the NH chart at the moment and the emptying of the canadian vortex into the atlantic looks nailed and the energy doesnt look to be going anywhere fast to me. Pulling an op run at 384h and saying "look - a greenland high!!" is more optimistic than me going and putting £10 on Scotland winning the 6 Nations this year... and that's saying something.

Hoping for something much more tangible than the tea leaves some are staring at this morning. Not to say it wont happen of course - a change in output I mean - but right now the output is dreadful plain and simple.

Depends how you define dreadful though, and what they're saying 'no' to. We're not looking at a couple of weeks of 12C IMO, like in December. And we're certainly not in a situation of looking at 168h and using the words 'nailed on'.

[nick sussex]

Interesting!

I've just looked again at the UKMO 96hrs, indeed it does desperately try and undercut with the shortwave near Iceland but doesn't quite manage it.

So there maybe a little support for the GFS 06hrs trend, regardless of this more shorter term interest it's still likely to be just a temporary delay to milder conditions as that energy heads east from the weakening PV in Canada.

Interesting also the NM on the BBC phrases the weekend as an attempted breakdown in the cold, perhaps I'm reading too much into this but given the output you' think it would have been a simple turning milder .

[TEITS]

more interesting solutions from the 06z gefs suite and some of them far earlier than previous runs. some may not be able to see the direction of travel here but it seems pretty obvious to me. less cold - yes. how much less cold? no idea. how long for? probably not very long.

Indeed how long is the big question?

At the moment combined with what GP says, Met O update, GEFS ensembles, GFS Ops then between 27th Jan to 4th Feb a respite from the cold weather with the chance of this returning from the 4th onwards. Obviously these dates could change but I feel around 7 days respite is what we're looking at.

Personally im pleased we will have a respite. Currently have around 8 inches of snow outside and im stranded.

[Frosty.]

I think the gfs 06z is a better run than the 00z because it delays the change and there is trough disruption on saturday with some snow around, beyond that we do get a few milder days but the angle of the jet is better in FI with more of a nw/se slant which would bring in some colder incursions with wintry showers and less mild sectors, hopefully the 6z is on the right track, much better than the gfs 00z especially.

Edited January 21, 2013 by Frosty039

[Cloud 10]

Interesting!

I've just looked again at the UKMO 96hrs, indeed it does desperately try and undercut with the shortwave near Iceland but doesn't quite manage it.

So there maybe a little support for the GFS 06hrs trend, regardless of this more shorter term interest it's still likely to be just a temporary delay to milder conditions as that energy heads east from the weakening PV in Canada.

Interesting also the NM on the BBC phrases the weekend as an attempted breakdown in the cold, perhaps I'm reading too much into this but given the output you' think it would have been a simple turning milder .

Quite a difference around the Iceland area on the latest fax chart for thursday compared to

the one issued last night,the block not allowing energy to break through.

last night.. today..

[nick sussex]

Quite a difference around the Iceland area on the latest fax chart for thursday compared to

the one issued last night,the block not allowing energy to break through.

last night.. today..

Yes and even though the BBC are now mentioning milder by the weekend the UKMO update suggests snow for the east and south as that happens.

So certainly you'd have to have some trough disruption for that, the UKMO hints at that, the GFS 06hrs goes for it , the ECM doesn't although NOAA think it might be too quick to eject energy eastwards out of Canada as the PV breaks down.

Looking at the UKMO 96hrs:

I'd say snow prospects for the weekend will be increased if the models develop that shortwave out of the ne USA more, circled red, if they also amplify that more this will help pull back the energy nw near Iceland and sharpen the approach to eject that shortwave near Iceland circled black se further west.

I think eventually even with that the odds strongly favour milder conditions next week but lets see if we can squeeze out a bit more snow before that happens!

[Sleet30031972]

Right this is how I see it!

Latest fax charts and the 06z suggest a major change to me. Slightly milder on Sat yes but then polar vortex to intensify and pull southwards. Troughing features then to spill over from the low pressure system over Newfoundland causing a major undercut over UK with deep cold feeding in from the east. Back in the freezer - game on!

[Mark Neal.]

So models firming up on the atlantic trying to make sufficient progress through the weekend. Although some changes would allow perhaps a snowy breakdown. I for one, am happy with this cold spell, had 2 snow events, and got 16cm from them. I need to get to Manchester next Wednesday to see the footie, so need better weather. More wet & windy weather could prevail through next week, although after that i think we may start to see pressure trying to build up into Greenland, thereafter a cold spell from the N/NE looks a good bet, as GP & Others have alluded too. Fun & Games over the next few days to see if we can get a snowy breakdown, other than a switch to mild & wet.

[Frosty.]

Right this is how I see it!

Latest fax charts and the 06z suggest a major change to me. Slightly milder on Sat yes but then polar vortex to intensify and pull southwards. Troughing features then to spill over from the low pressure system over Newfoundland causing a major undercut over UK with deep cold feeding in from the east. Back in the freezer - game on!

I hope that's how the meto see it

[Cheshire Freeze]

Interesting to note that after a week or so of milder, wetter weather both the CFS monthly and 9 monthly are very keen to introduce some severe wintry episodes via stronger Greenland-Scandi blocking post the 300 hr mark.

Really quite a signal for strong northern blocking and southerly tracking lows on the anomaly charts I've just looked at.

I'll also add I'm seeing some consistency in the usually inconsistent GFS FI. That consistency is some form of blocking centred around Greenland in deep FI (first week of February)

Edited January 21, 2013 by CreweCold

[TheBigFreeze]

Interesting to note that after a week or so of milder, wetter weather both the CFS monthly and 9 monthly are very keen to introduce some severe wintry episodes via stronger Greenland-Scandi blocking post the 300 hr mark.

Really quite a signal for strong northern blocking and southerly tracking lows on the anomaly charts I've just looked at.

are these more reliable in the time frame you are talking about or is it still to be considered FI??