Model Output Discussion 1st January 2014-06z onwards.

[Cheshire Freeze]

Well if the models dont improve this evening am afraid where looking at maybe a new trend where more energy will be goin north east!!fingers crossed but its going to be a long day!!

 

I'll be going work soon so I'll be away from the inevitable Netweather model thread carnage!

[gottolovethisweather]

Yes, we're in danger (on this run) of forming one large mid latitude block across the UK, whilst the Atlantic creeps in slowly from the NW......and that would be painful.

 

Albeit at t+200 odd hours? What goes before is tasty, if not yet perfect. Timeframe for watching has to be where FI currently lies within say, t+108 to t+168 hours.

Edited January 9, 2014 by gottolovethisweather

[garbagebags]

Well people always say look for trends and not individual runs. Well unfortunately the trend (all be it only the past 48 hours) is pushing the whole system further and further east. 

[Cheshire Freeze]

Albeit at t+200 odd hours?

 

We don't get the cold until 180 hrs lol!

[Cecil Hogmanay Melchett]

At least gfs06z gives the chance of snow mainly for the north but not exclusively so.

Fingers crossed we see a correction south of the jet and then the opportunity for snow more widely.

UKMO in particular is a concern, will be very interesting to see the meto update but their call yesterday of snow mainly over northen hills looks pretty spot on.

[Ali1977]

The South look at doing best with regards snow in the cold spell, the Easterly winds stick around for a while, maybe a 4 day spell with snow/snow showers still possible going off the latest run.

[gottolovethisweather]

Seen enough, Atlantic high is going to muscle in here and drag everything S before it even properly gets going. Poor 6z TBH

 

Sorry CC, isolating you twice for comment but why is this the above chart not good for us coldies? Scandi High, check. Blocked Atlantic, check. A flow from the NW, possibly North, check.   Yes it is only the GFS 6z granted, but this afternoon and evening suites and tomorrows will be much more revealing. Let's not lose sight of what is to become a pattern changer, how long for is a much more pertinent question and I guess, that's where your concern lies, i.e. at 8 to 10 days out.

Edited January 9, 2014 by gottolovethisweather

[johnholmes]

Very good point. However summer rainfall isn't a very good example because they were isolated thunderstorms which is a completely different beast and impossible to predict where they will spring up exactly. Fronts are much more predictable. 

 

not at all, I was taking into account ALL types of precipitation, frontal and showery. Believe me frontal systems are notoriously difficult to get the timing let alone the intensity correct.

[gottolovethisweather]

We don't get the cold until 180 hrs lol!

 

Thanks. See my post above.

[Ali1977]

Ian F on twitter saying the Express headlines ( another cold one ) often become damp squibs...."as it may indeed become"

Edited January 9, 2014 by Ali1977

[offerman]

I have a good Memory. Full Credit once again to I.F for he said sometime ago when answering various questions that he couldn`t see any cold near term(this was way back in December) however he said 2nd week in to January could see things change.

 

I know forecasters generally say anything more than a week ahead is pinch of salt but some how he does manage to predict trends way advance of this and get it right more often then not.

 

Also remember him doing this a few times during the last few colds spells last couple years.

 

Credit where dredit due i say.

 

So thanks I.F for taking the time to post on these threads.

[Cecil Hogmanay Melchett]

On reflection i think most of us would BANK GFS06z,its a slow burner but the trnd is the friend and both GFS runs today offer the posibilty of snow acorss much of the UK,im that desprtate for snowi'll take pretty much ANYTHING as it stands,even if its for one day

Ian F on twitter saying the Express headlines ( another cold one ) often become damp squibs...."as it may indeed become"

Hmmm sounds a bit ominous does that.

Maybe Ian will drop in at some point to offer some more professional guidance on the picture as it stands..

[johnholmes]

552 line Appearing over Finland. Low over France not really helping. Maybe continent is just too warm still? Give me a greeny any day. 

 

 

 

552 over Finland=?=it is part of the high some of you are praying for to block the eastward march of the Atlantic and has little to do with what surface temperatures will be over Finland

[tight isobar]

Well a fare bit of weight rides on the shoulders of the 12z cross today. As again I think theres where the beginning of a more solid prognosis may begin to evolve. Its a knife edge as it gets right now!.

[Downpour]

East/west biases on this forum are possibly colouring the views of some members (I do exactly the same). Members in the west won't be happy with today's runs for obvious reasons, while eastern members are probably more relaxed about them. IMO we need to see the whole shebang shunt a bit west because it's too risky a setup at the moment, even here in the east. Certainly a general downgrade today so far, although it could quite easily revert. 

 

@JohnHolmes – it's the model thread so it's perfectly valid to comment on the progged location and type of ppn, the thumping caveat that ppn forecasts at this range are unreliable notwithstanding. My fear at the moment is that the North Sea gets smashed by snow while the UK gets yet another soaking. 

Ian F on twitter saying the Express headlines ( another cold one ) often become damp squibs...."as it may indeed become"

That's a very nasty little update from Fergie. Not good news for coldies. 

[The PIT]

Oh dear looks like the trend is backwards. GFS further downgrade and push back I think my first air frost of the winter is still there though. Just doubled checked it is.

[johnholmes]

 

@JohnHolmes – it's the model thread so it's perfectly valid to comment on the progged location and type of ppn, the thumping caveat that ppn forecasts at this range are unreliable notwithstanding. My fear at the moment is that the North Sea gets smashed by snow while the UK gets yet another soaking. 

sorry won't let me post below your post but you argue precisely why I constantly urge caution. Of course folk can discuss it all I am trying to do is explain, maybe badly, that predicting what falls from the sky beyond about 24 hours is fraught with forecast problems, whatever type and snow simply makes it very much more complex. There are EIGHT variables to consider not 1 or 2.

 

[shedhead]

06a delivers in the end. By next Sunday the block has orientated sufficiently to give a NE flow under -8c uppers giving widespread snow showers to most. looks like the PV to our north is strong enough to evebtualy topple the block though unfortunately. If we had seen this run 3 weeks ago though we would be jumping for joy!

Not singling you out in any way here Tim, but how often do we see this type of post in this type of situation? What we definately do not want to see here is any really good synopotics flatly refusing to come inside T+144hrs, because when that kind of trend develops it tends to lock itself in, so as others have said the coming 24-36hrs looks pivotal in deciding what kind of bite this first cherry of Winter gets. 

[Purga]

East/west biases on this forum are possibly colouring the views of some members (I do exactly the same). Members in the west won't be happy with today's runs for obvious reasons, while eastern members are probably more relaxed about them. IMO we need to see the whole shebang shunt a bit west because it's too risky a setup at the moment, even here in the east. Certainly a general downgrade today so far, although it could quite easily revert. 

 

@JohnHolmes – it's the model thread so it's perfectly valid to comment on the progged location and type of ppn, the thumping caveat that ppn forecasts at this range are unreliable notwithstanding. My fear at the moment is that the North Sea gets smashed by snow while the UK gets yet another soaking. 

That's a very nasty little update from Fergie. Not good news for coldies. 

Aren't you reading far, far too much into evey tiny snippett of an utterance from Ian F? The evolution may indeed turn into a damp squid, there again it may not!

[UV-RAY]

East/west biases on this forum are possibly colouring the views of some members (I do exactly the same). Members in the west won't be happy with today's runs for obvious reasons, while eastern members are probably more relaxed about them. IMO we need to see the whole shebang shunt a bit west because it's too risky a setup at the moment, even here in the east. Certainly a general downgrade today so far, although it could quite easily revert. 

 

@JohnHolmes – it's the model thread so it's perfectly valid to comment on the progged location and type of ppn, the thumping caveat that ppn forecasts at this range are unreliable notwithstanding. My fear at the moment is that the North Sea gets smashed by snow while the UK gets yet another soaking. 

That's a very nasty little update from Fergie. Not good news for coldies. 

I think Ian is just reiterating how much uncertainty remains in the outlook.

[Tim Bland]

Not singling you out in any way here Tim, but how often do we see this type of post in this type of situation? What we definately do not want to see here is any really good synopotics flatly refusing to come inside T+144hrs, because when that kind of trend develops it tends to lock itself in, so as others have said the coming 24-36hrs looks pivotal in deciding what kind of bite this first cherry of Winter gets. 

 

I agree 100% It is a bit dissapointing that yesterday we were taling about snow for early next week, now it is the end of next week. Often we see cold spells getting pushed back and the longevity shortened until all we get is a few sleety showers on the east coast. fingers crossed this cold spell wont take that path but it is something that people should bear in mind before rushing to tell the world to get their sledges ready!

Edited January 9, 2014 by Tim Bland

[shedhead]

I agree 100% It is a bit dissapointing that yesterday we were taling about snow for early next week, now it is the end of next week. Often we see cold spells getting pushed back and the longevity shortened until all we get is a few sleety showers on the east coast. Singers crossed this cold spell wont take that oath but you never know!

Indeed Tim, you only have to think back to the northerly that never was in late November for a perfect example. What looked like providing a widespread snow event for the north and even some wintryness for the south only 3 or 4 days prior ended up as a few sleet showers in Shetland, so we have to remain guarded. Looking at the latest T+144hr though (which is still as far ahead as I feel it's prudent to look) the overall pattern still looks pretty good for cold imo, with the Scandi HP ridging west into Greenland...that will do for now.

 

Edited January 9, 2014 by shedhead

[johnholmes]

re the snow early next week. This was in all honesty more hopecasting interpretations on model output rather than sound meteorological reasoning. It is going to get colder 100%: how much colder and how much frost and snow and for how long are very much up in the air, or that is my interpretation of lookng at ANY model output over the past 4-5 days.

 

and the comment above from shed

that will do for now.

is the sensible way of looking at it in my view

Edited January 9, 2014 by johnholmes

[IDO]

The ECM ensemble for London:  

 

Certainly the mean temp suggests a colder 7-10 days IMBY. The op appears to follow the less cold options from D7, where as the mean trend still shows a slow fall in temp.

 

Lots of potential there, and clarity will come with more runs.

[Thundery wintry showers]

I feel that over the next week or two, the inputs of continental air will only reduce temperatures to near or slightly below average levels at times (not low enough for widespread snowfall) because the lows coming in off the Atlantic will keep us in a south-easterly or southerly flow, which will keep the colder air locked away to the north-east.  Sunshine amounts are often low in this type of setup, as we get the cloud associated with frontal systems and cloud from the North Sea associated with stratocumulus trapped underneath a cap.

 

Certainly, the 8-14 day update from NOAA doesn't suggest that the blocking high to the NE will make significant westward progress to the north of Britain:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

 

However, I think we're in with a fair chance of a cold snowy blast in the last third of January as there is quite a strong signal for high pressure to move eastwards from the mid-Atlantic and this could merge with the high pressure to the N and NE.