[Hunt For Cold: Model Discussion - Heading Into Christmas]

1 hour ago, s4lancia said:

Quick Tropospheric Response.

in other words, how quickly the weather in the troposphere gets influenced by the SSW event as it propagates downwards from the stratosphere.

Thanks, @s4lancia

[Hunt For Cold: Model Discussion - Heading Into Christmas]

4 minutes ago, winterof79 said:

Thanks Blue.

I heard that the QTR/Warming was already being felt over Eastern Asia with a 1055Mb High.

There is just something that tells me that the charts below could well upgrade at short notice

Here are a couple of GEFS for that time 

All very interesting WRT the SSW and what we are dealt with.

 

Someone please a QTR as there is no explanation link under this term? MOD team can this be updated for folks like me who are only dipping in and out these days. I'm guessing it's something to do with stratospheric processes.

[Hunt For Cold: Model Discussion - Heading Into Christmas]

1 hour ago, Ladyofthestorm said:

I am not so sure the High will hang on like a limpet.

The ensembles are telling a very different story. Trend is the friend. High pressure eroded away allowing the cold in.  The 850s suggest a gradual decrease in temps as the process continues. 

 

It is a waiting game. A significant SSW has taken place, zonal winds expect to reverse. I would imagine it will be a Nly first then Easterly or NE

 

 

Agreed

[Hunt For Cold: Model Discussion - Heading Into Christmas]

1 hour ago, karlos1983 said:

Aye certainly is! Although so far this winter it’s been a bit like trying to hook a Barracuda in the English Channel  

Well, the Blue-fin Tuna are arriving so hope springs eternal. Hunch, nothing more nothing less really, the second week of January so D10 through D14 is where we should be looking for repeating trends, I reckon.

[Hunt For Cold: Model Discussion - Heading Into Christmas]

1 hour ago, Ali1977 said:

4/5 good GEFS at day 9 keeping the high over us and starting to pull colder air our way

I'm going for this as the way forward, more models perhaps clinging onto this approach in the mid-term as we get nearer New Year's day. Blocked by Atlantic High due West of us and winds backing North to NorthEast (maybe Easterly) by end of the first working week of January.

[Hunt For Cold: Model Discussion - Heading Into Christmas]

45 minutes ago, Penicuikblizzard said:

Certainly going to be very cold in mainland Europe,,but I think it’s going to be one of those winter seasons where the UK is in the middle, no mans land which will result in mild dry weather as we are experiencing just now.

So winds will be stuck coming at us in a sw'rly or westerly flow from now til April? The switch around in our fortunes will arrive during the first week of January. Patience, Grasshopper!

 

Yes, this period of nothingness is quite good for people travelling out and about in fairness, drone attacks aside. It may feel like we're maybe eating up time but the drier it gets underfoot (sun's out here) the chillier the ground, the harsher the frosts eventually become and that's way better for snow events down the road than sodden flooded landscapes.

[Hunt For Cold: Model Discussion - Heading Into Christmas]

29 minutes ago, northwestsnow said:

6Z better now, importing some colder continental air on Boxing day..

lol Feb you posted exactly the same at exactly the same time!

Going back through the Annuls of time, a change to polar type air come Boxing Day is one heck of a repeating trend. So, even having not viewed the outputs people speak of, I'm relying on you good people to update me as I dip in and out of here of late, I reckon a Boxing Day change of pattern has a 75/25 per cent chance of verifying. A mildish Christmas Day on my patch I suspect under ridge conditions and then a front travelling southwards come the 26th would be my bet now. The HP cell I feel will be sitting to the west of the UK at this juncture and hopefully, the flow will be from the North or Northeast

[The hunt for cold - Model discussion (late November)]

11 hours ago, WalsallWeather123 said:

Huge change on ICON in only 6 hours. Thursday will be a nowcasting event. Not one model has a grip on it

 

To be honest, we should expect nothing more, or nothing less when it comes snowcasting. Incidentally, has the forecast not changed again? More focus now on the weekend happenings.

It'll likely be transitional in nature but the cold air is set to stay longer than originally predicted by the NWP suites even just two days ago. By the end of the weekend, it'll be game over and onto looking into the longer-term developments around the Xmas period.

[The hunt for cold - Model discussion (late November)]

One word sums next week up, having just watched the Beeb 10-dayer. 

Whether (or should that read weather), it's the politics or weather for the upcoming week, it is....

UNCERTAINTY 

 

[The hunt for cold - Model discussion (late November)]

6 hours ago, Daniel* said:

Such a laughable difference from UKMO 12z to 00z doesn’t look any good for undercut but nowhere near as progressive to 12z with doomed Scandi block, seemingly a lot of struggle in this area.

Late Wednesday into Thursday is the day of the big battle, 60/40 possibility of some short-lived transient snowfalls around then I'd suggest. The on-the-ground specifics as to who gets it and how much will only be answered as late as Wednesday, as that snow is such an oh-so-tricky thing to forecast, but it's coming to a few of us.

[The hunt for cold - Model discussion (late November)]

11 hours ago, Catacol said:

No charts today from me - but a request for a bit of resilience in this thread over the coming few days. I don't think the ridge next week is going to hold: there isn't the background forcing to sustain it, and it really is just an echo from the final phase of the last pacific wave. Let's not throw the toys out if/when battleground scenarios next week get watered down. It is possible we might have a transient snow event - but to my eye it is really only going to be transient.

It is very clear that torques are reengaging now, and that we are going to see a spike in AAM once again over the coming 1 - 2 weeks. This is going to begin the process of enhancing westerlies at 30N and scrubbing them out at 60N. The jet will drop south in that time span, and the extension of the pacific jet specifically will help reengage a high lat block pattern. Signs of this will begin to appear in NWP modelling in the next few days at the extended range, but it will take until the end of the week until we see NWP pick up on this progression consistently. In the meantime don't mourn the shunting east of the scandy ridge in its upcoming form too much. 

I'm confident of this longer term progression and confident that we will see blocking entrench in the second half of this month driven by the new pacific wave. And this is a pattern that will sustain into January. Great news for all snow lovers. The really interesting bit now is just how the impact of this very favourable pacific pattern will combine with top down impacts from a strat warming event. The Siberian high / Aleutian low Nino combo looks to be a pattern that is going to sustain over the medium term at least - and with such sustained pressure it looks unlikely that the vortex can hold its ground. But will it shatter or just wobble badly? I don't think anyone can be confident of that process yet - all the keen minds in other places are agreed on the magnitude of the hit that is coming - but I've not read a single punter willing to put a bet down on just how this will play out. Pacific forcing will not be overridden by the much weakened vortex in its forecast state - but will the shape of upper winds help reinforce that trop led pattern? If it does then we could be in for a very special period of weather. If it doesn't then cold will still come, but less dramatic in its impacts.

Top post. Thanks, Catacol.

[The hunt for cold - Model discussion (late November)]

13 minutes ago, Summer Sun said:

The ECM mean and op are fairly close through the 10 day run this morning the biggest gap is on the 11th

Decision Day. I'm on a countryside walk, come public house hunt that day, it should be dry on the outside that day, chilly with abundant sunshine. Might be some sleety flakes and hill snow around next week in places as well. The evening runs of the ECM and UKMO are especially important tonight for anyone chasing snowflakes. Deep cold unlikely but chilly to colder than average Temps look like ruling the roost for much of next week. It's all about the D4 and D5 charts from four to five days ago coming to fruition, will it go our way?

[The hunt for cold - Model discussion (late November)]

2 hours ago, Daniel Smith said:

I’m ready to jump down off the fence and hopefully Bluearmy will be joining me!

I’m 60/40 deep cold into the UK next week. High pressure will build this weekend turning things colder, good support for high pressure to extend and build across Scandinavia thereafter. 

Lots to resolve before deep cold touches our shores, but we’re a step closer this evening. Fantastic day 8 GEFS mean. 

 

I'm willing to agree on your comment "High pressure will build this weekend turning things colder, good support for high pressure to extend and build across Scandinavia thereafter." As I mentioned last Monday, there was a growing consensus even then, that between the inter/intra-model runs, the GFS, in particular, wanted to bring in HP dominance around December 6th through to 10th or thereabouts. As for deep cold, we need the ECM D9 and D10 charts showing such scenarios to be there at D4 or D5 in my experience, which means by the end of this working week, we will KNOW whether SNOW is something worth shouting about, for the run-up to the middle of December. Winter proper appears to be lurking close-by.

[The hunt for cold - Model discussion (late November)]

On 26/11/2018 at 19:07, gottolovethisweather said:

Ah, those weekend model suite wobbles strike again and again. The trend is our friend and despite not following the model runs myself, I am happy to go with the consensus that the 2nd week of December is where coldies should be focussing their attention, even if it is purely a dry cool/cold settled spell to kick things off. The 10-day plus forecasts on the BBC news channel which I tend to watch religiously should start picking up on such signals later into the week, with cold weather getting a mention again.

 

I have not been viewing the NWP outputs myself, just relying on you guys but little has changed in my mind from my thoughts this past Monday. A drier, potentially colder than average period of weather could well be heading our way by the end of the next working week. Who knows what week two and the middle of December might offer us? But all eyes on the 10-15 dayers from here on in. Beggars cannot be choosers as my thoughts are well known over the weekend wobbles, but I just hope these charts are still showing some cold/very cold solutions come Monday and Tuesday. Bring on something crisp, sunny and cold please, weather gods, 15 to 16c down South today and tomorrow by Christ!

[The hunt for cold - Model discussion (late November)]

3 minutes ago, Daniel Smith said:

In any case there's fairly good support for temperatures to drop well into single figures by the second week of December

That to me is suggestive not mild Atlantic weather, but either Easterly winds (not deep cold) or a cold PM zonal type pattern. Uncertainties continue going forward towards week 2 of December, mild? Unlikely. But how cold and will it be blocked?

I'm still going for a short period of High-Pressure dominance, akin to UKMO at t+168 if only lasting for a few days. Is there a dry signal backing those charts up as well, come the 2nd week of December?

[The hunt for cold - Model discussion (late November)]

30 minutes ago, blizzard81 said:

Much better output tonight so far. Look at the difference between these two ecm charts for the 1st Dec. The first from Saturday's 12z at t168 and the second from tonight's 12z at t120. A vast improvement there for us coldies going forward. 

Ah, those weekend model suite wobbles strike again and again. The trend is our friend and despite not following the model runs myself, I am happy to go with the consensus that the 2nd week of December is where coldies should be focussing their attention, even if it is purely a dry cool/cold settled spell to kick things off. The 10-day plus forecasts on the BBC news channel which I tend to watch religiously should start picking up on such signals later into the week, with cold weather getting a mention again.

[The hunt for cold - Model discussion (late November)]

1 hour ago, mulzy said:

Let's agree to disagree!

If we can't have cold and snow then sunny and dry is the next best option.  Wet and windy is horrible!!

Particularly so in the heart of Winter, late December through to early February. Oh, the horrific memories of the thirty-nine (yes, it was 39) Atlantic depressions that most of the UK endured from October through to March I think it was, back in 2013/14. Please no, no, never again and I don't even live on the coast. 

That recent winter!

The above reason is precisely why I'm firmly in the traditional cold but crisp or snowy camp and probably always will be, plus the memories of the late 80s and most of the 1990s haunt me too.

 

[The hunt for cold - Model discussion (late November)]

36 minutes ago, jethro said:

All this talk of zonal has got me scared, what I'm after is dry, preferably not windy either. Dear learned people, what are the chances of next Saturday (1st) being a dry, benign day? I'm doing a xmas market, slap bang on top of the Mendips, it's an outdoor event and I could really do without it blowing a hoolie and peeing with rain. Help! Reassure this nervous person please, or at least give me an informed low down so I can adequately prepare if need be.

You want dry, preferably not windy weather, where have you been all year?  As is the want of the British climate, your day will be anything but what you expect I guess, but more hopefully what you want it to be.

[The hunt for cold - Model discussion (late November)]

38 minutes ago, DiagonalRedLine said:

Do feel there’s enough evidence to suggest the Atlantic coming back - the 12Z ECMWF, for me, looks unappealing with Low Pressure racing past the UK like a Great Western Railway train in the dreamland timeframe. But there may still be enough room for the Atlantic to become less of a feature, and/or Low Pressure not breaking through further East at all.

I almost wanted to throw my large toy la-la out of that pram, but think I’ll hold on to it for now. Maybe might be in for a surprise after a little break from the maddening charts.

The next few days the models seem to agree to a continued theme of blocking to our North and Low Pressure to the South, with some further spells of showers or longer spells of rain in the cool Easterly to South-Easterly flow. Mostly for Southern UK areas, although even these areas could see some brighter spells at times. A chance of some frost and mist at night, particularly over Northern areas where the Northern UK High would be more influential.

 

 

It is such an odd pattern right now, so much so I heard a BBC Forecaster, possibly Nick Miller? state how unusual it was, synoptically speaking. So with that in mind, I wouldn't take anything beyond the weekend as set in stone, until say, Friday/Saturday when we might know where the rest of next week is heading. Is Shannon Entrophy at play in the modelling I wonder? Either way, wet snow today in parts of the Isle of Wight even, they can go whole winters without seeing some as well. 

 

[Model output discussion - The Hunt For Cold]

1 hour ago, evans1892 said:

Not quite sure who the original creator of this was but I'm sure business has been booming recently.

Big 12z Ops to come hopefully in the right direction.

Great artistry, that is good @evans1892

[Model output discussion-mid Autumn and beyond]

On 12/11/2018 at 15:15, DiagonalRedLine said:

Yeah, the North-Western Europe area would say seems the favourite place for now for the High Pressure. The models do appear to hint at that. It’s possible that Beast may not be too far away! Guess it will depend for sure how that block behaves. 

And I guess you could say that, lol. Not just an exit from Brexit, but the models would have us believe we’ll be leaving the Atlantic! (At least for the time being ).

And so it proved to be, talk of some sleet and snow showers on the mainstream media next week and not specifically at height or up in prone Northern areas either. A fascinating week ahead for coldies, if nothing overly dramatic, at least it's a start.

[Model output discussion-mid Autumn and beyond]

36 minutes ago, DiagonalRedLine said:

There’s always chances that the Eastern UK block could end up getting knocked away further East as it tries to ridge Northwards from the South-East of the U.K in the next few days, but this seems unlikely. Support for the European block to settle things down for the U.K is high! 

Sorry Atlantic (and your wind and rain), but it looks like you’re gonna lose!

For those areas, such as parts of Wales and some North-Western UK spots that have had particular problems with flooding, it will provide a relieved break! 

1

4

Is this a Brexit exit post? Speaking of the Eastern block and perhaps the best is NorthWest Europe. Beware the release of the Beast, come late November into December? Hopefully, the long-range uncertainty will be sorted by then in the models and in political circles.

[Model output discussion - summer rolls on]

1 hour ago, Frosty. said:

In a nutshell, the Gfs 12z operational shows a north / south split for most of the run, most of the rain and cooler temps further north, the best of the fine weather and warmer temps further south but even the south has a few cooler unsettled days too..but then, as we have seen with recent gfs runs, high pressure becomes dominant towards the end of August and this run, as with the 6z shows a lovely end to summer.☺

 

 

1

Looks very much like a right ole.. then @Frosty.

Mixed Bag

 

[Model output discussion - summer rolls on]

7 hours ago, Scorcher said:

The BBC have just upgraded their temperature forecasts for later in the week- 31C now showing for London on Friday. More like mid 20s for NW England but could go higher as we get closer to the time. Looking good for another hot spell.

Indeed, as before, underdoing Maximums, so at the extreme end, by Friday, I expect we'll see a 32c to 33c around somewhere. After that, might get warmer still. The first ten days of August was always a period to watch, as it was in 2003 and it could be a case of history repeating if not to the same levels, but still something noteworthy.

[Model output discussion - summer rolls on]

On 23/07/2018 at 11:08, gottolovethisweather said:

I agree. The tv forecasts for today showing 32c or perhaps 33c as a maximum temperature and with no let up in the reliable, 34c or 35c will surely be reachable, most likely on Wednesday or Thursday. Short-term upgrades in temperatures are often unforeseen in the NWP outputs for whatever reason, the same goes for extreme minimums in winter to my mind. As for next week and beyond, I'll leave that to the others.

1

Apologies for replying to my own post, but like most coldies rarely do I post in here in Summer. But, yes, the above still applies and far too many in here, stick to the models' temperature forecasts and don't seem to appreciate that they are merely guesses, the reality at t+24, t+72 or t+360 hours is always an unknown. Mid-range temps, say D3 to D6 are often out by two or three degrees, hence Monday's maxes were two days before, predicted to be lower yet 33c was breached. Mine and your gut feeling of past heatwave experiences, climate or even basic weather knowledge and the appreciation of the conditions, here and now, can allow you to make a reasonable judgement. With the Beeb on board with a max temp 34c/35c prediction for Thursday, my attention now turns to the end of July and first ten days of August, I'm thinking the dry Europe heat sink conditions will spread northwards and such maximums will be repeated and potentially exceeded. 36c on the cards in the next 15 days? Watch this space!