[Model Output Discussion - Colder but how cold and for how long?]

7 minutes ago, Kasim Awan said:

Lovely chart to look at, meteociel GFS algorithm looks a bit stingy, 20-25cm widely central areas with 40-50mph gusts. 

Some are adamant of a southwards trend, which I agree is possible. However, the governing factor that is mostly responsible for the latitude of this system is the Azores high. Given we usually see trends northwards in this feature, I wouldn't discount a trend north in this system over time as opposed to a trend south. Very 5050 stuff and we can't bank anything at this point. 

My honest opinion is we’ll see this trend south as I still believe Greenland heights are being underestimated. You can see how it’s 300 miles south from the 12z due to stronger heights but if it does trend south we’ll only get hit by a different system down the line when the jet stream heads north. We can have prolonged cold then heavy battleground or a quicker cold period and heavy snowy battleground. It’s not the worst position to be in for sure!

[Model Output Discussion - Colder but how cold and for how long?]

I don’t know if anyone has covered it or seen it but we have an atmospheric river pointing at the uk for the time this low pressure hits. That usually means unusual amounts and intensity of rain involved with these low pressures.

Hitting arctic air!!! 
 

Gulp!!!

[Model Output Discussion - Colder but how cold and for how long?]

5 minutes ago, Kasim Awan said:

It's a bldy snowstorm that highly active front in very cold air and very little movement over time that chart takes us back to the 1800s.

That chart is biblical in regards to snowstorms I absolutely agree 1881! This event could be insane for someone (if it plays out this way of course as it will head south after without thaw!) Fair play to Tamara this run is very 1979/79 actually!

[Model Output Discussion - Colder but how cold and for how long?]

Just now, MJB said:

Disturbance moving into Scotland

Yep it’s the shortwave that tried to cut off the flow that’s headed in a better direction right for us. Could be a snow maker

[Model Output Discussion - Colder but how cold and for how long?]

2 minutes ago, Met4Cast said:

That low has shifted by a good 200-300 miles and it's much flatter too! Interesting run coming up for sure..

The Icelandic shortwave heading straight through the country fascinating run this one

[Model Output Discussion - Colder but how cold and for how long?]

Just now, Met4Cast said:

Pretty substantial shift south of that low at just day 5!

Substantial over Greenland too upgrading heights at very short notice this…. Could this be the start of some last minute upgrades?

 

[Model Output Discussion - Colder but how cold and for how long?]

@ 102 hours the low has disappeared on the GFS!!!!

[Model Output Discussion - Colder but how cold and for how long?]

7 minutes ago, feb1991blizzard said:

Icelandic high - That would properly bring London to a standstill.

Yummy!! Iceland/Scandi heights are what were discussed with Catacol! I think that would probably be at the extreme end however

[Model Output Discussion - Colder but how cold and for how long?]

14 minutes ago, feb1991blizzard said:

This is what we need to be seeing more of in the output.

Out of interest what is the 500s pattern for that chart buddy as it’s in and around the expected next period of high lat block interest give or take a day or 2 29th.

[Model Output Discussion - Colder but how cold and for how long?]

Just now, suxer said:

Let's get thus one first 

As discussed with @Mike Poole we already have!

[Model Output Discussion - Colder but how cold and for how long?]

Just now, Mike Poole said:

No I can’t say that, because I agree with you that it has indicated the way - but, the last bit - to the shores of the UK - is a leap of faith and always will be!

Exactly! This is as far as we can get to atm with what we know but it’s better than what we had 10years ago. I couldn’t without this science give any sort of mid to long term prediction unless it was 1 week ago. I firmly believe people like Tamara will be at the forefront of weather forecasting 

[Model Output Discussion - Colder but how cold and for how long?]

4 minutes ago, Mike Poole said:

We haven’t nailed the first one yet, Scott!

I think from where we were 3 weeks ago the gdsm has done a bloody good job to get the macro scale correct. 
 

there is a cold period with snow and heights to the north west. This science will never be able to iron out finer details as we get close to an event. 
 

You can’t say that around the 15th or a day or so sooner it hasn’t mapped out a weather pattern that is conducive to cold and snow?

 

If I told you 3 weeks ago the met would be deep diving talking about disruption possible to heavy snow and gave you no scientific reasoning behind it you’d have thought I was bonkers so I think you’ve got to give some credence to the science? 

[Model Output Discussion - Colder but how cold and for how long?]

18 minutes ago, Catacol said:

I think it would be hard to find a better setup than that about to unravel. Only solar is out of ideal kilter but on its own, irrelevant.

-MJO amplified and back in the west pacific in the final third of this month 

- GLAAM has remained high, further surge expected. +EAMT?

- Vortex is weakened and possibly about to split

- Scandy has been cold since the autumn. There is cold nearby to tap into

- eQBO firmly embedded, ENSO Nino with +IOD now done and dusted

These are the keys for me. I’m not moving from what I said a few days ago. Cold for a long time..

I saw the +EAMT that’s imminent! That’s bang on cue and the MJO wave looks significantly more amplified than the last wave which in all fairness we got the crumbs of in phase 1 and not much time in higher impacts phases 7 and 8. 
 

The way I look at it is we’ve just hit a holding pattern that on its own is conducive for high level blocking and cold and about to hit a knock out blow with the next rise in AAM! 

Im with you… cold weather impacts to see out the rest of the winter now with relaxation periods bringing about periods of battleground snow….

Perfect!

Its been fun to muse with you I’ll have one thought of you when we see these Icelandic/scandi rises hopefully on the 29th of January if I’m still in and around the right ball park of lag.

 

29th of January! 
 

Next key date!

[Model Output Discussion - Colder but how cold and for how long?]

Just now, terrier said:

I see the over reaction to one model run from the ECM has begun again. I really do despair at times. Just wait to see where it sits shortly before heading for the nearest viaduct. 

I don’t think this will ever change. I’m just going along with the flow now!

[Model Output Discussion - Colder but how cold and for how long?]

Just now, Hatewarmth said:

Yes it is. BUT can the cold air hold snd push back south to maintain the cover of the 6 inches we would get. Not so sure

The UK is so small and these lows can change so much at this timeframe that not a lot can be said really! We’re looking at the weekend before we’ll even have some kind of idea 

[Model Output Discussion - Colder but how cold and for how long?]

Just now, Eagle Eye said:

CFS suggests rising AAM from a +VE EAMT later into month lagging towards a February response favourable for another round of cold. Second half of Winter = all systems go at the moment compared to first half.

First week of February into the second look more interesting than next week! I just hope we can make the most of this as this has been the best winter pattern in 3 years that I’ve been studying long range GDSM products. Who knows when we’ll next get a combination like this!

[Model Output Discussion - Colder but how cold and for how long?]

Just now, Met4Cast said:

Northern members: It's an amazing run

Southern members: Rubbish run

These types of posts aren't overly helpful and just add confusion. Broadscale patterns for now, wait until high resolution comes into range before worrying about snowfall placements/boundaries. I'm still of the opinion that the low wont even reach the UK, let alone bring snowfall or rain.

I agree with you I think it will be a long way south of where it’s shown!

[Model Output Discussion - Colder but how cold and for how long?]

Just now, booferking said:

It's a step in the wrong direction hopefully outlier in its suit.

It’s going to test this forum next weeks cold 100 miles will make all the difference! Somewhere could have 2 or 3 heavy snow periods in a sweet spot!

[Model Output Discussion - Colder but how cold and for how long?]

Day 7 is an imby chart if I’ve ever seen one! Nail biting if your in the south!

[Model Output Discussion - Colder but how cold and for how long?]

2 minutes ago, Metwatch said:

Those who said the cold is constantly in fantasy land in the moans thread have gone real quiet .

 

Just 96 hours away now and we have a setup like this on all models and ensembles. It really is on its way!

If you check the past 3 days ensembles the cold has upgraded between the 18th and 20th

[Model Output Discussion - Colder but how cold and for how long?]

From Acorns…..

Discussion and musings on the 3rd of January for scandi to take the next lead…

First little signs perhaps of stage 2 of the tropically forced winter atmosphere…. 
 

29th of January for Tamara day perhaps?

[Model Output Discussion - Colder but how cold and for how long?]

3 minutes ago, Mcconnor8 said:

GEM looks beautiful too, even brings snow to the South then a big freeze following it.

what seems is happening is the shortwave near Iceland has delayed the initial plunge of cold air but the heights after this are showing to hold on longer than thought giving a second plunge of cold air. The models are really struggling with the continued levels of flux caused by Decembers rise in momentum and very small climb down to leave us in a state that’s still susceptible to high level blocking. I could not write off a sustained period of cold weather just yet!

The shortwave itself could bring a period of snow however in itself!

[Model Output Discussion - Colder but how cold and for how long?]

2 minutes ago, northwestsnow said:

UKMO 144 - 168

Ukmo is the best run this afternoon of that there is not any doubt. I’d be happy with ECM coming in somewhere near this!

[Model Output Discussion - Colder but how cold and for how long?]

7 minutes ago, Catacol said:

12z runs are verifying better than 00z at the moment, suggesting that amplified solutions are coming up trumps. Fits the GWO orbit.

What do you think to the gwo looking like it’s hardly been touched? 
 

Me personally I’m excited for the next tropical wave and consequent rise in AAM off a good base state! 

[Model Output Discussion - Colder but how cold and for how long?]

25 minutes ago, Kasim Awan said:

This is a thread to objectively analyse model output. I am well aware of the caveats involved, however you really can't cough up a set up more promising for the potential for major snow events.

Agreed mate! As far as snowfall is concerned it’s sensational! It may not have longevity (although background drivers continue to paint a picture that it could or that the rest of winter has longevity) but it has potency!