Winter Model Discussion - Cold Hunting 08/01/13 00z Onwards

[Mountain Snow]

I couldn't draw a better chart.

http://www.wetterzen...s/Rtavn2521.png

That is as good as it can possibly get for the UK. This would cripple the UK and would make the Dec 2009, 2010 cold spells look pathetic with regards to snowfall amounts!

Model learner here, could someone please explain what makes this chart so amazing? To my untrained eye all I see is a slack NE flow with snow showers for Eastern coasts. Or am I completely miss-reading it?! Ta

[Stu_London]

I made a prediction back in November that the End of Jan and up to the Middle of Feb was going to be cold..How cold of course I could not tell..But one thing I would like an answer or view on is why is Russia warming up? A huge scatter I know but still..Some very warm runs there..

the relatively milder runs are associated with lower than normal SLP in that area than you would expect from an attack from the NE.

Normally in these situations an arctic high drops down into Northern Russia and very cold uppers move clockwise along it's flank.

[Summer Sun]

A strong block to the north here

Which leads to this

Interesting times ahead, either GFS is leading us down the garden path or other models will follow suite

Snowfall charts for 3 to 6 days upto and including Monday 14th

Edited January 8, 2013 by Gavin.

[BLAST FROM THE PAST]

I think it's becoming clear that the first (weak) bubble of high pressure over Scandinavia is of no worth to us - it all boils down to whether we can get a second inflation of heights, this time over Greenland, and more substantial.

No the bubble of HP that builds to our NE is actually a major piece of the puzzle. Its that that stops the Atlantic in its tracks and starts the ball rolling. Without it we'd have a SW/NE express trainBFTP

[bluearmy]

Best set of gefs so far - from what i've seen thus far

[SE Blizzards]

Well, if the control is anything to go by all of the UK shut down, Snow, Freezing temps, chaos etc etc!!

http://www.meteociel...&mode=0&carte=1

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=192&code=0&mode=1&carte=1

Edited January 8, 2013 by SE Blizzards

[AWD]

Think the GFS Op could do with a little more support;

Chilly outlook though;

[mcweather]

Think the GFS Op could do with a little more support;

Chilly outlook though;

has some support from the control though so enough to be going on with

[Southender]

Well as expected the Op is a massive outlier in the mid to latter range. The control does follow it to an extent though. Plenty of support for sub -5c 850's at day 6 though which is encouraging.

Edited January 8, 2013 by Shrimper

[Troubleatmill]

Model learner here, could someone please explain what makes this chart so amazing? To my untrained eye all I see is a slack NE flow with snow showers for Eastern coasts. Or am I completely miss-reading it?! Ta

I do agree, its amazing chart for cold and snow showers or streamers into the east but do believe 2010 brought widespread snow....heck even i got some from a brief northwest incursion during it,

Saying that it is still an amazing chart and would take it anyday for pure cold lol! for me last nights 18z was the perfect winter chart for all, but hey its saying something about the outputs at the moment if we are even talking like this haha!!

And you are lucky where you are good buddy, i was up Catstye Cam a few weeks back and up to my knees in fresh powder snow

Edited January 8, 2013 by Nick JB

[ITSY]

Still, regardless of details, 13/14 ens members and the op and control (so 16 of 22 GFS runs) either ridge substantial heights into or create a block over Greenland.

[NorthernRab]

Well as expected the Op is a massive outlier in the mid to latter range. The control does follow it to an extent though.

It's not a massive outlier, it has some support. The term outlier is thrown about far too readily these days.

[Backtrack]

It's not a massive outlier, it has some support. The term outlier is thrown about far too readily these days.

In the terms of how many ensemble runs follow the OP, I would class it as an outlier in the mid-term. Perhaps not so much in the late term though, but this is really to be expected.

[Weathizard]

Lots more mild options compared to last night though, noticed an increase recently something that needs to be watched, just to add some balance I know the control backs the OP but we've seen this already this winter and its gone wrong. The mean is also significantly higher than last night.

Not getting too far ahead of myself.

[Summer Sun]

06z ensembles

A few more mild members there compared to yesterday

[mcweather]

Lots more mild options compared to last night though, noticed an increase recently something that needs to be watched, just to add some balance I know the control backs the OP but we've seen this already this winter and its gone wrong. The mean is also significantly higher than last night.

Not getting too far ahead of myself.

but as Itsy quite righty points out

'Still, regardless of details, 13/14 ens members and the op and control (so 16 of 22 GFS runs) either ridge substantial heights into or create a block over Greenland'

[mountain shadow]

Regardless of what any output is showing until i see it on an ECM operational run im not believing.

The last two operational runs from the best model is not supportive of big Greenland heights.

Lets not get ahead of ourselves......yet.

[fergieweather]

In summary, UKMO latest goes for brief block; mostly dry & cold next week, followed into 10-15d period by increasing mobility with some rain-snow events from W, with heavy rain becoming more prevalent in SW as Atlantic comes more to the fore. However - and this is CRITICAL point - they stress Shannon entropy has now broken all previous records!! GFS solutions not mentioned in any analysis. Take from that they're leaning to EC but I do stress they acknowledge high state of model volatility, so it's a real poison chalice to be tasked with preparing any outlook summary so far ahead. Thus, major health warning on potential outcomes.

[NorthernRab]

In the terms of how many ensemble runs follow the OP, I would class it as an outlier in the mid-term. Perhaps not so much in the late term though, but this is really to be expected.

Tenuous though and certainly not "massive". It has support in the medium term and doesn't show anything outlandish in relation to the other outcomes. True outliers have no support and tend to be more error-related, but not the time or place I guess.

[Southender]

Hmmm, latest METO outlook not exactly brilliant. Seems they are leaning towards the Atlantic encroaching a bit further than the likes of the GFS suggest.

EDIT: Just seen Ian F's post. Massive uncertainty still. But perhaps the GFS is barking up the wrong tree at present.

Edited January 8, 2013 by Shrimper

[Bobby]

GEM gives a cracking snow event for the south on Saturday, if that comes off as shown there could be a foot of snow for some. Please be true!

Looking further ahead, the ECM is the King of models and is rarely wrong at +144 where it starts to go pear-shaped, especially twice in a row which is worrying, and combined with the fact the GFS OP has been an outlier I am inclined to back something closer to the ECM and the GFS at the moment, however a lot of uncertainty so best not to pay much attention beyond.

But that GEM, shows that people are chasing rainbows in FI when something very interesting could just be around the corner. Though I suppose even the weekend is near-FI at the moment but nice to have something interesting that's not two weeks away to discuss.

Edited January 8, 2013 by Bobby

[UV-RAY]

In summary, UKMO latest goes for brief block; mostly dry & cold next week, followed into 10-15d period by increasing mobility with some rain-snow events from W, with heavy rain becoming more prevalent in SW as Atlantic comes more to the fore. However - and this is CRITICAL point - they stress Shannon entropy has now broken all previous records!! GFS solutions not mentioned in any analysis. Take from that they're leaning to EC but I do stress they acknowledge high state of model volatility, so it's a real poison chalice to be tasked with preparing any outlook summary so far ahead. Thus, major health warning on potential outcomes.

It's not what many members on here wanted to hear Ian, but I think it's a good call given the current outlook. It's a case of more runs needed before we know the medium term outlook let alone the longer term. Edited January 8, 2013 by Sceptical Inquirer

[ITSY]

In summary, UKMO latest goes for brief block; mostly dry & cold next week, followed into 10-15d period by increasing mobility with some rain-snow events from W, with heavy rain becoming more prevalent in SW as Atlantic comes more to the fore. However - and this is CRITICAL point - they stress Shannon entropy has now broken all previous records!! GFS solutions not mentioned in any analysis. Take from that they're leaning to EC but I do stress they acknowledge high state of model volatility, so it's a real poison chalice to be tasked with preparing any outlook summary so far ahead. Thus, major health warning on potential outcomes.

Seems to tie in with the greater number of milder runs in the 06 pack this morning.

[bradymk]

In summary, UKMO latest goes for brief block; mostly dry & cold next week, followed into 10-15d period by increasing mobility with some rain-snow events from W, with heavy rain becoming more prevalent in SW as Atlantic comes more to the fore. However - and this is CRITICAL point - they stress Shannon entropy has now broken all previous records!! GFS solutions not mentioned in any analysis. Take from that they're leaning to EC but I do stress they acknowledge high state of model volatility, so it's a real poison chalice to be tasked with preparing any outlook summary so far ahead. Thus, major health warning on potential outcomes.

Thanks Ian, any info on the potential for v cold weather once effects of SSW are more apparent towards final third of month?

[Weathizard]

In summary, UKMO latest goes for brief block; mostly dry & cold next week, followed into 10-15d period by increasing mobility with some rain-snow events from W, with heavy rain becoming more prevalent in SW as Atlantic comes more to the fore. However - and this is CRITICAL point - they stress Shannon entropy has now broken all previous records!! GFS solutions not mentioned in any analysis. Take from that they're leaning to EC but I do stress they acknowledge high state of model volatility, so it's a real poison chalice to be tasked with preparing any outlook summary so far ahead. Thus, major health warning on potential outcomes.

So backing the ECM really really? I was expecting that to be fair as the MET normally back the ECM as it is the most reliable model, as 2 days ago they were backing it when it was showing some crazy sypnotics. Feel sorry for them really at the moment though as its truly impossible for anyone, even chief forecasters who have been doing it for years have no idea where its going to go, very much on a knife edge. GFS 06z shows the evolution that we all want, practically the whole run with -5 or lower uppers BUT as you say right now, although the GFS has been consistent last 3 runs, I'd back the ECM over the GFS just on the fact that more mild members are appearing in FI and gut feeling. Saying that, even if the Atlantic does come back for a brief time, battleground snow is possible and plenty more opportunities with the SSW effects.