Winter Model Discussion - The Hunt For Cold - 10th Dec

[Snowstorm1]

Overall pleased with this run but I certainly don't like distant F.I with the PV setting up shop over Greenland!

Still I remain confident that the period between the 19th Dec to Xmas will appear to become far more favourable with regards to snow/cold over the next few days and I continue to disagree with the Met O forecast for this period.

It was mentioned on this morning that Laura Tobin has showed one of her mates on the programme that a white christmas was on the way for those North of the Midlands not on topic which i apologise for but thought it was worth while bit of information

[Methuselah]

Since when were models meant to be anything more than another source of reference? So what, if the ECM was 'incorrect'? So were the GFS, NOGAPS, JMA, BOM, UKMET, CFS (and, no-doubt, all those I've forgotten) and the FAX charts...Even the 500mb anomalies wander away from reality, the further-out they go...

At the end of the day, does it even matter that much? Model-outputs have no effect on the weather at all!

[nick sussex]

Not a bad GFS 06hrs run, this ties in more with my expectations of what to expect from the Russian high.

It can still help by exerting some forcing on troughing near the UK if the upstream pattern turns a bit more favourable, and you get a ne flow.

I don't however see much sign of a sustained easterly, a pressure rise to the nw with sinking trough seems a plausible outcome.

I certainly wouldn't worry about anything past 240hrs, given that the PV may start moving again with perhaps a lobe dropping into Scandi.

There seems to have been alot of talk re the ECM 32 dayer, the same output that was screaming sledges at the ready last week!

Whilst theres decent heights to the north and a more southerly tracking jet you always have a chance.

[mike Meehan]

Well, I'm off to Morocco on Xmas Eve, going by this run. Snow moving out of Spain and into North Africa.... LOL!

Many a true word...........snow over the Atlas Mountains - certainly not an impossibility

[IDO]

Since when were models meant to be anything more than another source of reference? So what, if the ECM was 'incorrect'? So were the GFS, NOGAPS, JMA, BOM, UKMET, CFS (and, no-doubt, all those I've forgotten) and the FAX charts...Even the 500mb anomalies wander away from reality, the further-out they go...

At the end of the day, does it even matter that much? Model-outputs have no effect on the weather at all!

Quite right. They only give us a clue to where the number crunching is going. It doesn't take a lot to make them look stupid.

At the moment they are strongly suggesting medium term zonal hitting Russian Block. They are suggesting the cool/cold zonal will win out but I will not be confident of that for 5-6 days.

Dont shoot the messenger if the ECM ensembles say zonal, that is what they say. IMO all still to play for, though the ENS disagree at this time.

[Harve]

Well, I'm off to Morocco on Xmas Eve, going by this run. Snow moving out of Spain and into North Africa.... LOL!

This doesn't seem too out of the ordinary; the snow is over the Atlas Mountains, where you can ski. Algiers received snow last winter.

[Frosty.]

The models are again hinting at a second bite at the cherry as far as the cold block to the northeast is concerned, the Ecm 00z at T+240 shows low pressure sinking south over the uk which enables colder air from NE Europe to begin to push down across the uk, the Gfs 06z looks even better with a surge of arctic air rushing south across the BI, it looks a lot more potent than the current benign cold snap. In the meantime, both the gfs and ecm show unsettled and gradually less cold weather spreading to all areas towards the end of this week and by saturday the cold uppers are even gone from scotland but it doesn't look mild apart from briefly in southern england but then next week we are controlled by low pressure to the west of the uk, eventually the complex low pushes into the uk and then hopefully will push south as the cold block to the northeast gets another opportunity to bring a cold spell to the uk. The main problems coming up though are more heavy rain and flooding with strong cyclonic winds at times and temps rising closer to the mid december average.

[Waterspout]

This doesn't seem too out of the ordinary; the snow is over the Atlas Mountains, where you can ski. Algiers received snow last winter.

Indeed, but Alicante the day before Will change anyway I suspect!

[AWD]

I will add this in here from Ian Fergusson with regard to the MOGREPS model;

"Looking ahead, broadly unsettled Atlantic domination for nxt fortnight likely, albeit UKMO MOGREPS hints at some temporary E/NE'rly episodes"

Also, courtesy of Matt Hugo;

GFS 2m temp ensembles show a warming up as expected over the weekend and into next week, but then they are shown to cool off again in the longer term.

I will leave the straw for you all to clutch now.

Edited December 11, 2012 by AWD

[Frosty.]

"Looking ahead, broadly unsettled Atlantic domination for nxt fortnight likely, albeit UKMO MOGREPS hints at some temporary E/NE'rly episodes"

That is exactly what the ecm 00z and gfs 06z are showing in the T+240 range onwards, something good for coldies to hope for beyond the upcoming very unsettled and less cold phase.

[Rollo]

TEITS look at the amount if northern blocking it really is magnificent , by t186 we have big mid Atlantic ridge pushing up and linking with Greenland heights , really is fascinating stuff, I don't think we will have to wait all that long to see a Change in our favour. Heights in Greenland fits the bill with the vortex over Siberia.

One wonders how many bites at the cherry will be needed to get our beasterly,way back in the infamous winter of 1947 which did not get going I believe until January 18th,there were I think prior to the onset three failed attempts, I am not saying that will occur but Roger Smith's forecast is promising something like that. I just want some cold and snow now. Edited December 11, 2012 by Rollo

[Iceaxecrampon]

Since when were models meant to be anything more than another source of reference? So what, if the ECM was 'incorrect'? So were the GFS, NOGAPS, JMA, BOM, UKMET, CFS (and, no-doubt, all those I've forgotten) and the FAX charts...Even the 500mb anomalies wander away from reality, the further-out they go...

At the end of the day, does it even matter that much? Model-outputs have no effect on the weather at all!

From a Netweather revenue point of view I think models - and watching them - do matter....!

Ian

If only the bandwidth cost didn't munch any revenue :-) if the pictures were smaller, or maybe replaced with words - cold, colder, not cold, bin me, etc we'd be laughing.

Edited December 11, 2012 by IanM

[Davey80]

Where can I see Roger's forecast please?

[Dean E]

I think the word 'zonal' should be a banned word for this winter... Nothing zonal is coming our way.

A blocked pattern to our North and east and an Azores high is present, blocking that low and sending it nowhere but spinning around the North Atlantic... Strange setup for this time of the year.

With a blocked practically all around us and a low spinning around, rainfall amounts do look very very concerning.

I believe this setup is temporary but only a few days of rain is enough to do damage.

SM

[polarlow2]

I'm not sure if this is the right place to ask, if it is not then mods, feel free to move. With winters like '63 and '47, if models had existed back then do you think they would have known something 'was up' at this stage? I often read about background signals and the like, but can you tell what's around the corner?

[Methuselah]

I'm not sure if this is the right place to ask, if it is not then mods, feel free to move. With winters like '63 and '47, if models had existed back then do you think they would have known something 'was up' at this stage? I often read about background signals and the like, but can you tell what's around the corner?

You can find the charts for both those winters in the Chart Archives: http://www.wetterzentrale.de/archive/ra/1962/Rrea00119621211.gif

[nick sussex]

I will add this in here from Ian Fergusson with regard to the MOGREPS model;

"Looking ahead, broadly unsettled Atlantic domination for nxt fortnight likely, albeit UKMO MOGREPS hints at some temporary E/NE'rly episodes"

Also, courtesy of Matt Hugo;

GFS 2m temp ensembles show a warming up as expected over the weekend and into next week, but then they are shown to cool off again in the longer term.

I will leave the straw for you all to clutch now.

Lol! Yes those ensembles look okay, and this certainly isn't a typical zonal mildfest with PV over Greenland and jet angled sw/ne.

If it was that clear cut re alleged zonal you wouldn't have a hope of even an e or ne flow. If you keep a southerly tracking jet, decent heights to the north and the block to the east located far enough north then there is a chance you can get some colder shots.

We'll see, best to not get too optimistic given the last week!

Looking at the upstream pattern in the USA low pressure is likely to take a more southerly track across there as high pressure builds around Hudson Bay.

This comment from NOAA from a European perspective is a positive:

THE GFS/GEFS MEAN ARE STILL A BIT

QUICKER THAN THE ECMWF/12Z ECWMF ENSEMBLE MEAN... AS CAN BE

TYPICAL. WHILE THE TREND FOR THE PAST SEVERAL DAYS HAS BEEN

QUICKER RATHER THAN SLOWER... THE INCREASED BLOCKING OVER HUDSON

BAY MAY ACT TO SLOW THE PROGRESSION OF SYSTEMS THROUGH THE

SOUTHERN CONUS BY EARLY NEXT WEEK.

Edited December 11, 2012 by nick sussex

[AWD]

GFS 06z Ensembles also show a cooling trend after this weeks warm up;

http://www.wetterzentrale.de/pics/MT8_Manchester_ens.png

If we could knock out some of those mild members in FI then the mean would probably go sub zero again in FI.

Anyway, off to the regionals I go now. Ice days being reported IMBY.

[Frosty.]

Well we may not have to wait long for our next cold snap/spell, after the current benign cold snap is ended later this week, we look locked into an atlantic dominated spell with winds mainly originating in the north atlantic so it won't be mild, probably average at best and sometimes slightly below but with spells of wet and windy weather seperated by sunshine and showers, not much sign of high pressure in that period apart from maybe some brief ridging but our hopes then rest on whether low pressure over the uk can sink south in the run up to christmas and allow the persistent cold block to the northeast another shot at the uk, hopefully a more potent shot than the current one with a stronger flow of arctic or continental arctic air to gain a foothold. But it does currently look like we are going to have at least a week of less cold and very unsettled weather with renewed flooding.

Edited December 11, 2012 by Frosty039

[Summer Sun]

The ensembles continue to look positive for another cool down after this mild blip? later this week and early next week

Lots of members trending cold now just before Christmas and beyond a white Christmas anyone?

Edited December 11, 2012 by Gavin.

[Snowman.]

I think the word 'zonal' should be a banned word for this winter... Nothing zonal is coming our way.

A blocked pattern to our North and east and an Azores high is present, blocking that low and sending it nowhere but spinning around the North Atlantic... Strange setup for this time of the year.

With a blocked practically all around us and a low spinning around, rainfall amounts do look very very concerning.

I believe this setup is temporary but only a few days of rain is enough to do damage.

SM

I also believe this when I hear "Atlantic dominated" I would normally expect low after low after low not low spinning around for a few days before backing west.

[snowking]

Any hopes of colder incursions (as mentioned above by Frosty, and suggested by Ian Fergussons tweet earlier re: MOGREPS) are really now reliant of the balance of energy being modelled across the Atlantic and towards Greenland.

Any relenting and we see this:

Which cuts off the mean trough, and forces any remaining energy to dive SE - though heights still rather too high through Iberia for anything prolonged.

However, even there we can see a huge LP ready to smash through the fairly weak ridge off the eastern seaboard.

It's still all down to the transfer of energy towards NE Siberia, and modelling is likely to struggle with this for some days yet (as evidenced by the large spread in ensembles). We're not looking at anything substantial, I would suggest, until into the new year now, however that period 20-25 dec is the one to look at in the search for cold

SK

[kold weather]

Hmmm on the face of it not great models, but I will take a very large positive from the fact that whilst it is atlantic dominated, notice where the upper troughs are sitting, around our latitude by in large..

Thats far removed from the zonal fest of yesteryear when you have 930-950mbs lows wizzing between Iceland and Greenland. It clearly would only take that big warming in the stratosphere from the GFs in the outer ranges (which has been inching closer) to really finish the PV, which is trying to rebound but not doing a great job (its jsut a shame the atlantic has thrown us a wench of a pattern!)

[Man With Beard]

GFS 06z Ensembles also show a cooling trend after this weeks warm up;

http://www.wetterzentrale.de/pics/MT8_Manchester_ens.png

If we could knock out some of those mild members in FI then the mean would probably go sub zero again in FI.

Anyway, off to the regionals I go now. Ice days being reported IMBY.

Virtually all the runs get to -5C (850's) towards the end. Suggesting that our Atlantic low will not get stuck in situ for weeks on end - winter gets another chance from mid next mid-week onwards perhaps. (Oh, and I see a few nowcasts creeping up at T24 / T48 ... latest indicators suggest it may well be more than just rain )

[Frosty.]

I just hope that if we do get another opportunity of cold weather after next week that it will last over christmas, not like the 6z which almost gets there before the pattern becomes flatter, but at least the 6z FI cold looks better than the current lame effort, yes it's cold with some fog around in the next few nights but compared to what it could have been, it's lame, no wonder the mood in here is so flat.