Model Output Discussion 01/09/17

[karlos1983]

3 minutes ago, shaky said:

Hi nick could you post the 168 hour ukmo chart if possible!!thanks!!

Screams undercut to me

Edited November 25, 2017 by karlos1983

[Ice Day]

5 minutes ago, karlos1983 said:

Hello PV lobe, welcome to the neighbourhood put your feet up, get comfortable and unleash your fury on our little island will you 

 

Of course it's just for fun at that range, but *IF* it did pan out like that we would be right in the bullseye.  Lovely lovely stuff, almost makes Christmas shopping today bearable!

[nick sussex]

Its always a good sign if the models want to retrogress a high over the UK.

You can think of it as a bellwether which signifies a lengthier spell of cold. All decent cold spells include retrogression because its very hard to sustain cold without that.

In those situations you get a rinse and repeat scenario alternating between easterly and northerly, that's what happened in December 2010.

I'm not for one moment suggesting another Dec 2010 is on the cards! That was a historic event and theres a reason its so rare.

[phil nw.]

Heading into December and to see modelling showing the polar vortex being pushed around like this is quite unusual at this time of year.

Quite an un Nina like pattern where by now we usually see a N.Pacific/Alaskan ridge.Instead we have an ongoing trend for further Atlantic and indeed Russian ridging.

ECM mean T240hrs.

 

The latest ECM data suggests zonal winds dropping off again where normally they would be on the uptick.

all signs of a weaker and therefore buckling jet.

The UKMO certainly full on with this cold northerly next week as are the others.

A look at the latest fax and 850's for Tuesday 

showing a re-load of Arctic air after the less cold westerly from Monday.Notice the minor trough line over Scotland coming south which could well bring quite a bit of snowfall up there.

Interesting times.

 

[The Northern Ramper]

Forget all this autumn chat,Larry confirming below that winter has arrived in Saddleworth ?

And looking at the models, it could arrive anywhere on Thursday. ?

Larry is a coldie btw

Edited November 25, 2017 by Ramp

[nick sussex]

26 minutes ago, shaky said:

Hi nick could you post the 168 hour ukmo chart if possible!!thanks!!

I see Karlos has posted that.  Heres the link for you to bookmark:

https://ruc.noaa.gov/hfip/tcgen/

There was always mystery surrounding the UKMO because Fergie posted they did go to T168hrs but we never had public access to it before.

Its a shame we don't get the full European and NH views but todays T168hrs is excellent and people in here know I'm hard to please!

[Methuselah]

3 minutes ago, phil nw. said:

Heading into December and to see modelling showing the polar vortex being pushed around like this is quite unusual at this time of year.

Quite an un Nina like pattern where by now we usually see a N.Pacific/Alaskan ridge.Instead we have an ongoing trend for further Atlantic and indeed Russian ridging.

ECM mean T240hrs.

 

The latest ECM data suggests zonal winds dropping off again where normally they would be on the uptick.

all signs of a weaker and therefore buckling jet.

The UKMO certainly full on with this cold northerly next week as are the others.

A look at the latest fax and 850's for Tuesday 

showing a re-load of Arctic air after the less cold westerly from Monday.Notice the minor trough line over Scotland coming south which could well bring quite a bit of snowfall up there.

Interesting times.

 

Given a wee bit of luck, we might even be in for some of the white stuff all the way down here!

[Duane S.]

Weirdly my Facebook has just flashed up a 'memory' from something I posted on there 5 years ago (although, posted on the 21st, not 5 years to the day). I don't remember it but it looks like early winter 2012 our hopes were up then as well? Nice chart though... (didn't occur of course)

Compare to now (and in the much closer timeframe)...

Ah! I've just clicked! That was of course the 'That ECM' early winter!?Mind you, it certainly turned out to be a fairly memorable winter in the end though ?

 

Edited November 25, 2017 by s4lancia

[karlos1983]

Mean doesn’t get above 5c 2m Temp all the way out to D15, 

Now...these are obviously  useless and shouldn’t take up the storage space they use..... but I like them 

Edited November 25, 2017 by karlos1983
Typo

[Snowy Hibbo]

Everyone seems excited about the UKMO's nice Atlantic ridge.

Just looking closer to the UK.

Interesting difference between the path of the low coming over the UK on Monday, between UKMO and GFS.

UKMO shows the low going straight over the UK...

And GFS shows the low heading north of the UK. 

Both models agree on the stalling around Scandinavia, but they don't seem to agree on how the low crosses the U.K. This could mean quite a lot on the mesoscale side, with rain and snow accum over the UK.

CMC shows the low going over Scotland and heading SE down to Germany, rather than over to Scandinavia.

The positioning of when the low hits the UK is important, but also the positioning of the low when it slows down, and sends northerlies over the UK(and colder air) is also crucial. So I would be definitely be important to watch that low IMO to work out how that cold air is going to be directed across the UK and whether there could be widespread low level snow....

Edited November 25, 2017 by Snowy Hibbo

[tight isobar]

3 minutes ago, Snowy Hibbo said:

Everyone seems excited about the longer term outlook, with the UKMO's nice Atlantic ridge.

Just looking in the shorter term....

Interesting difference between the path of the low coming over the UK on Monday, between UKMO and GFS.

UKMO shows the low going straight over the UK...

And GFS shows the low heading north of the UK. 

Both models agree on the stalling around Scandinavia, but they don't seem to agree on how the low crosses the U.K. This could mean quite a lot on the mesoscale side, with rain and snow accum over the UK.

CMC shows the low going over Scotland and heading SE down to Germany, rather than over to Scandinavia.

The positioning of when the low hits the UK is important, but also the positioning of the low when it slows down, and sends northerlies over the UK(and colder air) is also crucial. So I would be definitely be important to watch that low IMO....

Yeah' that feature is a BIG player...medium-range!

[Duane S.]

Nice UKMO day 7 chart! In fact, another encouraging set of model runs this morning.

Most of us here are guilty of hopecasting to one degree or another, based on a mixture of bias confirmation and the fact the vast majority of us are cold (and of course snow) lovers. If the glove doesn't quite fit, i.e. the chart outputs aren't matching that of a flat /poorly oriented/ powered-up jet, we tend to shrug it aside in favour of the far less probable 'long shot' ?

This however, is not one of those occasions. It probably only happens on average maybe once a year, but the dice are definitely loaded in our favour. It could be better of course, it's not perfect but then I'm sure there hasn't been a run up to a cold period where that hasn't been the case.

This is the time of year the vortex should be gathering its family of daughter vortices from their autumn meanderings, ready to dominate proceedings through December from the Greenland /Pole locale. This is not (yet) occurring and we have a potential feedback situation here (where one wave drives the next and the jet keeps buckling) which, crucially, in tandem with a decent E-QBO, could preclude the vortex from getting the upper hand for the foreseeable future. 

Like Nick said above, I am certainly not predicting another December 2010, just pointing out the genuine potential from this current set up. Potential doesn't equate to snow but snow doesn't appear without there having been potential...

[northwestsnow]

Yes gfs brings the temps down nicely next week- a few snaphots of towns and cities,will be lower rural areas-

and finally a little shot of higher parts of Oldham (next to pennines) this morning

[Summer Sun]

06z Op is on the warm side of the mean throughout from December 3rd with the exception of the 8th and the very end

Edited November 25, 2017 by Summer Sun

[northwestsnow]

Just now, Summer Sun said:

06z Op is on the warm side of the mean throughout from December 3rd with the exception of the 8th

Great set of ens- mainly dry and cold air coming down from the north in late Nov/early Dec = low minima

[karlos1983]

Another run & Canadian warming still showing, this time a bit more pronounced and it begins earlier in the run.

it seems at the moment we are crossing t’s and dotting the i’s. 

Edited November 25, 2017 by karlos1983

[feb1991blizzard]

2 minutes ago, karlos1983 said:

Another run & Canadian warming still showing, this time a bit more pronounced and it begins earlier in the run.

it seems at the moment we are crossing t’s and dotting the i’s. 

Everyone is quoting a Canadian warming happening in FI GFS lately, may I ask how that is a Canadian warming when its nowhere near Canada, to me that looks like a regulation strat warming event coming 'round the back' of the Eurasian sector as most warming's do.

[JBMWeatherForever]

One great set of charts followed by another at the moment. I know some have been saying that the depth of cold to our north east in not the same as 2010, but by the end of next week that may well have changed, and we could be on the cusp of something special ! Cold does have to be given time to build.  Exciting times I think !  

[northwestsnow]

5 minutes ago, feb1991blizzard said:

Everyone is quoting a Canadian warming happening in FI GFS lately, may I ask how that is a Canadian warming when its nowhere near Canada, to me that looks like a regulation strat warming event coming 'round the back' of the Eurasian sector as most warming's do.

Agreed- doesn't look like a canadian warming- that said, i don't think that chart posted would do any harm at all (if it verified).

[tight isobar]

10 minutes ago, feb1991blizzard said:

Everyone is quoting a Canadian warming happening in FI GFS lately, may I ask how that is a Canadian warming when its nowhere near Canada, to me that looks like a regulation strat warming event coming 'round the back' of the Eurasian sector as most warming's do.

Its sub-Asian warm...

not canadian!

Edited November 25, 2017 by tight isobar

[ArHu3]

15 minutes ago, karlos1983 said:

Another run & Canadian warming still showing, this time a bit more pronounced and it begins earlier in the run.

it seems at the moment we are crossing t’s and dotting the i’s. 

Last year gfs teased us almost all winter with one of these but it stayed forever past 192h or do, only to finally materialize mid February. I'll believe it when it is modeled around 168h

[feb1991blizzard]

3 minutes ago, northwestsnow said:

Agreed- doesn't look like a canadian warming- that said, i don't think that chart posted would do any harm at all (if it verified).

If it carries on yes, and by then it would also include Canada but so would any warming if it ended up a major warming.

Either way, yes, it would only do good I would suggest.

[karlos1983]

23 minutes ago, feb1991blizzard said:

Everyone is quoting a Canadian warming happening in FI GFS lately, may I ask how that is a Canadian warming when its nowhere near Canada, to me that looks like a regulation strat warming event coming 'round the back' of the Eurasian sector as most warming's do.

Okay... not yet it isn’t but, it’s headed that way surely?

I’m far from knowledgeable when it comes to the strat, but it looks to me the warming is heading to Canada? (I don’t even know if that’s possible) I’m happy to be told otherwise and learn in a constructive manner!

Edited November 25, 2017 by karlos1983
Last line removed

[feb1991blizzard]

17 minutes ago, karlos1983 said:

Okay... not yet it isn’t but, it’s headed that way surely?

I’m far from knowledgeable when it comes to the strat, but it looks to me the warming is heading to Canada? (I don’t even know if that’s possible) I’m happy to be told otherwise and learn in a constructive manner. 

Yes - and me, that's why a queried it, it does look nearer to the pole as it starts which means it could end affecting Canada that slight bit more but looks very similar to most warmings.

 

EDIT : possibly stand corrected though, just looked that the 1962 one started very similar to this one and.

 

 

Edited November 25, 2017 by feb1991blizzard

[SMU]

I cant paste it in here- but a post worth a read if you want to know why the strats about to crash in the winter thoughts thread...

S

PS this is different to 1962 as that was a displacement event-

Edited November 25, 2017 by Steve Murr