Model Output Discussion - cold spell to end Autumn

[bluearmy]

1 minute ago, blizzard81 said:

I do hope you are right and my fears are unfounded. I am talking about something in the more reliable range though. Amplification in the Atlantic is still shown to be around 10 days away and we all know how things can change rapidly between now and then. 

It is ??

given the clustering on eps which is clear from the spreads I wouldn’t say any solution would be currently favoured - one of the clusters looks much more gfs btw ......

[Daniel*]

15 minutes ago, blizzard81 said:

I do hope you are right and my fears are unfounded. I am talking about something in the more reliable range though. Amplification in the Atlantic is still shown to be around 10 days away and we all know how things can change rapidly between now and then. 

Jesus wept.

It’s in the reliable timeframe the amplification in the Atlantic is what secures us our very cold and wintry NNW/N’ly.

How we go on from here is rather uncertain IMO it will turn less cold briefly..

[feb1991blizzard]

Anyone else feeling the possibilities of an Easterly based on the EPS deep in FI and also the GEFS / GFS?

[Chesil View]

Just now, feb1991blizzard said:

Anyone else feeling the possibilities of an Easterly based on the EPS deep in FI and also the GEFS / GFS?

Yes feb Myeslf and a few others have neen dropping hints for a few days now.

[blizzard81]

8 minutes ago, Daniel* said:

Jesus wept.

It’s in the reliable timeframe the amplification in the Atlantic is what secures us our very cold and wintry NNW/N’ly.

How we go on from here is rather uncertain IMO it will turn less cold briefly..

I was referring to events post this northerly. 

[Man With Beard]

29 minutes ago, karlos1983 said:

UKMO 168 

hard to say with that view, but looks a lack of ridging in the Atlantic 

Used this phrase a lot recently but "knife-edge". Is this front now going to slide in a SE direction?? We can't see.

[nick sussex]

Not much change overnight. Still the same overall pattern for at least the next ten days, its just filling in the detail which is difficult and of course all important re the possible slider low around T168hrs.

In terms of the UKMO which once again has become the attention seeker for the wrong reasons I'd say at this point its a clear outlier.

Regardless of the differences downstream between the ECM and GFS they both keep more amplification in the east Pacific which is also supported by the GEM  at T144hrs, the UKMO has the flattest solution over the west USA and Canada. Aswell as this given comments from NOAA in terms of where the Atlantic ridge is expected to be this throws further doubt into its placement of the ridge.

TROUGHING WILL BE STUCK IN THE EAST AS UPPER RIDGING REMAINS IN
PLACE OVER WESTERN CANADA/CONUS AS WELL AS IN THE NW ATLANTIC.

Even with it being flatter at T144hrs looking further upstream it still looks like it will re-load the positive PNA pattern. And its T168hrs chart still has the jet to the south of the UK.

So just as the other day not the best from it but certainly people shouldn't view its output as bringing the curtain down on cold prospects.

In terms of the slider low still lots of uncertainty there but whatever happens although the outputs don't shout bitter cold and ice days the re-loading positive PNA keeps cold and snow options on the table until at least the middle of the month.

[Methuselah]

Taking things at face value it looks as if, post the coming weekend's potential wintryness, the much talked about pseudo-secondary slider shortwave might not deliver the goods, after all?

Having said that, my impression is that winter is far from over...one isolated failure does not maketh a winter-long blow torch....

[Daniel*]

2 minutes ago, Man With Beard said:

Used this phrase a lot recently but "knife-edge". Is this front now going to slide in a SE direction?? We can't see.

Someone been excessively reading the netweather winter forecast?

I’m not quite sure what to make of the UKMO if we had a wider view that would be most helpful looks like it has a slight negative tilt so I suspect it will. 

[Chesil View]

Just now, Ed Stone said:

Taking things at face value it looks as if, post the coming weekend's potential wintryness, the much talked about pseudo-secondary slider shortwave might not deliver the goods, after all?

Having said that, my impression is that winter is far from over...one isolated failure does not maketh a winter-long blow torch....

quote of the morning

[Frosty.]

I needed something to take my mind off the spineless, gutless useless England cricket team in Australia and I have to say, the Gfs 00z has helped a lot!..it's set to turn arctic after the wet and windy midweek period and some of us will see snow!

[knocker]

48 minutes ago, Daniel* said:

Someone been excessively reading the netweather winter forecast?

I’m not quite sure what to make of the UKMO if we had a wider view that would be most helpful looks like it has a slight negative tilt so I suspect it will. 

To me, with the trough down the Irish Sea, it looks similar to the ecm but about 12-18 hours behind in the evolution but I must admit to not being a great lover of the T168 chart

[Nick F]

Mesoscale picture somewhat uncertain beyond T+120 wrt the slider low track late weekend, perhaps in between the GFS and EC maybe the best guidance unless the GFS takes a big deviation north with the low, which is possible given that it has been tending to trend too far south with the jet recently. A look at the 00z EC standard deviation of high res MSLP to the spread of the ens suggests an increased level of uncertainty to the NW near Greenland next weekend where the slider low originates:

But the bigger picture is still looking good for episodes of cold or cold to continue as we head to mid-month. The 7-12 (5) day EPS mean indicates the Euro trough still entrenched and mean ridge toward Iceland to the west. Also that +PNA ridge continuing to warm the arctic at the H5 level. So even though there’s uncertainty in the mesoscale, such as slider low track late weekend, there does look to be propensity for ridging to return to our west and NW.

 

Edited December 4, 2017 by Nick F

[Justin Miller]

Hidden

So the question is, we seem to have N/N’Wly flow from Friday for at least 4 days, but I saw earlier this week the GFS hinted at some back edge snow on the low this Thursday, is this still a possibility, I hope so as it would be better for us here in London region, as N’wly Flows never bring us anything. Also saw that there is the possibility of some undercutting channel lows.

[Tracy Flick]

1 hour ago, karlos1983 said:

UKMO 168 

hard to say with that view, but looks a lack of ridging in the Atlantic 

I think every time someone posts these day 7 charts it should be accompanied by 'hard to say with this view...'

Beyond Caribbean tropical storm stuff I can't see who or what it is supposed to be produced for.

[Frosty.]

Just watch this guys..it has a happy ending!

Darn it, doesn't work..in a nutshell it showed an arctic blast later this week!

2nd time lucky

 

Edited December 4, 2017 by Frosty.

[warrenb]

2 minutes ago, Frosty. said:

Just watch this guys..it has a happy ending!

aLojY7ZffDiCZxR2.jpg_small

Doesn't work

[karlos1983]

4 minutes ago, meh said:

I think every time someone posts these day 7 charts it should be accompanied by 'hard to say with this view...'

Beyond Caribbean tropical storm stuff I can't see who or what it is supposed to be produced for.

that's exactly what i said? 

-6 850's clearing the south coast by Friday morning and a stiff biting breeze

[andymusic]

will the slider be hit or miss this time?

[weirpig]

whilst everyone seems to be looking towards the slider event  as the Northerly becomes more in range   GFS Precipitation charts show quite a bit of snow for some parts on a stiff Northerly    Chesire gap in effect also

Edited December 4, 2017 by weirpig

[shaky]

Gfs not backing down here!!!amazing slider!!even better than the 00z i think?!!and cheshire gap streamer in full effect for hours on end for the midlands lol!!

Edited December 4, 2017 by shaky

[Day 10]

GFS still not back down keeping a wedge of high pressure further north.

GFS a bit further on

 

 

[warrenb]

Sliders, yeah, great program, the way they use to go through time, ah anyway, I can see and easterly brewing here, always remember the good old early eighties, always took two or three bites of the cherry before the goods arrived. These charts at the moment have that feel about them.

Edited December 4, 2017 by warrenb

[Nick F]

Yep, GFS sticking to its guns on the 06z, the precipitation from the slider system still too far SW to bring any snow though where it meets the cold air. 

The idea that GFS wants to undercut a block over Iceland is very intriguing, given the Euros don’t, which models will give in to who? The 12z output may or may not give us the answers! Which makes it all the more interesting model viewing.

Edited December 4, 2017 by Nick F

[warrenb]

I think the best way to describe the models at present is messy, flabby highs, indistinct patterns, tells me the models are struggling with something, just not sure what it is.