Model Output Discussions 06z 04/11/16

[phil nw.]

Following this little cold spell we do see the falling Greenland heights imposing themselves for a few days from the week end but looking at the ensembles they look transient and there is every indication of a change back to colder weather after mid-month.

A look at some NW Extra charts for Height and Temperature anomalies show the change-these are 3 day mean charts.

Notice too that the Atlantic doesn't get much further east than the UK/N.Sea with the cold block of air remaining across Scandinavia,Central and Eastern Europe-signs of a weaker jet.

[Frank Trough]

11 minutes ago, Catacol said:

I guess it depends where you are. For those in the south and west a northerly rarely delivers though a cold NW stream over the Irish Sea can bring snow showers. However the best setup down here is either a trough moving in on a SE feed from a low pressure sitting under a Scandy/Russian high (as per Feb 91) or a proper warm/cold collision event causing stalling and heavy snow. I'll never forget Feb 96 in that regard.

 

Both require high pressure in situ. As you live in Poole I doubt  you would get much from a mid atlantic or Greeny ridge / scandy trough scenario which I assume is what you are hoping for instead?

A little ice-age is probably what we need down here to avoid the dreaded "rain on the coast" scenario. December 2010 did deliver snow to this area but nowhere near as much as other areas in the south. A stonking proper easterly with genuine cold uppers and a sliding channel low would be what I would I pick personally IMBY.

[karlos1983]

45 minutes ago, Catacol said:

I guess it depends where you are. For those in the south and west a northerly rarely delivers though a cold NW stream over the Irish Sea can bring snow showers. However the best setup down here is either a trough moving in on a SE feed from a low pressure sitting under a Scandy/Russian high (as per Feb 91) or a proper warm/cold collision event causing stalling and heavy snow. I'll never forget Feb 96 in that regard.

 

Both require high pressure in situ. As you live in Poole I doubt  you would get much from a mid atlantic or Greeny ridge / scandy trough scenario which I assume is what you are hoping for instead?

Nope, wasn't IMBY at all. Just saying that an Easterly from Russia or "The Beasterly" are as rare as rocking horse crap", so watching them edger ever closer to the UK, so stop short by 150 miles, is disaster, and so much has to fall into place. 

In any case, no easterly showing in the output.

Edited November 8, 2016 by karlos1983

[Frosty.]

The GEFS 6z mean shows the Azores high ridging in by the end of this week and early next week introducing milder air across the uk and more settled conditions for the south of the uk for a time but further ahead it becomes more unsettled / trough dominated from the northwest which continues into late november with temperatures generally around average.

Edited November 8, 2016 by Frosty.

[Ali1977]

So the mild model has flipped to cold for Dec....Scandy high anyone 

[bluearmy]

3 minutes ago, Ali1977 said:

So the mild model has flipped to cold for Dec....Scandy high anyone 

Slider alert !!!

if that is anywhere close to reality, which being CFS it won't be !

[northwestsnow]

2 minutes ago, Ali1977 said:

So the mild model has flipped to cold for Dec....Scandy high anyone 

Fits my thoughts perfectly, Greenland high/scandy trough followed by a true block over scandy with the Atlantic attempting to get in as we head into December.

The signal for NH blocking certainly gathering momentum.... likey !

[karlos1983]

Nice sausage Scandi High would be the prefect Christmas present 

[Frosty.]

It looks like we are in for a westerly burst according to the ens mean and met office update but the majority of unsettled weather probably reserved for the northwest of the uk with the south / southeast having longer fine spells but with occasional changeable / unsettled phases and temperatures recovering, even mild at times during the next few weeks. 

Edited November 8, 2016 by Frosty.

[Catacol]

From this :

to this in pretty quick time

 

 

So very different to recent years. Atlantic has no depth to its umph - blocking very much the form horse. Accepted this is medium range output, but to see depressions forecast to fizzle out like this in November is the sort of pattern we snow seekers have been anticipating for several years now.

 

[feb1991blizzard]

19 minutes ago, karlos1983 said:

Nice sausage Scandi High would be the prefect Christmas present 

A telephone receiver is the best scandi high you can get.

[Seasonality]

5 minutes ago, feb1991blizzard said:

A telephone receiver is the best scandi high you can get.

Got an example of that you could post?

[white crimbo]

Not even a merest whiff of that Shannon entropy will do me fine 

[Catacol]

5 minutes ago, Seasonality said:

Got an example of that you could post?

Even got the finger dial :-)

 

[Frank Trough]

18 minutes ago, Catacol said:

From this :

to this in pretty quick time

 

 

So very different to recent years. Atlantic has no depth to its umph - blocking very much the form horse. Accepted this is medium range output, but to see depressions forecast to fizzle out like this in November is the sort of pattern we snow seekers have been anticipating for several years now.

 

as a note of caution, those charts are still 10 days away? Let's hope we get a smooth transition to the more reliable like in 2010.

 

*edit* my screen was covering your last sentence!

Edited November 8, 2016 by Certain kind of fool
astigmatism

[feb1991blizzard]

2 minutes ago, Seasonality said:

Got an example of that you could post?

 

See where the edge of the high hangs over the low, it looks like one of those old phones, its great because the curve in the isobars (denotes more chance of disturbance in flow giving chance of more prolonged outbreaks of snow).  This isn't the best example of the shape, theres better examples of a more receiver lookin pressure pattern but I thought I would show this because it gave the biggest dumping ive ever seen.

[Mucka]

Good afternoon all, tremendous update from Fergie and the MetO and I think we can now have high confidence that blocking will return fairly quickly after a very brief more unsettled spell. I'm actually finding hard to remember the last typically autumnal wet and windy day even here in the North of England - phenomenal.

The only caution is as to whether blocking will set up favourably for our little Island to become the bulls-eye of any polar darts but even that is of lesser concern than might be usually the case in a lackluster winter - given the blocking is expected to be fairly persistent it will move around and re-orientate itself through the coming weeks so at least a couple of cold spells should be expected so long as we don't have an unexpected turn around and zonal signal takeover.

The actual ECM and GFS ensemble graphs clearly show a marked cooling in second half of November now - a strong and welcome signal for cold fans.

 

I suspect the toughest part will be keeping expectations in check - especially with cold rampers like me around. 

[Paul]

Matt's latest synoptic guidance blog is online - a cold start to this week but likely to turn milder at the end:

http://www.netweather.tv/index.cgi?action=news;storyid=7759;sess=

[Frosty.]

17 minutes ago, Mucka said:

Good afternoon all, tremendous update from Fergie and the MetO and I think we can now have high confidence that blocking will return fairly quickly after a very brief more unsettled spell. I'm actually finding hard to remember the last typically autumnal wet and windy day even here in the North of England - phenomenal.

The only caution is as to whether blocking will set up favourably for our little Island to become the bulls-eye of any polar darts but even that is of lesser concern than might be usually the case in a lackluster winter - given the blocking is expected to be fairly persistent it will move around and re-orientate itself through the coming weeks so at least a couple of cold spells should be expected so long as we don't have an unexpected turn around and zonal signal takeover.

The actual ECM and GFS ensemble graphs clearly show a marked cooling in second half of November now - a strong and welcome signal for cold fans.

 

I suspect the toughest part will be keeping expectations in check - especially with cold rampers like me around. 

I'm a cold ramper too but after the current cold is over it looks like a return to more average conditions with some milder / cooler phases with the most unsettled weather across the NW and the least unsettled further SE.

[fergieweather]

1 hour ago, Ali1977 said:

So the mild model has flipped to cold for Dec....Scandy high anyone 

Yup. Very similar (for once) composite signal to both November's ECMWF and latest GloSea.

[phil nw.]

26 minutes ago, Frosty. said:

I'm a cold ramper too but after the current cold is over it looks like a return to more average conditions with some milder / cooler phases with the most unsettled weather across the NW and the least unsettled further SE.

Yes agree Frosty.

Just musing around the probable pattern from day 10 the ens do show the Greenland trough dropping south east and a lot depends on the positioning of this.Those lowering heights being squeezed south east by the pincer redeveloping +ve height anomalies to the north west and the N.Russian heights.

It will turn colder if the ens are correct-after the coming milder spell but if we can get that trough a little further east that does open the door to another northerly rather than a cooler cyclonic setup currently modeled.

[Mucka]

37 minutes ago, Frosty. said:

I'm a cold ramper too but after the current cold is over it looks like a return to more average conditions with some milder / cooler phases with the most unsettled weather across the NW and the least unsettled further SE.

Indeed, looking a little beyond that time-frame though Karl 

There shouldn't be much mild about though with winds quickly swinging to the NW mid month and then probably N,NE later in the month. (That's the plan anyway)

 

Edited November 8, 2016 by Mucka

[swfc]

low exiting esb scuppers the heights pushing north on the 12z.suck it and see i guess!!!

[Ali1977]

This run so different from the last past day 10, to be expected although it was similar up till day 10. I think the next few days it may be a case an looking at patterns within the ENS rather than the Op. hopefully they keep trending down temp wise. 

[Geordiesnow]

50 minutes ago, Frosty. said:

I'm a cold ramper too but after the current cold is over it looks like a return to more average conditions with some milder / cooler phases with the most unsettled weather across the NW and the least unsettled further SE.

You could say above average conditions potentially, especially if that Azores high noses in which it should now, the blocking is not going to fend that off thats for sure,

So a mild Saturday with rain around for some parts, slightly cooler for Sunday before potentially milder still with a more NW/SE split developing in terms of wet weather, the exceptional mild may not last but at this moment in time, the PV is forecast to ramp up across Greenland and any ridging too my eyes is way too far out to get excited about. You think going by the posts on here, its guranteed.