Model output discussion - 1st December onwards

[johnholmes]

in the here and now again; the warm air came in here after 1200 when T was 4.4C now it is on 9.9C; the low looks to be tracking to a bit north of Flamborough Head and into the N Sea.

The main rain area has caught parts of Cumbria, not sure of totals there, the highest I have seen are Valley (Angelsey) with 19.0mm and Isle of Man with 15.0 mm.

 

And for a long way ahead the latest from NOAA re ENSO

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.pdf

Edited December 12, 2015 by johnholmes

[Sperrin]

Models didn't judge the band of PPN well at all, it pushed much further north than anticipated. Not complaining as this sight greeted me this morning.

That's three separate days of lying snow in mid Tyrone area at modest altitude. 

[Geordiesnow]

4 hours ago, kev238 said:

This December clearly has had overwhelming signals for a mild zonal flow which is coming to fruition

sometimes it is best to concede that cold weather is unlikely in the next 3 weeks and this is one such occasion 

Why concede it when there is cold weather right now with snow in places and a hard frost forecast for the Northern half of the UK tonight nevermind giving up on it for the next 3 weeks...

Next week is one of turning milder which will eventually get into Scotland with potentially by Wednesday and Thursday we could be seeing temps widely in the mid teens and who knows, maybe we could see temperature records broken. What happens after that is not so certain, could turn cooler but stay fairly mild.

Looks like most of any rainfall will be in the South and West and sunshine amounts will probably be on the low side but some interest in respect just how mild it will get mid week. 

[Mucka]

No sign of blocking setting up by Christmas as yet so any cold will come from a deep trough and timing will be everything as any cold will be temporary.

If we can get a trough to push far enough South and increase the gradient by building a ridge behind then a white Christmas is still possible but it looks less the further South you get.

In general terms the influence of Euro high is set to diminish from around day 8. This means increasingly unsettled conditions again into the last 3rd of December (from around 20th onward). there is potential for some storminess in the run up to Christmas. From here will likely have a trough set up somewhere to the North of the UK and positioning and orientation will dictate how much PM air we can drag in and how far South it gets.

[Ali1977]

High pressure pushing a little on the PV over in Canada, not sure if this will help us get some better PM air later down the run...

[Jeremy Shockey]

some much cooler projected temperatures appearing 24th - 26th Dec

[IDO]

I have noticed the trend on the GFS over the last couple of days is to prolong the ridge and the 12z continues that theme. Right out to D8-9 now and the advantage of this is it keeps the milder uppers going:

D8:    

From then it is very consistent with a flatter pattern as the PV travels west to east to the North of the UK.

D10:   GEM similar: 

UKMO still getting with the plan but at D6 it is now in the right ball park: 

   GFS: NH profile at D14:   Current: 

GFS still keen on a 2-3 day trough of cold uppers passing through the UK Christmas Eve into the big day, so potential for snow in the west/North, though too early yet to be more than hopeful as uppers are borderline and with the prolonging of the ridge next week this could change. By then the NH profile is pretty dire with the trop PV beginning to become a monster as it catches up with the strat cooling. That should sink the jet further south and kill the anomalous warmth of Nov/Dec as PM and AM transient flows become more dominant. 

[ricey076]

7 hours ago, kev238 said:

This December clearly has had overwhelming signals for a mild zonal flow which is coming to fruition

sometimes it is best to concede that cold weather is unlikely in the next 3 weeks and this is one such occasion 

Wish I could forecast the weather three weeks in advance..!

[Daniel*]

Christmas Day on the latest GFS looks interesting for snow lovers (the period has some support for a 'cold spell' so it cannot be discounted).

The secondary low would cause a snowfall strikingly similar to last years Boxing Day snow, which came out the blue and I feel this is definitely possible this year.

Somethin' for coldies to look out for even for southern peeps.

 

Edited December 12, 2015 by Daniel*

[cheshire snow]

GFS has been toying with the idea of Christmas cold snap for a few days

Now,for me if its still showing this time next week,i might start to take

Notice,pre that possibility more rain and mild temperatures for the Next

10 days or so,over to the ECM

C.S

[January Snowstorm]

Both the ecm and gfs agree on the pv strengthening in the lead up to Christmas. Could be some very disturbed and stormy weather in the run in.

As for Christmas too early to call but at the moment it certainly doesn't look dry and frosty. Polar air never too far away and Northern hills have a decent chance of grabbing at least some wintriness 

[Captain Shortwave]

11 minutes ago, January Snowstorm said:

Both the ecm and gfs agree on the pv strengthening in the lead up to Christmas. Could be some very disturbed and stormy weather in the run in.

As for Christmas too early to call but at the moment it certainly doesn't look dry and frosty. Polar air never too far away and Northern hills have a decent chance of grabbing at least some wintriness 

Have to agree with this.

Heavy rain and gales for most if the ECM is close to the mark. The GFS does hold the jet further north at this point but the ensembles do give the ECM a lot of credence in its output.

Day 8 and 10

So a period where stormy conditions could occur quite widely between the the winter solstice and Christmas.

Beyond this....

Perhaps signs that the zonal period could be short lived with another ridge building to our east with a sharpening Atlantic/UK trough, actually the GFS op looks likely to be responding to this sharpening pattern with its low resolution signal. This could be a precursor signal to something more significant if we can get some decent ridging towards the pole from Europe/Scandinavia.

So still a case of looking for signals to bring stratospheric warming and wave breaking towards the end of the month which could bear fruit later on. As for the rest of December, it is a case of hoping we can get lucky with some polar maritime or Arctic maritime incursions, especially those further north who today have seen this little bit of luck in a predominantly mild pattern.

Edited December 12, 2015 by Captain Shortwave

[BLAST FROM THE PAST]

6 hours ago, johnholmes said:

Just wondering Fred where your cold spell for the South has got to. Even the North has so far had just shortish cold spells?

As you can see fro a post a little before this I still see no more than short bursts of Pm air?

your thoughts?

Posted my thoughts the other day John on this thread re this, no hiding no looking for excuses and it was for wintry weather even for the south and I hope u remember I posted I'm not expecting anything like a Dec 2010? Trough 500 miles east and it was game on but trough has hung SW of us, I'm not too down beat as some pretty interesting weather looks likely ahead.  One can try.  As I said too I greatly respect your ability and experience and I was hoping for you to post that your way comes on board...unfortunately not...but I'll keep trying

 

regards

 

BFTP

[MP-R]

3 minutes ago, Captain Shortwave said:

Have to agree with this.

Heavy rain and gales for most if the ECM is close to the mark. The GFS does hold the jet further north at this point but the ensembles do give the ECM a lot of credence in its output.

Day 8 and 10

So a period where stormy conditions could occur quite widely between the the winter solstice and Christmas.

Beyond this....

Perhaps signs that the zonal period could be short lived with another ridge building to our east with a sharpening Atlantic/UK trough, actually the GFS op looks likely to be responding to this sharpening signal with its low resolution signal. This could be a precursor signal to something more significant if we can get some decent ridging towards the pole from Europe/Scandinavia.

So still a case of looking for signals to bring stratospheric warming and wave breaking towards the end of the month which could bear fruit later on. As for the rest of December, it is a case of hoping we can get lucky with some polar maritime or Arctic maritime incursions, especially those further north who today have seen this little bit of luck in a predominantly mild pattern.

I would tend to agree with this, not because I'm looking for cold/average December weather at least, but because some of the default PV-monster charts being spurted out at the moment are rather indicative of the El Nino continuing to strengthen, which I'm pretty sure is no longer happening. I would expect downgrades in the strength of the PV over future runs with slightly less catastrophic charts as a result. Not to say a quick route to something more seasonal as I think there many hurdles to cross before winter arrives nationwide.

[Frosty.]

7 minutes ago, BLAST FROM THE PAST said:

Posted my thoughts the other day John on this thread re this, no hiding no looking for excuses and it was for wintry weather even for the south and I hope u remember I posted I'm not expecting anything like a Dec 2010? Trough 500 miles east and it was game on but trough has hung SW of us, I'm not too down beat as some pretty interesting weather looks likely ahead.  One can try.  As I said too I greatly respect your ability and experience and I was hoping for you to post that your way comes on board...unfortunately not...but I'll keep trying

 

regards

 

BFTP

Fred you deserve lots of credit for doing a LRF as you have been doing for years, at least you made the effort and this winter is still in it's infancy, tons of time for northern blocking and cold spells. : )

[BLAST FROM THE PAST]

16 minutes ago, Frosty. said:

Fred you deserve lots of credit for doing a LRF as you have been doing for years, at least you made the effort and this winter is still in it's infancy, tons of time for northern blocking and cold spells. : )

Cheers bud that is appreciated....it was a chance on my method and we could still get a buzz pre/at Christmas but more of the same is fav.   The BEST chance though for pukka cold set up between RJS and I [this Dec period was a cold shot chance seen by me not RJS] still remains for late Jan and early Feb. 

 

BFTP

Edited December 12, 2015 by BLAST FROM THE PAST

[johnholmes]

2 hours ago, BLAST FROM THE PAST said:

Cheers bud that is appreciated....it was a chance on my method and we could still get a buzz pre/at Christmas but more of the same is fav.   The BEST chance though for pukka cold set up between RJS and I [this Dec period was a cold shot chance seen by me not RJS] still remains for late Jan and early Feb. 

 

BFTP

Thanks for your honest response Fred. Fingers crossed that the weather will play ball and give a more seasonal touch over the festive period. A rather stormy period seems on the cards over the next week, maybe even out to 2 weeks.

NOAA anomaly charts beow supporting this fairly solidly for some days.

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

Edited December 12, 2015 by johnholmes

[Nick F]

A look at the 12z EPS mean/Anomaly for 850 hPa suggests an easing off by day 10 from the ridiculously high temp anomalies expected next week. 

T+120

T+240

By day 15 in the extended, blues (-ve T850 anomalies) across western UK with eastern areas average.

The 500mb by day 15 indicating the euro high has been flattened a lot by then with lower heights across much of Europe indicative of the jet stream shifting south.

whether this is a trend or not remains to be seen though ...

Edited December 12, 2015 by Nick F

[Ali1977]

This could be good for Xmas day...shame it's FI

wrong !!!

 

Edited December 12, 2015 by Ali1977

[Nick F]

Indeed, just for fun, some snow potential for the northern half of the UK on the big day, cold front across central areas which clears the south overnight with all parts in a cold PM flow on Boxing Day with wintry showers.

Trouble is, time and time again we see these cold wintry PM teases only to be scuppered by secondary lows developing out west to cut-off or limit these cold bursts ...  though I will try not to worry over It, especially as it will probably change for 25/26th!

Edited December 12, 2015 by Nick F

[Bullseye]

Those hoping for change in time for Christmas might like the sound of this: https://twitter.com/epawawx/status/675803698237435904

[Daniel*]

2 hours ago, Bullseye said:

Those hoping for change in time for Christmas might like the sound of this: https://twitter.com/epawawx/status/675803698237435904

And this...

 

 

[Rocheydub]

I may be wrong here, but does phase 7 not have implications for  CONUS getting colder??? I seem to recall it had a negative effect on our cold ambitions, especially with negative temp anomalies on east coast USA meant some rapid cyclogenesis spinning Atlantic storms our way!

[Daniel*]

1 hour ago, Rocheydub said:

I may be wrong here, but does phase 7 not have implications for  CONUS getting colder??? I seem to recall it had a negative effect on our cold ambitions, especially with negative temp anomalies on east coast USA meant some rapid cyclogenesis spinning Atlantic storms our way!

As you can probably gather i'm not getting much sleep tonight.

Nope very beneficial indeed for the UK there are no negative as far as I know phase 7/8 are the holy grail for a cold blocking pattern I believe. I think it's highly unusual to go to such an amplified phase during a strong El Niño. It does help force a pattern change in our latitudes I think January could be quite special! If the MJO goes into phase 7 - cautiously confident we'll face a big flip the Netweather winter forecast of a SSW in early January seems like a very decent call to me (without going too flamboyant). I do think something significantly colder is in the offings post the new year, I really do, we will see as always. I have niggling feelings for these things and I'm getting that right now. Night folks. 

Edited December 13, 2015 by Daniel*

[knocker]

Some thoughts on this morning's gfs. Still in the mobile westerly regime which will bring periods of rain and strong winds (no obvious major storm on the horizon) with temps above average, sometime significantly so for a time. The temps tend to return to around average after day nine with the advent of a little channel low. (which of course probably will not be there on the next run. Xmas day is looking quite cool and unsettled but this will also obviously be subject to change

Charts weatherbell

 

Edited December 13, 2015 by knocker