Model Output Discussion 4th Dec.2013-12z onwards.

[TSNWK]

6z gfs maintains the theme during Christmas week and beyond of something a lot more interesting for cold fans.. Just saying.. 2nd operational to say so.Be nice if the ensembles offered a little more support for this option than the 00z set did

Nope the 06z was isolated at the bottom of the pack, same as the 00z. I guess it's another one of those is it the dog wagging the tail(s) or the tail(s) wagging the dog questions.At the very least, I'm sure all of us, be mildies, coldies, professionals are just pleased to have something to discuss after the last few weeks. Cheers

[Purga]

Of course we could.... as with ANY other NWP product! That sort of possibility is always a given. Nonetheless: as I stressed earlier, last 3 runs have offered good continuity on *broad* expectations into Xmas period. The latest DET models into same time frame offer similar story. Nuances such as depth of cyclonicity; transient chillier spells of Pm or rPm flow etc are obviously beyond the realm or raison d'etre of EC32. Anyway... we move on.

Ian, i notice that the METO extended forecast today still hints at temps near normal -  'although there could be some colder nights in the south and east with a risk of frost and fog in places.'.

So I guess the Euro HP may still show its hand with a continental feed possible according to the longer range UKMO tools?

Edited December 13, 2013 by Purga

[phil nw.]

A reminder that this thread is for discussing current outputs

The latest charts may not be the greatest for Winter fans but discussing these are what this thread is for.

 

It may be that future runs- whether they be the ECM 32 day ens or our usual suites- will change but we are then speculating.

Let's keep what we may hope for in future outputs to the other Winter threads please all.

 

Plenty of choices to post general views not tied strictly to the current model runs here-

 

http://forum.netweather.tv/topic/78680-model-banter-moans-and-ramps-winter-201314/

http://forum.netweather.tv/topic/78715-the-gfs-count-down-to-christmas/

http://forum.netweather.tv/topic/78310-winter-2013-2014-discussion-part-2/

 

 

Thankyou.

[Frosty.]

That output is still low resolution at the moment though (T+192), so it might look different in a few days time. Looks interesting though, eh?  

There is actually cold zonality with snow on hills even before then, a dress rehearsal for the real deal maybe? at least it gives the experts something to think about.

[carinthian]

a nice summary of what happens there f without getting too deeply into what the euqations actually look like-frightening on your first forecast course is what I remember and going to sleep with them stuck on the walls of my bedroom study. Yuk, best not think too much about them as it could bring back nightmares.

John, I remember my old mentor Ross Barclay describing the equations set at Shinfield as being mysterious and puzzling and not to take much notice of them as they cannot change the weather. However, Ross was an enigma himself and a great Kiwi.

 C

[Frosty.]

The GEFS 06z mean shows a very disturbed outlook with gales, heavy rain, squally showers and cold enough in the north at times for snow, especially on hills and occasional colder incursions digging further south, no sign of stagnation returning for a long time.

[johnholmes]

John, I remember my old mentor Ross Barclay describing the equations set at Shinfield as being mysterious and puzzling and not to take much notice of them as they cannot change the weather. However, Ross was an enigma himself and a great Kiwi.

 C

 

without them any forecaster would be totally unable to first of all understand meteorology and secondly have nothing to be able to produce a forecast from. They are the rails on which any forecast human or model made are based. Terms like thickness advection, vorticity are all sound scientific formula that do work. The trouble is there are so many variables be it in short term forecasting or longer time scales that just one tiny change makes for massive differences down the line. There is a sound mathematical reason why forecasts for 24 hours ahead are very very much more accurate than day 10 let alone 30 or more.

But yes remember the old fella with affection, cigarette on answering the public lines,' nah you want the AA' in his wonderful N Zealand twang, being one of his favourites I recall!

[stewfox]

Ho Ho Ho...Brrr  ..Look at these festive charts from the Gfs 06z op run, untold riches compared to the prolonged stagnant mild outlook the models were showing recently, it looks like there could be a more pronounced wintry spell within the overall structure of the upcoming very unsettled pattern with some snow events as we reach christmas week..we were told it would take a long time to get back to anything remotely wintry, well it might be sooner than that.

 

I love your optimism all models suggest a spell of more mixed weather with cold/mile interludes. Very much a average December on the cards going forward with people looking for those 600ft hills to deliver. Buxton Christmas Shopping on 21st December looks good.

Edited December 13, 2013 by stewfox

[Frosty.]

The Ecm 00z ensemble mean shows a full on very unsettled outlook, stormy at times but the most severe weather probably across the northern half of scotland.... gusts in excess of 80-90 mph at times, very low heights to the northwest / north, occasional incursions of polar maritime sub -5 T850 hPa rushing across the atlantic associated with the bitter cold air being ejected out of canada into the northwest atlantic, it's substantially modified by the relative warmth of the atlantic but still packs a punch when it sweeps across the north of the uk and upland parts of the north have a good chance at significant snow cover at times, especially the higher hills and mountains with sub zero temps at munro level (3,000 feet ASL)..a potentially rather wintry and stormy outlook for the uk. 

Edited December 13, 2013 by Frosty.

[Iceaxecrampon]

Near apocalyptic on Sunday for the Faroes.

 

 

What pressure does that bottom out at?

 

Thursday 

 

 

 

One in FI for Christmas Eve.

 

 

 

Festive.......? 

 

Ian

 

 

 

 

 

 

[Summer Sun]

Near apocalyptic on Sunday for the Faroes.

 

h500slp.png

 

What pressure does that bottom out at?

 

Thursday 

 

h500slp (1).png

 

 

One in FI for Christmas Eve.

 

 

uksnowrisk.png

 

Festive.......? 

 

Ian

 

Not sure on the pressure 940's?

 

Its not much easier to see with the clear chart

 

[kev f]

Not sure on the pressure 940's?

 

Its not much easier to see with the clear chart

 

i make that 944mb

[Mucka]

I've been enjoying this mornings two outlier GFS Op runs, especially for NW England where the 06z actually trumped the cold outlier that was the 00z, 

 

http://www.meteociel.fr/cartes_obs/gens_display.php?x=236&y=40&ext=1&run=0&runpara=0&type=3

 

http://www.meteociel.fr/cartes_obs/gens_display.php?x=237&y=42&run=6&runpara=0&type=3&ext=1

 

This afternoon and evening will likely show something far more sensible but at least it adds a little more "fun" to the model watching now deep FI isn't locked in West/East zonal.

Edited December 13, 2013 by Mucka

[Gael_Force]

Not sure on the pressure 940's?

 

Its not much easier to see with the clear chart

 

 

It is better seen on the instant weather maps as the lowest figure is given at the bottom of the chart - in this case the low bottoms out at 942.5.

 

[nick sussex]

A small straw to clutch  from comments made by NOAA re the pattern in the USA and Canada which does have a bearing on us in western Europe:

 

THE UNCERTAINTY AFTER DAY 5...RESULTS FROM THE POSSIBLE"RE-EMERGENCE" OF A "NEW" AMPLIFIED PATTERN IN THE EASTERN PACIFICAND THE PLACEMENT OF A DEEP POLAR LOW OVER THE NORTHWEST HUDSONBAY. THE 12/12Z DETERMINISTIC GUIDANCE APPEARS TO BE STRUGGLINGWITH THE OUTCOME OF MARITIME PACIFIC AIR INTRUDING UPON NORTHWESTCANADA AS THE POLAR LOW RETROGRADES/MIGRATES ACROSS NUNAVUT. TOMITIGATE THE LARGE SPREAD AND UNCERTAINTY ALONG THE ARCTICCIRCLE...WPC BLENDED THE 12Z NAEFS/EC ENSEMBLES DAYS 6-7 FOR THEFLOW PATTERN OVER THE LOWER 48.

 

Theres not much sign of any re-amplification towards the eastern USA but that eastern Pacific region is quite important re any ridging into the Arctic from the Alaskan side.

 

If  we're looking for some changes in Europe I think its going to have to come from ridging into the Arctic which could put some forcing onto the pattern in terms of jet axis and placement north/south, essentially we could still be left with a zonal pattern but with a better chance of seeing some colder snaps as the jet edges further south. 

[summer blizzard]

Euro and UKMO both have a cooler shot at day 6 however GFS and GEM keep a much stormier and milder pattern.

 

[The Northern Ramper]

I feel the models are trending towards cool Zonality for Xmas, the bookies may be paying out yet.

[swfc]

Well the 12z drops the secondry low and looks better 850s wise at 126hrs.

[cooling climate]

 

I feel the models are trending towards cool Zonality for Xmas, the bookies may be paying out yet.

I would agree and would not be at all surprised to see a much more nw/se typepattern setting up across the country with much better potential for snowacross many parts if the troughing lies to the east of the UK.These are just my thoughts on where the models and weather is heading.

[Panayiotis]

Between 138hrs and 162hrs most of the UK sees -4C uppers, which is cold and able to produce snow on higher ground, with sleet possible on lower ground:

With this kind of pattern, moderate to heavy showers are driven off the Atlantic in a windy NW/W wind, with sunshine in between. Not as bad for the coldies than originally thought!

Edited December 13, 2013 by Panayiotis

[TonyH]

i make that 944mb

Snap!

[Barry12]

A turn around looks possible to me here, Christmas is not written of just yet.

[TSNWK]

No heights building over the pole this time in early low res..expecting a less interesting run from here for coldies.

[Chess01]

A turn around looks possible to me here, Christmas is not written of just yet.

Was never a write of in the first place pathetic the people who think it was . Just last week the models were showing Bartletts now they show the opposite . Wait until thursday and we should know if we are going to see some festive weather

[Panayiotis]

LOL 

Edited December 13, 2013 by Panayiotis