Model Output Discussion - The final stretch to Christmas

[Gibby]

Only by coincidence - There have been many, many times where the mean has been utterly wrong at that time frame because the signal gets watered down and eventually muted out

OK we'll have to agree to disagree but I have been studying these charts for years and while I appreciate what your saying I am not saying the chart is how things will look synoptically in 10 Days time but if there's a balance of Low pressure over High pressure towards a position North of the UK and High to the South you can bet your life that's the most likely option otherwise the chart would not be produced. The one thing I note run to run is that this chart changes slowly day to day in response to a cross section of each of its 50 members while every operational be it GFS, UKMO, ECM or whateverdoes and has been changing wildly of late and reflects just one permutation of many. I do agree though that the cluster postage stamps images are as good or a better guide to shifting trends than this chart in isolation. However enough of all that.

Happy Christmas everyone on Netweather.

[Cheese Rice]

The fax chart indicates snow for Yorkshire and parts of North West England.

Further south snow to rain to possibly back to snow again.

Going by the current output (fax/GFS/ECM/NMM) anywhere south of Yorkshire is not conclusive for significant snowfall.

[fergieweather]

Pretty much in line with the ECM

Highest risk around southern uplands in northern England.

Only trouble is, we are no closer to expressing confidence re outcome versus where we were 24hrs ago...UKMO go for track somewhere halfway-house between their 00z and 12z GM. Arpege looks essentially similar. But this saga will run to wire, with very fine thresholds to discriminate PPN type (thus ignore e.g. GFS snow charts, but I'd hope most people already do anyway until T+12 hrs!!)

[Captain Shortwave]

Day 6 from the GFS

Pretty poor with a milder flow establishing.

 

GFS (P)

A slacker and colder chart with some very cold air just across the English channel. A low moves west from northern Europe at day 7 which could provide some fun......

 

The trends today have been rather poor, especially the ECM which looks mild into week 2. That said things can always change given how thing have been recently. So no need for lost hope just yet

Edited December 24, 2014 by Captain shortwave

[Cloud 10]

A snippet from today's NOAA discussions pretty much says it all.

 

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE
TO CONTINUED POOR MODEL CONTINUITY AND LARGE SPREAD AMONG THE 6Z AND 0Z ECMWF
ENSEMBLE MEMBERS.

 

 http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

[Gowon]

Getting interesting again...

 

[fergieweather]

Only trouble is, we are no closer to expressing confidence re outcome versus where we were 24hrs ago...UKMO go for track somewhere halfway-house between their 00z and 12z GM. Arpege looks essentially similar. But this saga will run to wire, with very fine thresholds to discriminate PPN type (thus ignore e.g. GFS snow charts, but I'd hope most people already do anyway until T+12 hrs!!)

EDIT: clearly, if the southward bias of 12z GM & E4 proves correct (despite UKMO shift slightly N in modified output), then snow threat also shifts much further S).

[bobbydog]

you know what? its christmas eve. we cant change the weather. we can wish for snow or the models to change for the better. if that doesn't happen then there's nothing we can do about it. what we can do is enjoy time with our families, have a drink and watch our loved ones smile when they open their presents. so many people dont have that opportunity. if all we have to worry is the weather then we should count ourselves lucky.

merry christmas to you all, whatever the weather.

cheers!

Rob.

[Met4Cast]

GFS ones again sinks the high South-Eastwards and doesn't really get going with a Scandi high, GFS(P) however does manage to build heights towards Scandi and we start to see low heights over Europe edge very slowly Westwards.

 

Tamara mentioned earlier on that any model sinking the high South is probably being overally progressive and until we get the boxing day low sorted, anything happening beyond should be taken with a pinch of salt

[Joe Levy]

Battleground on the GFS(P)!

[swfc]

huge diff between gfs op and gfs -p?not sure why I look at this it sends me crazy.The op shows the obv outcome given the pv to nthe northwest and other models but who knows

[Barry12]

Tamara mentioned earlier on that any model sinking the high South is probably being overally progressive and until we get the boxing day low sorted, anything happening beyond should be taken with a pinch of salt

 

No offence to Tamara, but she's not always right. The high could easily sink. But I agree, anything can happen.

Edited December 24, 2014 by Barry95

[cyclonic happiness]

Owww, textbook battleground followed by undercut coming up me things on the GFSP :-)

 

At least I'll go to bed happy, just hope Santa brings some lovely weather over the next few days and 'merry Christmas to you all' :-)

+198 on the GFSP shows a hurricane storm just off the coast of SW" Ireland, we can forget it at this point :-D

[Gowon]

Let the battle commence..

 

[492]

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=6&code=0&mode=2&runpara=1

 

The upper ridge becomes cut off to the NE on the 18Z GFS P but extends ENE towards the southern Baltic on GFS.

A mugs game I know but I'm going to back the GFS  P tonight at around T+180 for the next chance of some snow. Even GFS suggests a cold frosty period for a large part of the UK with a drift originating from what looks likely to be a frigid continent.

[Snowman31]

Best thing to come out of GFS op 

 

Edited December 24, 2014 by Snowman31

[swfc]

Looking at the models today one thing that has been shown a few times is the arctic high pushing towards the scan-euro high.The pv is showing a huge split and the jet is heading south be it in fi.Just a chance that things in the coming weeks may get very interesting

[BlueHedgehog074]

Owww, textbook battleground followed by undercut coming up me things on the GFSP :-)

 

At least I'll go to bed happy, just hope Santa brings some lovely weather over the next few days and 'merry Christmas to you all' :-)

+198 on the GFSP shows a hurricane storm just off the coast of SW" Ireland, we can forget it at this point :-D

Indeed. That beastly Atlantic Low certainly isn't getting into the festive spirit on that GFS Parallel run - it's gotten itself into such a bad temper. Probably because it can't win the fight against the blocking High Pressure system to our North-East. I mean, come on Atlantic Low, it's nearly Christmas. Chill out will ya!  :smiliz39:

 

[Mucka]

Owww, textbook battleground followed by undercut coming up me things on the GFSP :-)

 

At least I'll go to bed happy, just hope Santa brings some lovely weather over the next few days and 'merry Christmas to you all' :-)

+198 on the GFSP shows a hurricane storm just off the coast of SW" Ireland, we can forget it at this point :-D

 

 

Very much so. Typical GFS FI bomb.

The hi res is good though with a nice link up and flow reversal.

GFS op seems very progressive though and collapses the ridge quickly but which is right?

[SW Saltire]

No offence to Tamara, but she's not always right. The high could easily sink. But I agree, anything can happen.

True but every call she has made this winter so far has come to fruition.

I distinctly remember someone demanding that Tamara et al explain why the cold hadn't occured yet and why this winter wasn't going the way she and most other experienced and knowledgable posters had predicted circa 5-10 days ago... (I can't exactly remember when) and yet we are looking at a cold few days at the very least which is much better than last year.

Maybe you can enlighten me when that post was made and by whom Barry?

Any clues?

Edited December 24, 2014 by SW Saltire

[Barry12]

True but every call she has made this winter so far has come to fruition.

I distinctly remember someone demanding that Tamara et al explain why the cold hadn't occured yet and why this winter wasn't going the way she and most other experienced and knowledgable posters had predicted circa 5-10 days ago... (I can't exactly remember when) and yet we are looking at a cold few days at the very least which is much better than last year.

Maybe you can enlighten me when that post was made and by whom Barry?

Any clues?

 

Yeah she said a pattern change during the middle to end of December, so she was definitely right about that. But the weather can make fools out of even the most knowledgeable posters.

 

Nope, I can't remember who made that post

[Snowman.]

Very much so. Typical GFS FI bomb.

The hi res is good though with a nice link up and flow reversal.

GFS op seems very progressive though and collapses the ridge quickly but which is right?

 

We shall see.

 

Lets hope the ECM gives us a decent run in the morning along with the para, I've got to the point where I glance at the OP then just forget about it.

Edited December 24, 2014 by SN0WM4N

[Midlands Ice Age]

Indeed. That beastly Atlantic Low certainly isn't getting into the festive spirit on that GFS Parallel run - it's gotten itself into such a bad temper. Probably because it can't win the fight against the blocking High Pressure system to our North-East. I mean, come on Atlantic Low, it's nearly Christmas. Chill out will ya!  :smiliz39:

 

24th dec gfs p the angry low.gif

 

I'll take that at eight days out as it is what I have been looking  for out in the sourh west,  Its negatively tilted and will send a breakaway low over south west Emgland.

HIgh risk, but what a reward!!! 

 

MIA

 

Edited December 24, 2014 by Midlands Ice Age

[Mokidugway]

Raging Atlantic for new year ,not to worry , it's Christmas ....

[Ice Day]

just a quick one from me, apologies for being a bit off piste!  This is a magnificent site (quite the best I've found on the internet) and there's several hundred of us who spend far too much time on here.  As it's Christmas, I just wanted to give thanks to the knowledgeable posters on here (we all know who they are) for making this such a valuable learning space and an extra special thanks to the mods who really have a difficult time trying to keep posters on topic and polite (especially when there's snow on the horizon) !!!!

 

We're really going to get what we want, whether it's this year or the next, a mega winter is just around the corner!

 

Happy Christmas everyone.