Model Output Discussion

[MR EXTREMES]

http://www.meteociel...20-21.GIF?13-05

http://www.meteociel...44-21.GIF?13-05

GREAT UKMO

Like I said--- just wait & see........

s

thats the one steve,

i hope this chart comes of this is old skool low pressure into europe strong easterly and look at the alantic,

sorry closed lol.

its all on again but still im sure someone will have something to complain about.

fantastic stuff.

[i luv snow]

Hmmm yes Kold but how many times have we been tehre with GFS? It keeps showing a breakdown, and 100% underestimates the might of cold, and breakdowns get pushed back and pushed back, as we know GFS tends to be over progessive... time will tell though

[kold weather]

Oh your quite right I Luv Snow, just something to note that there is strong support from the GFS ensembles, meanwhile the ECM ensembles doesn't realy show much in the way of scatter away from cold till around 264hrs which may suggest that the GFS is somewhat progressive in the pattern change. As you say we've seen it so many times in blocking situations.

[tinybill]

this must be pure gold for snow lovers just in time for xmas !!!!

[AtlanticFlamethrower]

When I post I speak for London - with 7.5m people what happens to London, rather than the hills, defines the spell of weather IMO.

With that in mind 06z is another downgrade.

Successive model runs have pushed the easterly south and east into Europe. We do not get a feed of -10 air and temperatures cold enough for snow (520 dam).

The reason for the false over-excitement: the models don't take account enough of the effects of the warm North Sea. If the North Sea was a mean 8C rather than 10C the air over us would be cold enough for longer. Instead of London receiving sleet it would get laying snow.

[Tim Bland]

I think it is worth mentioning with regards the Models that different Models Perform better or worse at different stages on their Output. I will give you a for instance and this is regularly used by NOAA When we Chase Tornadoes in the States.

GFS - Better for spotting trends at further range from about T168 To T240

We then use the ECMWF & UKMO For a better idea of finer details within the 2-5 day range and so do NOAA & The SPC

ECMWF & UKMO Better for T48 To T120

Then over in the States everyone discards those 2 Models for the RUC for the Mesoscale and Finer details from T0 To T48

Maybe the Models we use here should/could be interpreted in the same way ??

Just a suggestion for all the wrist slitting that goes on when everyone pins their hopes on 4 GFS Runs a day

Paul S

Excelent post Paul, thanks for sharing that. IMO us amateurs follow the GFS most closely purely because we have free access to it and the charts are interpreted for us into precip type and snow depth etc. I would much prefer NW to interpret the UKMO / ECM. I have a friend who is a meteorologist for Meteo group and she said she only looks at GFS occasionaly when there is a wobble with the ECM / UKMO. She also only looks at the Ensemble output from the GFS.

[Rollo]

Just a word about the possible breakdown,this spell has at this stage got the hallmarks of and old fashioned period of cold and snow,referring back to the spell of 62' in particular,there were many expected breakdowns but cold air to both the North and the East reasserted itself sometimes at the last minute and we remained in the bitter cold. We ARE dealing with a different era but these things are worth bearing in mind as the country is evenyually going to be covered by an area of very cold air indeed.

[Guest North Sea Snow Convection]

On the Bbc website , the guy says it is gonna get even colder with a tight and bitter easterly wind , then he finishes the forecast by saying cold enough even for some snow with a massive smile on his face.

It has to be mentioned that the parallel run is horrible with the Atlantic taking over by the end of the week .

Again, I think that discussing breakdowns is getting way too far ahead before a) the main cold spell has hardly begun and because there isn't agreement yet in terms of the easterly at the end of the week and so what happens from there depends on such agreement.

GFS is very probably being way too progressive - much as one would expect it to be. But as I said, much better to concentrate up to t120 and t144 first and until that is agreed on - the rest is immaterial atm.

[John Snow]

Am absolutely shaking in shock here at the charts particularly the ECM which now has to be considered the winner, anyone under the age of about 35 is going to see a snowfest they have never seen in their lifetime with chronic drifts and several feet of lying snow, most of the north will have 3-4ft of lying snow with 20-30ft drifts by this time next weekend when the ECM comes off, not so good down here but even I am quite confident of 4 or 5 inches

This event from Thursday onwards is goiing to absolutely bring the country to its knees and is reliable timeframe now.

I am 31 and have never seen anything like this

[funkymonkey15]

The ensembles are very strongly agreed upon a mild breakdown by the 22-23rd of December, I think there can't be more then 2-3 runs that are cold after that date as nearly all of them pump up the Atlantic low to at least 960mbs and make it a very large system...

However they aren't going to see shortwaves that will likely siphon off quite a bit of the energy that the model shows going into the main Atlantic low...I suspect they are also under doing the strength of the upper high...

I think the most striking thing though is the continuation of the strong southerly jet, much further south than we are used to during most recent winters.

[Frosty.]

GFS is very probably being way too progressive - much as one would expect it to be. But as I said, much better to concentrate up to t120 and t144 first and until that is agreed on - the rest is immaterial atm.

I think the gfs is underestimating the blocking potential from this deep cold which now looks like covering the whole of the uk and western europe, I just cannot believe it will get blasted away as easily as the 00z gfs showed, hopefully the ecm has a better handle on things and we stay locked in the freezer until the new year.

[Guest North Sea Snow Convection]

Just a word about the possible breakdown,this spell has at this stage got the hallmarks of and old fashioned period of cold and snow,referring back to the spell of 62' in particular,there were many expected breakdowns but cold air to both the North and the East reasserted itself sometimes at the last minute and we remained in the bitter cold. We ARE dealing with a different era but these things are worth bearing in mind as the country is evenyually going to be covered by an area of very cold air indeed.

This is also very true. There is no doubt that at some stage the atlantic will try and return and the models will try to force the energy right through the block. But it is very unlikely to happen that way.

Besides, whose interested in a breakdown atm when there are possibly very exciting times to come first of all!

[snowmadchrisuk]

Excelent post Paul, thanks for sharing that. IMO us amateurs follow the GFS most closely purely because we have free access to it and the charts are interpreted for us into precip type and snow depth etc. I would much prefer NW to interpret the UKMO / ECM. I have a friend who is a meteorologist for Meteo group and she said she only looks at GFS occasionaly when there is a wobble with the ECM / UKMO. She also only looks at the Ensemble output from the GFS.

It would be nice if Net weather could get a licence for some of the other models that we don't see and make it part of a Net weather Extra package or something.

Wednesday afternoon looks Cold enough for some snow IMO.

[Paul]

Locking this one now, fresh general discussion thread now open: