Model Output Discussion - The Start Of Winter

[nick sussex]

Overall the pattern is well agreed on but because of issues upstream the extent of any colder conditions re the PM flow into the UK is open to revision.

 

The ECM splits up the PV but still leaves a chunk near Greenland, the models agree on pressure rising to the east which will slow down low pressure, we don't see much if any trough disruption and so it looks a bit of a stalemate.

 

Temperature wise its not perhaps what we're used to in mobile patterns, we're often subjected to the mild mush variety but it generally looks average to colder at times.

[bluearmy]

Won't verify but would the trough disrupt and slide on the ecm day 11 ??

[gottolovethisweather]

It's also a cold run with day 4,5,8,9,10 all having -4 uppers for many of us. The Polar Vortex is almost completely destroyed. Not a bad run at all!

 

 

Very much agree Barry, although PV destroyed might be over-egging it, but that matters not.

 

As I often view the ECM 12zs in isolation and don't study the 0zs as much, this trend to colder has been building somewhat over the past few days. I would tentatively suggest that we are looking at a cold December overall with primarily a PM flow during the first half of the month and once we get some settled snow at higher elevations, who knows where things might lead beyond the realms of the current model projections. Looking tasty for cool to cold conditions to develop with cross-model consensus is my broader view of the current NWP suites. Not where many of us thought we would be heading, this time last week, but the trending ECM evolution and the UKMO to some degree prove the colder trend, especially when one looks at the NH picture and doesn't cling onto daily specifics at the surface re: rain or snow at longer timescales. 

Edited December 3, 2014 by gottolovethisweather

[johnholmes]

But there is a lot of energy still lingering in NE Canada.

 

And at 9 days just what is the point of comparing the 00z to the 12Z?

[terrier]

Not overly enthusiastic with the model output this evening looks like a watered down version of last year. Yes there is some pm air in the mix were Scotland and the far north of the uk would see snowfall. But for the majority of us it looks like a lot of rain with gales for the foreseeable future.

[Barry12]

And at 9 days just what is the point of comparing the 00z to the 12Z?

 

Surely it's better than looking at one run in isolation?

[gottolovethisweather]

Not overly enthusiastic with the model output this evening looks like a watered down version of last year. Yes there is some pm air in the mix were Scotland and the far north of the uk would see snowfall. But for the majority of us it looks like a lot of rain with gales for the foreseeable future.

 

Last year will soon be banished from our memories and should be.   Nothing like it synoptically speaking, except for some occasional rain and gales in the coming days for those unfortunate not to have snow. Remember that white iced crystal stuff guys n gals, yes it's in the forecasts once again, stay tuned. 

 

I'm sure the likes of Lorenzo, Chiniomaniac or whoever can add a bit more detail as to why the 2013 weather pattern is most unlikely to rear its ugly head again. 

Edited December 3, 2014 by gottolovethisweather

[Snowman.]

Not overly enthusiastic with the model output this evening looks like a watered down version of last year. Yes there is some pm air in the mix were Scotland and the far north of the uk would see snowfall. But for the majority of us it looks like a lot of rain with gales for the foreseeable future.

 

A watered down version of last year would just be a normal winter. 

 

The rain and wind is what stood out last year and water them both down and we have a normal winter. Obviously you're missing the bigger picture which is the disruption to the flow of the PV.

 

Plus it's the 3rd and if you're expecting mass snowfall half way through December then you need to lower your expectations mate.

Edited December 3, 2014 by SN0WM4N

[Polar Maritime]

Let's stick to Model Output in here please.

 

Thanks, PM

[Mike Poole]

A word on the model verification statistics, here's the 5 day graph:

There's clarification on what the PR... models are:

PRX: Experimental T1534 Semi-Lagrangian GFS run by NCEP NCO PRHW14: Experimental T1534 Semi-Lagrangian GFS run by NCEP EMC

 

New GFS run in two different places maybe? 

 

I'm rather dissappointed if so, I've had my eye on the PRHW14 most of the year and it's a bit better than GFS, close on UKMO but still short of ECM - if this is now the highest resolution model, it is a bit underwhelming.

[ItNeverSnowsInWindsor]

Yes its great to see a smashed polar vortex still modeled at the end of runs. It has to be a help going forward.

 

Tonights final frame of the ECM literaly shows the PV looking like a sad face (purple bits)

 

But is it helping us in the UK ? So far we haven't had a flake of snow since the winter before last.

[Polar Maritime]

I've just deleted some more posts, Again for those it concerns, Please stick to Model Discussion only.

Edited December 3, 2014 by Polar Maritime

[Team Jo]

'Watered down version of last year' is a bit of a rash assessment...

[Barry12]

But is it helping us in the UK ? So far we haven't had a flake of snow since the winter before last.

 

The chances of getting cold to the UK are significantly higher if the Polar Vortex is weak. Also, some of us did see snow last winter.

[Skyraker]

I dont think i've seen -4 covering almost all of the north Atlantic.

Is -8 possible? Any historical charts out there?

[swfc]

I dont think i've seen -4 covering almost all of the north Atlantic.

Is -8 possible? Any historical charts out there?

there only 850s temps tbh

[Skyraker]

there only 850s temps tbh

Yeah I know mate, but -8 isotherm and PM airmass should give snow to lower levels..

[ItNeverSnowsInWindsor]

Yeah I know mate, but -8 isotherm and PM airmass should give snow to lower levels..

But by the time it reaches UK, the airmass is heavily modified and it's usually borderline getting snowfall to low levels. We need a strong NW' airflow really.

[blizzard81]

DeBilt 10 day ECM ensembles. A steady colder trend from 10th December

 

[MPG]

cant post a chart (no idea how to on this forum!). GFS trending continually out in FI pushing heights (500hpa) into Greenland from NE Canada. Trend appearing?

Edited December 3, 2014 by Polar Maritime
Just copy and past the link or chart.

[blizzard81]

Would love to see the control run, it falls off the cold cliff

is that an easterly I wonder?

 

 

 

 

It seems very similar to the Op up to day 10 as well

Edited December 3, 2014 by blizzard81

[knocker]

Tonight's anomalies all singing from the same hymn sheet that the Atlantic express is running to schedule.

 

Trough eastern Pacific, HP NE North America, a weak trough off SE US that could be the spawning ground for troughs to join the split jet exiting the US  NOAA 6-10 has the trough firmly established north of the UK as have the others with perhaps not so much emphasis. HP to the east in northern Europe.

 

So surface analysis is pretty familiar with low pressure the NW/N and HP to the south giving the usual transitions between systems in the UK. Temps generally below average but periods above, particularly further south.

 

Charts courtesy weatherbell

 

[Captain Shortwave]

Currently we still can't seem to shake the polar vortex lobe over Greenland, but as the ECM shows we can still get some seasonal weather if we end up with a deep trough through Europe. A chilly north westerly develops after the potential gales during the middle of next week. Wintry showers in the west and mostly sunny skies further east as showers fade as they track across land. The ensembles seem to back this chilly set up with temperatures across the north sea sitting in middle single figures, probably similar for us. 

Some twitching about potentially developing a new lobe towards Eastern Siberia towards the end of week 2, but a long way off for now.

[bluearmy]

Would love to see the control run, it falls off the cold cliff

is that an easterly I wonder?

 

 

pluim_06260_0_12_60.png

 

 

It seems very similar to the Op up to day 10 as well

It's not an easterly as you'd like to see it. Continental flow around a s euro trough. mobile run throughout with Atlantic ridge occasionally joining with blocking to our east and then depressions dropping in and sinking.

[Cloud 10]

We don't have the parallel pub run for a few days,but the normal 18z is a touch more amplified and showing a pretty chilly end to the weekend.