Model Output Discussion - 28th November - 4th December

[Grimsby Snow Lover]

Agreed, the Atlantic high is further west allowing a more northerly flow compaired with previous runs of today. Reminds me of charts from a few days back.

[kold weather]

A more cyclonic northerly from the 18z this time with the LP slower to clear, probably better chances for snow showers over E.Scotland and the NE of England on this run where pressure is lower.

[Matty M]

A more cyclonic northerly from the 18z this time with the LP slower to clear, probably better chances for snow showers over E.Scotland and the NE of England on this run where pressure is lower.

We just need the ridge to move in over Scandy and that low to swing SW hah.

[damianslaw]

GFS and UKMO show a similiar pattern for the end of the week i.e. ridging of azores high northwards linking tentatively with rising pressure over greenland - this ridge then building nicely over the country during the weekend. ECM not keen on this idea.. have a feeling it will fall in line with GFS/UKMO tomorrow.

Interesting to see GFS continues to paint a blocked pattern mid month. Remains to be seen whether this pattern will verify - I would be more confident in it if ECM was suggesting such a pattern as it tends to do much better than GFS when it comes to blocking to our east, conversely GFS tends to outperform ECM when it comes to developments to our west/northwest.. I wonder who has it right?

Edited December 4, 2011 by damianslaw

[DAVID SNOW]

Well the 18z is nicer at this point.

Could see a raw easterly thrown up here by the latter stages of this GFS18RUN

[kold weather]

I suspect the 18z will show abit of a sinker this run, jet profile doesn't look as good. Still the GFS keeps trying to produce a high in the Atlantic and take it over NW Europe, not a bad trend I suppose.

[legritter]

even all ,i said i would post a seriouse post ,but my computer is up the creek again . i honestly think that by this time next week we will have a seriouse high around but where it sits and which way it orientates wont become clear until the human produced chart next thurs is produced , and at the same time as some interesting synoptics take place either over us or near us , .we could be better off this winter having a PV about the half way house ,perhaps that could give some of us normal frontal events spread over the winter ,not squeezed into 3/4 weeks . i think at the moment im going with the met . i will try and post that other post again if i find it , cheers legritter

[BLAST FROM THE PAST]

Ok, it looks very much that the models are bringing a NW/SE axis over the UK. A colder set up than the, much vaunted by some, flat jet. I also think that there's more to come and I have an issue with the AZH and any linkage or build up of heights to our NE during this month. For me its too early and too much energy and the main Block from Siberia/ E Finland remains east. I think the programming of an 'elevated' ridge to our west linking with Greenland is the main potential player for the route to cold. In stratos thread and on record with Chiono, I stated I think any main cold shot will come for 3rd week of this month if it arrives...thats the week starting from midmonth but cold setup should prepare itself before then ie practice run?. I think N to NNW'ly is the route to cold with mid Atlantic block/ridge. It won't get entrenched IMO [if indeed it arrives ] as we revert to mild Christmas/following week towards New Year BUT kitchen sink and snow IMO at low levels for the south is possible latter part of this period

I think any riddance of the stronger heights to the NE scenario by any model down the line may be the one on the money and the GFS toys with the idea but IMO is too weak with the ridge holding its place down the line.

BFTP

Edited December 4, 2011 by BLAST FROM THE PAST

[Zakos]

GFS FI is a like a horror show for coldies. Good thing it is FI. A fairly significant upgrade to Fridays cold spell. Hope this upgrade trend continues.

I think the most likely FI to verify is the 12z. Suites me fine. An easterly/south easterly could crop up at any time in that pattern, with the potential to produce snow. I invariably get more snow from easterlies than northerlies in my area, so this is my personal opinion.

Edited December 4, 2011 by Zakos

[Severe Siberian icy blast]

Evening all , im stunned to be honest , iv just looked at all the models, the fax i looked at last , the 120hr chart looks very wintery, high pressure over greenland , which i then tracked back closer to date and was shocked to see it there all wk and moving into a much more favorable position as the wk closes, but firstly ,

Why has nobody mentioned it? And secondly. .

Is it not the most reliable when we get into short range?

It really doesnt look like the high will sit over us if anythin it looks to build in strength over to the northwest, Is that not the chart with the human input also?

Maybe im barking up the wrong tree and would welcome opinions, thanks folks .

[kold weather]

18z GFS FI is indeed painful and much more progressive than the 12z. It tries to develop a block but the jet and PV is that bit more agressive on this run. It is quite a plauseable solution as well, especially given the state of the stratosphere and PV at the moment that we see a more typical zonal spell occur.

[nick sussex]

Well the GFS is certainly being consistent with its view, no sign at all of it backtracking to the Euros on the 18hrs run.

The latest UKMO fax chart for 120hrs is a carbon copy of the raw output, it actually looks promising but will probably change again by tomorrow!

http://www.meteociel.fr/modeles/ukmo2.php?ech=120&carte=2000

I would certainly recommend people read the evening update from NOAA, it's all very pertinent to the downstream pattern in Europe.

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

To pick a few quotes out of there:

A HUGE RIDGE IN THE NE PACIFIC WHOSE CORE OF POSITIVE HEIGHT

ANOMALIES IS CENTERED VICINITY OF 55N/140N WILL BE THE DOMINANT

WEATHER CONTROLLER OVER NOAM DURING THE NEXT WEEK. THIS CORE OF

POSITIVE HEIGHT ANOMALIES IS IN A VERY SENSITIVE POSITION WITH

ONLY A SLIGHT WWD SHIFT FAVORING DOWNSTREAM ENERGY DROPPING S INTO

THE WRN CONUS. ON THE OTHER HAND ANY SEWD SHIFT OF THE CORE WILL

FAVOR THE ENERGY TOPPING THE RIDGE DROPPING MORE ESE INTO ERN

NOAM. ENSEMBLE SPAGHETTI PLOTS SHOW BOTH POSSIBILITIES WITH ABOVE

NORMAL SPREAD NEXT WEEKEND DAYS 5-7. THEY SHOW THE STRONG ERN

PACIFIC RIDGE TEMPORARILY BREAKING DOWN AROUND FRI DAY 6...THEN

REBUILDING NEXT SUN/MON DAYS 7-8.

12Z MODEL GUIDANCE IS STILL HAVING TIMING DIFFICULTIES IN

RESOLVING THE EVOLUTION OF A SHRTWV FCST TO CROSS THE ERN HALF OF

THE CONUS.

ALL MODELS...ALBEIT DETAIL DIFFERENCES...ARE TRYING BY DAY 7 TO

REESTABLISH SOME KIND OF MEAN TROF OVER THE WRN STATES DOWNSTREAM

OF A SHARP ERN PACIFIC RIDGE.

Those three I picked out will all have an impact in Europe both in the shorter and medium term.

[BLAST FROM THE PAST]

Evening all , im stunned to be honest , iv just looked at all the models, the fax i looked at last , the 120hr chart looks very wintery, high pressure over greenland , which i then tracked back closer to date and was shocked to see it there all wk and moving into a much more favorable position as the wk closes, but firstly ,

Why has nobody mentioned it? And secondly. .

Is it not the most reliable when we get into short range?

It really doesnt look like the high will sit over us if anythin it looks to build in strength over to the northwest, Is that not the chart with the human input also?

Maybe im barking up the wrong tree and would welcome opinions, thanks folks .

Absolutely, very good post and worth watching, been saying UKMO model cannot be ignored.

BFTP

[kold weather]

UKMO is rather close to an interesting set-up for the south. If you could get a slightly stronger cold drag, then the 144hrs chart probably would prove to be most interesting.

Anyway thread closing soon!!

Here is the new thread:

[WhiteFox]

Evening all , im stunned to be honest , iv just looked at all the models, the fax i looked at last , the 120hr chart looks very wintery, high pressure over greenland , which i then tracked back closer to date and was shocked to see it there all wk and moving into a much more favorable position as the wk closes, but firstly ,

Why has nobody mentioned it? And secondly. .

Probably because it's a transient surface high over Greenland. Look at the heights on the H500 chart:

Blues which indicate a surface high rather than the yellow and orange you'd see for a proper high which would block the appraoching low pressure systems.