Model Output Discussion 1200 hrs 15/11/14

[MR EXTREMES]

look at the difference ukmo and gfs same time frame its rather strange massive heights cutting in the other side of the pole but nothing on the gfs????

be inclined to think the gfs is wrong.

[Mapantz]

Day 7 is a million times better on the 12z, this block is never going to die!

 

 

GFS P 12z is also looking much better

 

 

Chalk and Cheese from the 06z really, Atlantic dominance is being pushed back further into FI!

By a few hours, maybe?

It is looking decidedly wetter as we get towards the back end of the month.

[Barry12]

By a few hours, maybe?

Screenshots_2014-11-21-16-32-12.png

It is looking decidedly wetter as we get towards the back end of the month.

 

I'm Looking at the whole NH not just the surface conditions to the UK. If you think the 06z and 12z are similar, then your not looking at the same models as me!

[ItNeverSnowsInWindsor]

Bin the GFS 12z output after T240 as it just removes the Scandi high with ease in the lower resolution output!

[Nick F]

Very strong jet stream emerging out of N America later next week and heading toward SW Europe looking at 12z GFS, very much as a consequence of another very cold arctic blast dropping SE across central Canada towards eastern US which steepens the thermal gradient along the eastern seaboard. Thank goodness, unlike last late November, that we have a strong block just to our east keeping the strong jet diving SE away from the UK!

 

 

There were actually some large disagreements between ECM and GFS yesterday upstream from both 00z and 12z runs wrt to another arctic cold pool dropping down across N America next week, GFS had it dropping SE into Ern USA while ECM had it dropping across central USA. This morning's ECM op had backed down and joined GFS which has stubbornly stuck with the eastern option. i think that's why today's 00z ECM was displaying alot more Atlantic mobility near the UK than previous runs, simply because the cold pool is further east across N America than advertised yesterday.

 

Not often ECM abandons ship and jumps on board with GFS, but just goes to show the volatility of the upper pattern upstream and perhaps a sign that the lobes of the Polar Vortex and the PV itself are rather unstable this winter, due to the constant pounding from wavenumbers 1 and 2 this late autumn. The models may have more mares to come this winter with the unstable PV ... it won't be plain sailing for medium range forecasters either!

Edited November 21, 2014 by Nick F

[shaky]

Crazy output this evening! ! Scandi high back with a vengeance!! The difference from the o6 to the 12z is ridiculous! !! All am saying is ukmo looks just as good as the gfs and when that is the case you must feel a whole lot better cos normally its the ukmo that doesnt show these synoptics and it's right 70% of the time!!very important to have ukmo on board at the moment! !

[Barry12]

Surprising 12z runs today, far better than this mornings runs, heres the UKMO 12z and 0z for comparison:

 

 

The continent is cooling down rapidly as well:

 

 

Now we just need the ECM to come on board...

Edited November 21, 2014 by Barry95

[mushymanrob]

i wouldnt take much notice of the odd models variation, the trend is still for the block to slowly give way. of course thats been expected for a while now and hasnt happened, but the models do still suggest the atlantic will 'win' out, even if all it does is shift the battleground eastwards.

[Barry12]

i wouldnt take much notice of the odd models variation, the trend is still for the block to slowly give way. of course thats been expected for a while now and hasnt happened, but the models do still suggest the atlantic will 'win' out, even if all it does is shift the battleground eastwards.

 

At day 7 the block is still very strong, any 'trends' of the block giving way is well into FI:

 

 

The Jet is also diving well south

[knocker]

Day 7 is a million times better on the 12z, this block is never going to die!

 

 

 

GFS P 12z is also looking much better

 

 

 

Chalk and Cheese from the 06z really, Atlantic dominance is being pushed back further into FI!

 

Maybe but I did hear a whisper that the last rites were being read against the whistle in the background of a 200kt jet.

Edited November 21, 2014 by knocker

[Snowy L]

i wouldnt take much notice of the odd models variation, the trend is still for the block to slowly give way. of course thats been expected for a while now and hasnt happened, but the models do still suggest the atlantic will 'win' out, even if all it does is shift the battleground eastwards.

 

The trend that sees the block fade away always starts at 240+ as soon as we get into the low res.

[BLAST FROM THE PAST]

Negatives - so far re cold, a lot of the runs aren't cold friendly generally today

Positives - still we see the jet diving SE, the GFS differences at reasonable short range hemispherically run to run, and the UKMO 12z is pretty ok I'd say and for me holds the day to the point that this is far from settled. 

 

There is quite a bit more consistency required for a cold or mild outlook.  I think the model watching  stakes are starting to ramp up.

 

In reality the point of action one way or another is still FI model wise......and the block isn't removed until its actually removed?

 

BFTP 

Edited November 21, 2014 by BLAST FROM THE PAST

[johnholmes]

Negatives - so far re cold, a lot of the runs aren't cold friendly generally today

Positives - still we see the jet diving SE, the GFS differences at reasonable short range hemispherically run to run, and the UKMO 12z is pretty ok I'd say and for me holds the day to the point that this is far from settled.  There is quite a bit more consistency required for a cold or mild outlook.  I think the model watching  stakes are starting to ramp up.

 

BFTP 

 

one has to admire your optimism, if you are a cold lover, BFTP.

There is absolutely no sign of anything developing in the next 2 weeks that would give cold to this country. Well that is my view and I have been wrong before!

[BLAST FROM THE PAST]

The trend that sees the block fade away always starts at 240+ as soon as we get into the low res.

Is that a trend?  The GFS almost always goes into pile the block away in deep FI

 

BFTP

[BLAST FROM THE PAST]

one has to admire your optimism, if you are a cold lover, BFTP.

There is absolutely no sign of anything developing in the next 2 weeks that would give cold to this country. Well that is my view and I have been wrong before!

Everyone has John and sometimes fairly often compared to yourself [sincerely stated], but the models are rather poor at times but why is there absolutely no sign of anything developing in next two weeks to bring cold?

I'm not expecting any deep cold or snow at all this month let's make that clear as it doesn't really happen overnight, but I am looking for developments backend of this month of colder weather pattern being present that may bring much colder weather in early December.   Just want to make it clear

 

 

I'll take this for today

 

 

 

BFTP

Edited November 21, 2014 by BLAST FROM THE PAST

[Tim Bland]

I don't share the optimism of others when the "block" is maintained. As per the latest GFS, the "Block" is over scandi and the Atlantic is driving mild wet weather at the UK. Unless we see retrogression towards Iceland / Greenland it is no use to us in providing cold. A terrible start to the season IMO. No eye candy runs so far, not even the odd ensemble to drag out! Hopefully it's just a slow start and things improve mid December

[swfc]

I don't share the optimism of others when the "block" is maintained. As per the latest GFS, the "Block" is over scandi and the Atlantic is driving mild wet weather at the UK. Unless we see retrogression towards Iceland / Greenland it is no use to us in providing cold. A terrible start to the season IMO. No eye candy runs so far, not even the odd ensemble to drag out! Hopefully it's just a slow start and things improve mid December

Start to the season??Its still november!!Last weekend ecm and gfs were showing retrogression and incredible nh blocking and pv distruption.Its changed but maybe in a week or so given the strat conditions it may swing back,who nos?I think most would agree 7 days is a lifetime on the mo thread so id hold fire imo

Edited November 21, 2014 by swfc

[bluearmy]

whilst some are seeing the atlantic beginning to win the battle, i am seeing the opposite. the 00z NAEFS was positive re the slow route to cold and the 12z GEFS are singing the same tune. note the slow movement of the siberian vortex further east as the siberian high comes more to the fore in its inexorable push towards europe and scandinavia. more energy headed into the med on the 12z gefs which may finally break the sceuro ridges connection with the high heights way to our south.

 

i would like to see the ecm extended ens begin to show some better anomolys in this regard but post day 10, the drop off in resolution on the ecm ens does show when things are on the move somewhat. what cannot be ignored is the strength of the atlantic jet. i would be surprised to see the battle won quickly from the east but i do expect, as others, that it will be. whether that takes two weeks or longer, who knows - but i am fairly sure that the siberian high will not be held back this winter.

I don't share the optimism of others when the "block" is maintained. As per the latest GFS, the "Block" is over scandi and the Atlantic is driving mild wet weather at the UK. Unless we see retrogression towards Iceland / Greenland it is no use to us in providing cold. A terrible start to the season IMO. No eye candy runs so far, not even the odd ensemble to drag out! Hopefully it's just a slow start and things improve mid December

 

no 9 tim. tbh,  hemispherically speaking, the last couple days have provided some decent runs again and i note the NOAA AO graph trending back neutral/negative today.

[Man With Beard]

And so the battle goes on. UKMO T144 nearly splits the PV, and ECM T192 has the Scandi ridge all the way back to Greenland. Its the end of November and the PV still is being whacked around. I wonder if this pattern has been set for the winter? I'm also sensing some people wanting the Scandi ridge to crash now - personally, I'd keep it, its only to lead to a colder and colder pattern as we get deeper and deeper into winter and will eventually leave us just one well directed slider low away from the freezer.

[nick sussex]

Oh no another ECM wild goose chase! Gone is this mornings horror show to be replaced by a stronger high to the east and the trough splitting.

 

There was a cluster of more easterly wind ECM ensembles this morning so perhaps its gone with one of those but overall I have little confidence in any of the outputs , the ECM in particular .

[swfc]

Better ecm here with the block further west!!!Things ae so fluid atm and very much up in the air .Not much in the way of a move north in the block but its staying fairly strong

[Barry12]

Certainly not a bad position to be in as we start Winter

 

 

slight push west from the Scandi high and we'd be in an Easterly flow. (Yes, I know it's day 10)

[mushymanrob]

The trend that sees the block fade away always starts at 240+ as soon as we get into the low res.

Well it doesn't actually as the charts barry95 displays show. And they are in line with what i posted that the block is expected to slowly decline, which senior forecasters have predicted.

Of course it might not go according to current expectations. But placing hopes on odd runs without further support from the more knowledgeable is not a wise move imho.

[Cloud 10]

Oh no another ECM wild goose chase! Gone is this mornings horror show to be replaced by a stronger high to the east and the trough splitting.

 

There was a cluster of more easterly wind ECM ensembles this morning so perhaps its gone with one of those but overall I have little confidence in any of the outputs , the ECM in particular .

 

The JMA at day 8 looks in the same ballpark as the ECM,although that doesn't exactly inspire confidence!

 

[nick sussex]

So far this evening the ECM and JMA are best for cold potential. The GFS P is like the ECM 00hrs with the PV looking ominous to the north, the GEM in between, the UKMO is really out of kilter with any other output and looks to be an outlier solution.the GFS tries to split the trough but upstream phasing negates that.

 

Even if the ECM had some deep cold to draw on from the east it still would be Code Red,  I prefer the JMA solution as high pressure there is already better placed to the north to exert better forcing on the troughing.

 

The interest really is whether those ECM ensembles stick with that easterly cluster and how many actually bring a cold pool further west.

 

After this mornings ECM somewhat relieved to see it drop that hideous run but its hard to have too much faith in any of the outputs because of these wild swings.

 

NCEP have basically written a book this evening on the uncertainty, below is just a small part!

 

...OVERVIEW...

GUIDANCE IS CONTINUING TO INDICATE THAT A SIGNIFICANT AMOUNT OF
FCST UNCERTAINTY WILL ORIGINATE FROM THE ERN PACIFIC.  THERE ARE
STILL MEANINGFUL DIFFS IN HOW FLOW WITHIN THE TROUGH NEAR 150W
WILL SEPARATE AROUND DAY 4 TUE... WHICH IMPACTS DOWNSTREAM DETAILS
THEREAFTER... ALONG WITH HOW UPSTREAM NRN PAC ENERGY WILL INTERACT
WITH THE UPR LOW/TROUGH THAT IS LEFT BEHIND AFTER THE SEPARATION
OCCURS.  THUS FCST CONFIDENCE DECREASES FAIRLY RAPIDLY AFTER
REASONABLE AGREEMENT AMONG SOLNS INTO TUE.  TRENDS THAT ARE
EVIDENT OVER THE PAST DAY ARE SUGGESTING SOMEWHAT LONGER
PERSISTENCE OF THE WEST COAST RIDGE/ERN CONUS TROUGH MEAN PATTERN.

 

The full discussion can be found here:

 

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

Edited November 21, 2014 by nick sussex