Model output discussion pm 13/01/2016

[JOPRO]

3 minutes ago, Paul_1978 said:

Are we sure that the models have got a good handle on that sub-tropical storm yet? Storm Alex?

It's just that @fergieweatheralluded to it causing a blocked Atlantic and low pressure tracking south of the UK. Unless the picture has changed overnight and we hear any different today then it's something to keep an eye on. 

 

Can I also add that Ian has access to MOGREPS which has been absolutely rock solid in its outputs over the last few winters, when has he ever said it has done a GFS style flip??

[The Beast From The East]

So many different views and opinions on here this morning and that's what I like to see ,after all it is the model discussion thread. Great posts. 

[nick sussex]

I don't think this tropical storm is the issue. Its still absorbed quickly into the upstream troughing.  I think its had its moment in the sun!

[Matthew Gill]

Wind map seems prime for a Cheshire gap scenario later today. Might surprise a few people

[Gazza H]

Ok so as a new guy to this I've took on the advice of "wait until the cold kicks in" to let the models settle down and then come to easier conclusions. So now the cold's here I'm non the wiser, the three main models seem to have been thrown off by the tropical cyclone Alex?  Would I be correct in assuming that once this cyclone has passed up into Greenland, as predicted that model outputs should start to "settle" as such and be more of a close run thing? Cheers guys n Gals, I'm always lurching in the background learning massive amounts every day in here, keep up the great posts!

[Frosty.]

I would go as far as the T+120 fax chart which shows very cold air entrenched across the UK, it's a very good looking fax in this coldies opinion!!

[seaside 60]

That Fax chart makes a mockery of this mornings GFS run.
Those fronts are miles away from the SW.

Reading between the lines I suggest a gander at that and the Mets over view is pretty much the score until mon/tues.
 

[nick sussex]

The GFS 06hrs run slightly better at T60 hrs than the GFS 00hrs run less progressive.

Edited January 14, 2016 by nick sussex

[MR EXTREMES]

15 minutes ago, nick sussex said:

I don't think this tropical storm is the issue. Its still absorbed quickly into the upstream troughing.  I think its had its moment in the sun!

Interesting Nick you where concerned last night that you were not convinced I think if by tomorrow morning the ukmo and the rest are all singing praise the warm up then I will await another chance later in the month into Feb.

but as hard as it is to say this !

clearly the pv plus ex tropical storm is really a pain in the ass.

but just maybe as the ukmo model is our own model then maybe it has different data input that deals with Atlantic and our location Europe better than the rest maybe that's hope casting statement.

i really don't see why the ukmo can't be right the current blocking is not all that weak and I can't see the Atlantic getting to Far East I still think a Scandinavia high is going to form or our current high will drift north east maybe north in time.

but if the outputs are all in agreement tomorrow am I will await the next try for another taste of winter.

but the sun is shining fresh arctic polar air it's really rather refreshing.

perhaps mjo on the move I can't see as I'm on my mobile.

keep the faith there be more chances even into March April and knockers daffs look like hibernating for awhile yet.

i certainly don't see a December rerun anytime soon maybe we should see what falls out of the sky over the next few days.

some will be happy just to see frost and a wintry showers.

but it's been chaos for days from nearly all the models except the ukmo so all is not a done deal yet but the vortex does ramp up so I'm on the fence 

 

[Harsh Climate]

1 hour ago, nick sussex said:

Jeez what a poor turnaround in the outputs.

Even the undercut looks hard to achieve, after lauding the UKMO that's backtracked but still much better than the GFS/ECM.

The ECM ensembles are going the wrong way and that poor looking cluster last night seems to have grown, theres not even agreement now within T72hrs with the GFS most progressive.

Very bizarre goings on but it does look like the cold will have a difficult job hanging on given the GFS/ECM spill a lot more energy eastwards.

Its amazing just what a mess the models can make of undercutting scenarios, overall after a decent trend yesterday its all gone rather pearshaped so far today.

 

Yes you can't deny that the change in output overnight is simply dreadful. I'm not saying that's it game over for any good prolonged cold/snowy spell but we have just gone from 8/10 last night to 3/10 this morning. Back to the good old ''at least there's potential'' stage. 

Due to the models struggling like a fat lady trying to carry her shopping home, nothing is set in stone yet and I expect further developments but early next week we have now moved a fair bit away from the classic undercut snowfall scenario or an undercut drawing in a cold continental feed. I think It may be wise to just settle for the blocking high sitting on top of  us with cold remaining, then build from there.

Just out of interest nick, do you look at the charts in the same way as you do for the UK in hoping for cold and snow for were you live in south west france?? Often wondered this lol. If I am being honest If I lived in the south west of france I would be praying for the sinking high/all so close beasterly for the UK, with the low countries getting the easterly, deep cold and a pasting lol 

Edited January 14, 2016 by Harsh Climate

[Hammer]

GFS 6z corrections again as block modelled stronger. Just compare various time frames to see correction back West, less progressive.

An example look at 850's for previous run to this run and notice difference in about 100 miles or so for same time stamp. Still progressive. But a good indicator that nothing is totally certain.

Edited January 14, 2016 by Hammer

[bobbydog]

15 minutes ago, nick sussex said:

The GFS 06hrs run slightly better at T60 hrs than the GFS 00hrs run less progressive.

yes nick, the agony does seem slightly more prolonged on this run..

[nick sussex]

5 minutes ago, Harsh Climate said:

 

Yes you can't deny that the change in output overnight is simply dreadful. I'm not saying that's it game over for any good prolonged cold/snowy spell but we have just gone from 8/10 last night to 3/10 this morning. Back to the good old ''at least there's potential'' stage.

Due to the models struggling like a fat lady trying to carry her shopping home, nothing is set in stone yet and I expect further developments but early next week we have now moved a fair bit away from the classic undercut snowfall scenario or an undercut drawing in a cold continental feed. I think It may be wise to just settle for the blocking high sitting on top of  us with cold remaining, then build from there.

Just out of interest nick, do you look at the charts in the same way as you do for the UK in hoping for cold and snow for were you live in south west france?? Often wondered this lol. If I am being honest If I lived in the south west of france I would be praying for the sinking high/all so close beasterly for the UK, with the low countries getting the easterly, deep cold and a pasting lol 

Well that's a good question. Generally I don't mind too much down here as long as its on the cold side with no Euro high! I think because I suffered so much pain as a cold and snow lover in the UK that I always like to see good cold synoptics deliver there.

Generally even a good easterly for the UK would deliver here as the Genoa Low would normally pile in lots of instability in this part of France.

Although we might miss the really cold uppers we don't need that because of the lower dew points, its amazing the difference not having the North Sea can make!

Also I'm very fortunate to have the Pyrenees close by so wouldn't begrudge the UK getting its fair share of cold and snow.

Anyway in terms of the GFS 06hrs run its good to see it trend less progressive in the earlier stages, given how important these earlier timeframes are looking in this type of set up its a relief to see it pull back from the brink.

 

[bobbydog]

to he honest i would love the GFS to be spot on on this occasion, it shows monday's 'snow event' stalling and snowing for around 15 hours in the area indicated on the chart and stopping before it turns to rain!!

[karlos1983]

50 minutes ago, johnholmes said:

the link shows the predicted path of the storm from NOAA

http://www.nhc.noaa.gov/graphics_at1.shtml?5-daynl#contents

 

That is an interesting look as it relates to it's projected Track John. That screams to me that High pressure is certainly dominant to the east of it's track. If it wasn't then it would simply interact with the Jet and track east towards NW Europe.

Some fairly downbeat posts in here this morning which is not surprising, but I would say take a look at all 3 outputs this morning (GFS/ECM/UKMO), and you can see that there is disagreement very early. To my eyes the UKMO has certainly taken a step back from sending energy sliding under the block if you look all the way out to +144, but it is still cold. The +120 chart is loaded with potential though, and you can still see how that could produce an undercut, and an undercut that would be far more substantial than was shown on the 12z from yesterday.

That is very almost a BOOM chart.

The GFS is nothing like it, with the Atlantic back up and running and firing Low pressure straight towards us or just to our north. with a similar outcome from the ECM at the same timeframe, although it does show slightly higher heights to our North than the GFS.

My summary, although at face value it does have the look of a downgrade overnight and you could put a good argument forward for that, I won't be making my mind up until this afternoons 12z and that's presuming they all agree within a reasonable timeframe.

The UMKO at 120 is my chart of the week! (for fun flick between +96 and +120, looks like the heights want to retrogress NW?)

Cheers 

 

 

[Iceberg]

The tropical storm is still a factor, not least because they expect the tropical charecteristics to remain for longer i.e more and longer embedded TM air. Also due to the energy (this is certain to become a sub-tropical hurricane imho and probably is already as NHC are kind of saying).

But for me the most important fact is the 70% chance of a further systems behind it (maybe 24 hrs behind). this prolongs the moisture, heat and waa, currently no models are forcasting a secondary follow on sub tropical storm, but NHC have just updated to give one a 70% chance.

Its all more uncertains into the mix. I am saying they increase or decrease the chances of cold weather, but they will certainly effect model progression.

[karlos1983]

8 minutes ago, Iceberg said:

The tropical storm is still a factor, not least because they expect the tropical charecteristics to remain for longer i.e more and longer embedded TM air. Also due to the energy (this is certain to become a sub-tropical hurricane imho and probably is already as NHC are kind of saying).

But for me the most important fact is the 70% chance of a further systems behind it (maybe 24 hrs behind). this prolongs the moisture, heat and waa, currently no models are forcasting a secondary follow on sub tropical storm, but NHC have just updated to give one a 70% chance.

Its all more uncertains into the mix. I am saying they increase or decrease the chances of cold weather, but they will certainly effect model progression.

Agreed Iceberg, they surely cause havoc with the models because they aren't expected to be encountered at this time of year are they?

Edited January 14, 2016 by karlos1983

[Bristawl Si]

Mixed signals and considerable 'scatter' from midweek next week, according to Ian F latest.

I wouldnt get too hung up on period post next Monday. Models in state of confusion it seems.

[Froze were the Days]

Almost getting quite tiring now - after 'the trend is your friend' towards heights to the north/north west and the possibility of undercutting to the south west the trend seems now to be going back the other way and this is now even showing on the pace setter UKMO, whatever happens next this certainly has become protracted.

Have to say disappointed with the outputs this morning.

[Iceberg]

The ability for Alex to maintain its tropical core is crucial to how it will effect the models, as this will determine how much warm air is maintained. I assume that Alex will quickly lose the warm air once it opens up and starts to mix with its surroundings.

How quickly the transistion occurs is massively unknown, it could unwind in the next few hours, or stay in place for 24-48 hrs. All unknowns.

TBH its rare to have one of these no matter what the season, even in September !

[Spah1]

16 minutes ago, Bristle boy said:

Mixed signals and considerable 'scatter' from midweek next week, according to Ian F latest.

I wouldnt get too hung up on period post next Monday. Models in state of confusion it seems.

Where did you read that?

[karlos1983]

2 minutes ago, Spah1 said:

Where did you read that?

in our regional thread 

 

 

[Bristawl Si]

4 minutes ago, Spah1 said:

Where did you read that?

The clue is in my location.

[nick sussex]

Good grief whats going on!

Theres a marked difference between the GEFS 00hrs at T114hrs and the new GEFS 06hrs at T108hrs. A lot more keep high pressure to the north.

This is the GEFS 00hrs ensemble mean at T114hrs on the left and the GEFS 06hrs to T108hrs on the right:

If you look at each ensemble member then the difference is more marked in terms of the big jump in members keeping the high to the north.

The models seem to be making a lot of drama over the early timeframe, we should bear in mind this volatility could still go the wrong way in terms of the outlook because it doesn't give you much confidence when theres these big switches in ensembles within the normally more reliable timeframe.

 

Edited January 14, 2016 by nick sussex

[karlos1983]

3 minutes ago, nick sussex said:

Good grief whats going on!

Theres a marked difference between the GEFS 00hrs at T114hrs and the new GEFS 06hrs at T108hrs. A lot more keep high pressure to the north.

Ohhwah, I'm now going to have to scrape myself up off the floor and look. This better be good Nick lol