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Model output discussion - 20th Feb onwards

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6 minutes ago, fergieweather said:

Spot different directions again between 00z EC Operational and EC-P.... (Reading shown)

 

Screenshot_2016-02-25-10-37-11-1.png

Screenshot_2016-02-25-10-37-03-1.png

So it that showing the parallel op and control much colder?, do we know whether its definitely more accurate yet or not?

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The GFS 6z continues to show cold N/W Pm shots into the run, With a cold dry Easterly flow into the last few frames as Lows track further South.

a.pngb.pngc.png

Edited by Polar Maritime

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3 minutes ago, feb1991blizzard said:

So it that showing the parallel op and control much colder?, do we know whether its definitely more accurate yet or not?

The bottom (9km) is the parallel version due to replace current 16km model. It has been verifying very well. I recall it's due to become operational in April, but will check.

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17 minutes ago, fergieweather said:

Spot different directions again between 00z EC Operational and EC-P.... (Reading shown)

 

Screenshot_2016-02-25-10-37-11-1.png

Screenshot_2016-02-25-10-37-03-1.png

 

Is the EC-P the upgraded ECMWF op that's scheduled to go live in March?

 

Edit: Oh, already answered. :)

 

Edited by Yarmy

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Re: ECM parallel stats. Ryan Maue tweeted some here a week or so ago.

 

Very impressive, but it's noticeable that the bad days tend to coincide between the big hitters. Always something to remember when we get cross-model agreement.

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6 minutes ago, Yarmy said:

Re: ECM parallel stats. Ryan Maue tweeted some here a week or so ago.

 

Very impressive, but it's noticeable that the bad days tend to coincide between the big hitters. Always something to remember when we get cross-model agreement.

(First post!) Very interesting the above Yarmy. I wonder what the error margins are though, given low (n=136) sample number and frequently small differences between the models?

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6 minutes ago, Sijmen said:

(First post!) Very interesting the above Yarmy. I wonder what the error margins are though, given low (n=136) sample number and frequently small differences between the models?

n=136 is 2 runs a day for approximately 2 months, I suppose, but it may have been running for a lot longer than that. Presumably the have plenty of other metrics to look at too.

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1 hour ago, fergieweather said:

Spot different directions again between 00z EC Operational and EC-P.... (Reading shown)

 

Screenshot_2016-02-25-10-37-11-1.png

Screenshot_2016-02-25-10-37-03-1.png

So the current op is a warm outlier, and the parallel is a cold outlier!! The ensemble clustering not really representative of either. So should we be wary of outputs for D8 onwards??

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Quite Ian, that is key. Are there plans further down the line to increase resolution even further as computing power and data allows?

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55 minutes ago, Yarmy said:

 

Is the EC-P the upgraded ECMWF op that's scheduled to go live in March?

 

Edit: Oh, already answered. :)

 

It's still March 8th according to WxBell unless it's been changed recently. Some detail if it's of interest.

ECMWF plans to upgrade the horizontal resolution of its analyses and forecasts.The upgrade will have a horizontal resolution that translates to about 9 km for HRES and the data assimilation (the outer loop of the 4D-Var) and to about 18 km for the ENS up to day 15. The resolution of the ENS extended (day 16 up to day 46) will be about 36 km.

A new cycle of the IFS will be introduced to implement the horizontal resolution upgrade. This cycle is labelled 41r2 and includes a number of enhancements to the model and data assimilation listed herein. The detailed specification of the resolution upgrades included in IFS cycle 41r2 are:

Introduction of a new form of the reduced Gaussian grid, the octahedral grid, for HRES, ENS and ENS Extended;

Horizontal resolution of the HRES increased from TL1279 / N640 to TCO1279 / O1280, where subscript C stands for cubic and O for octahedral;

Horizontal resolution of the ENS increased from TL639 / N320 to TCO639 / O640 for ENS (Days 0 - 15) and from TL319 / N160 to TCO319 / O320  for ENS Extended (Days 16 - 46);

For the medium-range ENS there will no longer be a decrease of resolution at day 10: the ENS Days 11 - 15 will be run at the same TCO639 / O640 resolution as ENS Days 0 - 10;

Increase of the HRES-WAM resolution from 0.25 to 0.125 degrees and the ENS-WAM Days 0 - 15 from  0.5 to 0.25 degrees;

Horizontal resolution of the EDA outer loop is increased from TL399 to TCO639 with its two inner loops increased from TL159 / TL159 to TL191 / TL191, respectively;

Horizontal resolution of the three 4DVar inner loops is increased from TL255 / TL255 / TL255 to TL255 / TL319 / TL399, respectively.

These upgrades

do not include any increase in the vertical resolution;

do not apply to the ECMWF seasonal forecasting system;

do not apply to the standalone wave model (HRES-SAW);

do apply to products from the Boundary Condition Optional Programme.

Edited by knocker

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2 hours ago, johnholmes said:

nor do I see any N or NE flow other than transient behind a surface feature. The outputs this morning show ECMWF still suggesting a somewhat flatter flow than either NOAA or GFS in the anomaly charts but overall little major change in pattern in the upper air seems likely for 10-14 days to me.

John / Mushy - would welcome a little more detail on your thoughts. We're particularly discussing the NOAA chart here:

814day.03.gif

The upward kink in the lines towards Iceland indicates a tendency for higher pressure, from the Azores all the way up to the Iceland/Greenland area. The downward kink in the lines from Norway to Italy indicates a tendency for lower pressure. I have to conclude that this higher pressure in the Atlantic will mean that, as a mean over the 8-14 day period, we would expect winds to come from a northerly direction on their path to the UK. Not an Arctic northerly, but originating from the north. Now this could be a combination of N/NNW/NWlys on some days and variant directions as troughs emerge through the flow dropping from the north down to mainland Europe. And, if a trough does drop into mainland Europe, there is likely to be a period, even short, where winds veer back NEly. 

John/Mushy - is there a flaw in my argument?

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2 hours ago, feb1991blizzard said:

The GFS 6z is looking like a stonker, just a question to those that use the anomaly charts, there is a scandi block that looks like sitting there for a good few days (we will see in a few minutes), is this only another way of representing the information, surely the next GFS anomaly chart should show a scandi block??

the noaa charts dont show a scandi block, most of the gfs 06z is unlikely to occur according to the noaa's, the 06z gfs looks to be in agreement @ 162 and right at the end @384 . i dont know whether the  gfs anomaly will show this or why it doesnt if it doesnt. ill keep things simple and stick with the noaa's.

56 minutes ago, Man With Beard said:

John / Mushy - would welcome a little more detail on your thoughts. We're particularly discussing the NOAA chart here:

814day.03.gif

The upward kink in the lines towards Iceland indicates a tendency for higher pressure, from the Azores all the way up to the Iceland/Greenland area. The downward kink in the lines from Norway to Italy indicates a tendency for lower pressure. I have to conclude that this higher pressure in the Atlantic will mean that, as a mean over the 8-14 day period, we would expect winds to come from a northerly direction on their path to the UK. Not an Arctic northerly, but originating from the north. Now this could be a combination of N/NNW/NWlys on some days and variant directions as troughs emerge through the flow dropping from the north down to mainland Europe. And, if a trough does drop into mainland Europe, there is likely to be a period, even short, where winds veer back NEly. 

John/Mushy - is there a flaw in my argument?

yep, theres a strong azores high, and a  scandinavian trough. if you view the green lines, they represent the direction of the upper air flow which over the uk on that chart is northwest. surface features, systems , shortwave lows, are likely to track towards the southeast from the northwest. in front of these features the surface winds would come from a more southerly, or south of northwest. behind the feature surface winds would indeed come from the north or northeast. but these arent fixed, they are transient as the upper flow (mean) remains in the northwest.

there would indeed be a lot of polar maritime air in this pattern. :)

im sure john holmes will be able to explain it better then i..

 

heres a chart id expect to verify off the current noaa 8-14 day.

56cef86ed6647_likethis.thumb.gif.621fa71

Edited by mushymanrob
added charts

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15 minutes ago, mushymanrob said:

the noaa charts dont show a scandi block, most of the gfs 06z is unlikely to occur according to the noaa's, the 06z gfs looks to be in agreement @ 162 and right at the end @384 . i dont know whether the  gfs anomaly will show this or why it doesnt if it doesnt. ill keep things simple and stick with the noaa's.

yep, theres a strong azores high, and a  scandinavian trough. if you view the green lines, they represent the direction of the upper air flow which over the uk on that chart is northwest. surface features, systems , shortwave lows, are likely to track towards the southeast from the northwest. in front of these features the surface winds would come from a more southerly, or south of northwest. behind the feature surface winds would indeed come from the north or northeast. but these arent fixed, they are transient as the upper flow (mean) remains in the northwest.

there would indeed be a lot of polar maritime air in this pattern. :)

im sure john holmes will be able to explain it better then i..

 

heres a chart id expect to verify off the current noaa 8-14 day.

56cef86ed6647_likethis.thumb.gif.621fa71

I think that a very fair assessment and John more or less covered it in an earlier post with, "nor do I see any N or NE flow other than transient behind a surface feature".

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33 minutes ago, mushymanrob said:

the noaa charts dont show a scandi block, most of the gfs 06z is unlikely to occur according to the noaa's, the 06z gfs looks to be in agreement @ 162 and right at the end @384 . i dont know whether the  gfs anomaly will show this or why it doesnt if it doesnt. ill keep things simple and stick with the noaa's.

yep, theres a strong azores high, and a  scandinavian trough. if you view the green lines, they represent the direction of the upper air flow which over the uk on that chart is northwest. surface features, systems , shortwave lows, are likely to track towards the southeast from the northwest. in front of these features the surface winds would come from a more southerly, or south of northwest. behind the feature surface winds would indeed come from the north or northeast. but these arent fixed, they are transient as the upper flow (mean) remains in the northwest.

there would indeed be a lot of polar maritime air in this pattern. :)

im sure john holmes will be able to explain it better then i..

 

heres a chart id expect to verify off the current noaa 8-14 day.

56cef86ed6647_likethis.thumb.gif.621fa71

A good few GEFS members going for screaming Northerlies with a stonking big greeny ridge at the end of the run.

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10 minutes ago, feb1991blizzard said:

A good few GEFS members going for screaming Northerlies with a stonking big greeny ridge at the end of the run.

But transient?

gefs_z500a_5d_nh_61.thumb.png.f37679276c

On the other hand the GEFs is tending to veer  the upper flow with increased amplification ridge/trough but this of course is not the same as the NOAA chart in question.

gefs_z500a_nh_61.thumb.png.f49b8f6ada912

 

Edited by knocker

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Just now, knocker said:

But transient?

gefs_z500a_5d_nh_61.thumb.png.f37679276c

The ridge looks quite persistent in longer range products. I note Joe B, Weather Company-WSI et al getting on this trend for W Europe via twitter (so what could possibly go wrong?) ;-) 

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Agree Knock, Only transient Northerlys as the Lows pass. Being more a N/W Pm flow on the whole..

Edited by Polar Maritime

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5 minutes ago, knocker said:

But transient?

gefs_z500a_5d_nh_61.thumb.png.f37679276c

Who knows, its right at the end of the run, not sure whether its the stratosphere finally having a 'proper' impact or not, lets see what happens on the 12z runs.

Edited by feb1991blizzard

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6 minutes ago, fergieweather said:

The ridge looks quite persistent in longer range products. I note Joe B, Weather Company-WSI et al getting on this trend for W Europe via twitter (so what could possibly go wrong?) ;-) 

Yes a good number of GEFS members do show what looks to me what would be persistent HLB, (obviously cant tell yet because its right at the end), not desperately cold uppers but cold enough to produce snow.

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Great to see those verification stats for the new ECM P.

Also thanks to Ian for sharing the ECM P op run which does go in a separate direction from the normal ECM. I'm wondering whether we're seeing some jumpiness to the differing views of the MJO.

The GEFS in particular are still keen to displace the Azores high and quite a few building high pressure to the n/nw. I think the issue at this time of year is how you inject enough cold into the circulation, you can't rely on cold pooling developing over the continent as you would see in the deeper winter months.

I've decided to refrain from throwing the towel in just yet, my key date will be the 8th March as that's the latest I've recorded an ice day here in sw France, that was in 2010 and that saw the 8th to the 11th with maxs -1, 4, 1,3. Remarkable for that late in the season, and also remarkable was how the snow held up even with that big increase in solar energy. The key thing is the dew point and of course with an east/ne flow here the landmass does help. But if I can get that here then why shouldn't the UK be able to get a decent spell.

Of course nothing much has gone right for the UK in terms of cold and snow this year and even when some on the face of it good synoptics have appeared theres been a lack of a decent cold pool.

I think its a case of seeing whether the models will continue to play around with some high pressure to the nw/n and whether a PV lobe can drop down south to the east/ne to inject some deep cold into the circulation.

 

 

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06z ensembles for London showing a brief warm up, although it won't be truly mild, then a return to below average. A late winter treat for having to endure so much mild muck. Leave it until after the end of astronomical winter to begin looking for warmth. :D

cAN5t8A.png

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for MWB and what you asked, mushy pretty much covered things really. Remember they are mean charts and they are for 500mb not the surface. The upper air pattern be it at 500mb or 300mb is largely what governs our weather patterns. There is a degree of chicken and egg quite often as to which is the most responsible for surface weather.

However, if you take an overall view that it is the upper pattern, in our neck of the woods, which largely creates the weather and the type of weather you will not usually be far off the mark. In the bit about 'mean' charts, that is a vital thing to remember, individual day to day variations will occur, quite neatly covered again by mushy when referring to wind directions ahead of and behind separate weather systems. What happens below 500mb is at times quite difficult to get right.

Decades ago before computer models we almost always struggled with detail out to 24 hours. The same is pretty much ture today and of course at further out times. One thing that has not changed and very likely accounts for the problems synoptic models have is that the physics behind meteorology, thermal dynamics in particular, is just the same in 2016 as in 1915 or 1015.

That is not to say that the climate has not changed, there is a difference. Sorry for waffling but please pm me if you want to chat more rather than me cluttering up the model thread. As most meteorologists, be they professional or amateur, I am always happy to discuss the subjext, probably ad nauseum!

 

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1 hour ago, feb1991blizzard said:

A good few GEFS members going for screaming Northerlies with a stonking big greeny ridge at the end of the run.

might change sir... the anomaly charts are only predicting with current data, and they dont suggest a huge greenland high (lasting) , but indeed they might change, but until they do, id have thought the chances of one were low?.  of course these charts are not 100% accurate, and on this occasion might have to adjust to something others have picked up on first.

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