Model output discussion - 20th Feb onwards

[mushymanrob]

1 hour ago, Frosty. said:

I do, and those Gfs 00z charts show wintry potential this morning with an increasingly blocked and colder further outlook and some polar maritime shots during the next week or so...Tuesday is the only mild day!

i didnt say otherwise mate... yes we will get some pm shots, but what will they deliver? look at now, today, we were supposed to be getting near ice days and snow showers off the north sea - what have we got?.. its a bit chilly.

the pm shots we are likely to get isnt anything unusual for the time of year, in early march its normal to get some chillier days with some wintry precipitation mostly on higher ground. so wintry with a small 'w', yep, normal - wintry as in like january?... nah, not on this mornings charts, just normal below average.

1 hour ago, weathernuts said:

However, it is supported by Glosea5, well at least it was a couple of days ago. Height rises to the N/W of the BI

i have no idea what glosea5 is. ive not viewed it, i dont even know where it is! imho theres so many resource facilities its hard to know what to pick and what to trust.  so for a layperson like myself who doesnt want to or have the time to delve much deeper, its simpler to find a favoured model and stick to that. so far the noaa charts are the most accurate for their timeframe (didnt i read somewhere that glosea5 was good at predicting blocking upto 3 month in advance?) . they have proven most accurate for the general picture time and time again, and when a few op runs predict something that the noaa charts dont support - its nearly a hundred percent that the noaa charts are proven right and the ops fantasy charts are inaccurate. this has happened many times this winter.

it would be interesting though if someone compared the accuracy of glosea5 against the noaa 500mb charts for the time period they cover.

Edited February 28, 2016 by mushymanrob
typo

[Tim Bland]

With temps hovering around freezing and low pressure / fronts around, at the end of the week I expect many of us will see snow falling. Settling may be reserved for high ground but it's better than what we have seen for most of this dire winter! 

[MR EXTREMES]

Certainly chilly but the lack of deep cold 850s still shows that northern areas will favorite for wintry weather perhaps Wales to.

all in all pretty disappointing for majority of the U.K. For snow fall.

looking forward to spring warmth rather spring cold .

[MR EXTREMES]

3 minutes ago, mushymanrob said:

i didnt say otherwise mate... yes we will get some pm shots, but what will they deliver? look at now, today, we were supposed to be getting near ice days and snow showers off the north sea - what have we got?.. its a bit chilly.

the pm shots we are likely to get isnt anything unusual for the time of year, in early march its normal to get some chillier days with some wintry precipitation mostly on higher ground. so wintry with a small 'w', yep, normal - wintry as in like january?... nah, not on this mornings charts, just normal below average.

i have no idea what glosea5 is. ive not viewed it, i dont even know where it is! imho theres so many resource facilities its hard to know what to pick and what to trust.  so for a layperson like myself who doesnt want to or have the time to delve much deeper, its simpler to find a favoured model and stick to that. so far the noaa charts are the most accurate for their timeframe (didnt i read somewhere that glosea5 was good at predicting blocking upto 3 month in advance?) . they have proven most accurate for the general picture time and time again, and when a few op runs predict something that the noaa charts dont support - its nearly a hundred percent that the noaa charts are proven right and the ops fantasy charts are inaccurate. this has happened many times this winter.

it would be interesting though if someone compared the accuracy of glosea5 against the noaa 500mb charts for the time period they cover.

Couldn't of put it better myself and agree it's nothing really exceptional 

[Banbury]

8 minutes ago, mushymanrob said:

i didnt say otherwise mate... yes we will get some pm shots, but what will they deliver? look at now, today, we were supposed to be getting near ice days and snow showers off the north sea - what have we got?.. its a bit chilly.

the pm shots we are likely to get isnt anything unusual for the time of year, in early march its normal to get some chillier days with some wintry precipitation mostly on higher ground. so wintry with a small 'w', yep, normal - wintry as in like january?... nah, not on this mornings charts, just normal below average.

i have no idea what glosea5 is. ive not viewed it, i dont even know where it is! imho theres so many resource facilities its hard to know what to pick and what to trust.  so for a layperson like myself who doesnt want to or have the time to delve much deeper, its simpler to find a favoured model and stick to that. so far the noaa charts are the most accurate for their timeframe (didnt i read somewhere that glosea5 was good at predicting blocking upto 3 month in advance?) . they have proven most accurate for the general picture time and time again, and when a few op runs predict something that the noaa charts dont support - its nearly a hundred percent that the noaa charts are proven right and the ops fantasy charts are inaccurate. this has happened many times this winter.

it would be interesting though if someone compared the accuracy of glosea5 against the noaa 500mb charts for the time period they cover.

Hang on a minute, who forecast "near ice days" ??? certainly wasn't the pro's , yes GFS might have shown it but thats GFS several days back.

[Polar Maritime]

I dont think anyone is stateing anything other than what the charts are showing, That is below avg temps/dry and 'wintry' at times especially for the North with some hard frosts. On the face of it quite a traditional start to Spring but colder than we have endured all Winter.

[Frosty.]

9 minutes ago, MR EXTREMES said:

it's nothing really exceptional 

I don't think anyone is suggesting it's an exceptional outlook showing on the models but it's certainly not looking like a mild early spring apart from Tuesday 1st March.

[knocker]

The latest from the woodshed

[feb1991blizzard]

1 minute ago, knocker said:

The latest from the woodshed

But take a look at some of the other CFS runs of late though, a good few show a temperature departure from the above in the negative direction.

[Midlands Ice Age]

35 minutes ago, mushymanrob said:

it would be interesting though if someone compared the accuracy of glosea5 against the noaa 500mb charts for the time period they cover.

Mushy

An interesting thought....

GLOSEA5  has been pretty accurate so far this year (according to IF).

The NOAA 500 mb have also been pretty good.

All this whilst the weather has been basically westerly driven during a winter dominated by the jet stream. Winds have generally moved from SSW in December, to westerly in January, to WNW in February. All this took 3 months to achieve. All this whilst the day to day models above 5 days have flip flopped all over the place.

Now in the past we have occasionally had very rapid switches in the weather patterns during periods of predominantly raging jet streams across the UK.

Has the NOAA been any good at picking this up, in the past??

GLOSEA5  has now started to point to more northerly blocking, whereas clearly you are forecasting much of the same.

It will be interesting to see which way, the trends go and will give us a better evaluation for the future.

MIA   

Edited February 28, 2016 by Midlands Ice Age

[Banbury]

13 minutes ago, Polar Maritime said:

I dont think anyone is stateing anything other than what the charts are showing, That is below avg temps/dry and 'wintry' at times especially for the North with some hard frosts. On the face of it quite a traditional start to Spring but colder than we have endured all Winter.

Again Friday is worth watching

[Gowon]

I know it's deep fi but with high pressure on both sides of the Atlantic and the Arctic yet still we can't get rid of those low heights around Greenland

[Cloud 10]

1 hour ago, Banbury said:

ECM and GFS very different at 216...................deep into FI of course

 

Should be noted that a strong (possibly record breaking) SSW is likely to occur around the 6-10 day timeframe,so could be some really whacky looking FI charts showing up soon.

 

[legritter]

3 hours ago, Timmytour said:

The models have been good this winter....unfortunately it's my hearing as I  get older that's been the problem.

So  many times I've though they were screaming out "there's snow potential!!" to me ......only to find out as they got closer was what they really calling out to me was "there's no potential"!

Fantastic post ,sums up winter for me too ,must get my ears syringed ready for next winters Model discussions ,here we are End of Meteorological winter and some good charts on offer today ,cheers .

[mushymanrob]

1 hour ago, Banbury said:

Hang on a minute, who forecast "near ice days" ??? certainly wasn't the pro's , yes GFS might have shown it but thats GFS several days back.

some of the cherry picked charts have done so, giving the impression that something like that will happen

yes, no ones posted what the charts havnt shown, but selecting only the coldest option, whilst not 'illegal' is misleading to those who want a realistic view of what might lie ahead.

48 minutes ago, Midlands Ice Age said:

Mushy

 

Has the NOAA been any good at picking this up, in the past??

GLOSEA5  has now started to point to more northerly blocking, whereas clearly you are forecasting much of the same.

It will be interesting to see which way, the trends go and will give us a better evaluation for the future.

MIA   

i can only report on what john holmes has found, as it was he who did the research. the rest of us (mostly) havnt done the research but have taken note of his observations and found them to be very good for the timeframe they cover.  if i remember correctly, john the other day suggested the 6-10 day chart is 70-80%  accurate whilst the 8-14 day is 60-70% ?... so the answer is that they are not perfect, and sometimes they can miss sudden swings. but compare their success rate at these time frames to the ecm and gfs that gibby publishes and youll see that the noaa are most accurate.

im not forecasting northern blocking, the current noaa charts suggest a strong azores ridge, nosing north of the azores with a trough in the north northsea . the 8-14 day chart suggests the azores ridge might drift closer to the uk, but the mean upper flow over the uk is still northwesterly. theres no strong northern blocking within the 6-14 day period on the current output, other then transient surface features.

but im a novice, i might be wrong!

[KyleHenry]

14 minutes ago, Cloud 10 said:

 

Should be noted that a strong (possibly record breaking) SSW is likely to occur around the 6-10 day timeframe,so could be some really whacky looking FI charts showing up soon.

 

Absolutely agree and until the SSW 2nd March to 6th March completes. There is no way that the models can get an exact grasp on the synoptical outcome just yet. 

 

Until the downwelling process and it's effects complete, then current outputs past these dates will show major swings. 

It will produce one key point and that is which model runs the best algorithms from the available data to get as close to actual outcome and be the first to do it.

Glosea5 has this crown overall. It will Interesting to see which public free to view model comes next. 

After SSW completes,  only then would I consider throwing in the towel for cold/ snow Synoptics. 

[Frosty.]

47 minutes ago, legritter said:

Fantastic post ,sums up winter for me too ,must get my ears syringed ready for next winters Model discussions ,here we are End of Meteorological winter and some good charts on offer today ,cheers .

Love your enthusiasm legritter, it's one of the reasons I have tried to keep spirits up this winter..

[johnholmes]

I would agree pretty much with what you have posted mushy.

If I could add, anomaly charts are fine for indicating, in their time scales of 6-10 for NOAA, ECMWF, GFS and then NOAA for 8-14, what the average upper air pattern is going to be, % accuracy from 3 years work on them and nothing since to suggest otherwise, much as mushy posts. This accuracy in both suggesting no major change from a current pattern AND showing a change in pattern of the upper air. This does allow a fair idea to be gained of will the surface air be sourced from Tm, Am or Pm or indeed their equivalents from land. Their time scale, from what I understand is much shorter than GLOSEA (someone correct me if this is not correct please?). It is also sensible to use them in conjunction with other teleconnections, MJO etc, and checking how the synoptic models AT THOSE TIME SCALES  are showing with CONSISTENCY. I know I go on about them but if you use them, or if you prefer read my inputs using them it will in at least 7 cases out of 10 days model outputs spare the 4 x ups and down from GFS and 2x from ECMWF. Of course a good many of you love the ups and downs the synoptic models provide so just use what you prefer. Remember also the anomaly charts are a MEAN type of chart which is why they do not flick about like the synoptic charts, so day to day the upper air pattern may not be as they show. This will only last 24 maybe 48 hours though before the synoptic pattern reverts back to the type the anomaly charts show.

Hopefully what I have posted will help some of you to have an understanding of what they can and cannot predict. The fine detail must always come from synoptic outputs. But remember post about 144 hours always compare like with like output that is 00z or 12z or whichever one you use, don't follow every run at time scales beyond this and expect much consistency much of the time. That said, since the various upgrades, GFS and ECMWF synoptic outputs have on several times in the last 12 months or so either equalled or even been ahead of changes suggested by the anomaly charts. I put this down to the various upgrades in these models. So in spite of a lot of teeth nashing by some there is an overall improvement, in the UPPER AIR patterns in the synoptic models. What is still to improve as much is the fine detail at the surface. In 40-50 years of meteorology this has always been the major stumbling block prior to computers and since their use. Things will improve I am sure in this aspect but don't expect major improvemsnts in short time scales.

sorry for the length of this post, not like me!

 

Edited February 28, 2016 by johnholmes

[Banbury]

43 minutes ago, mushymanrob said:

some of the cherry picked charts have done so, giving the impression that something like that will happen

yes, no ones posted what the charts havnt shown, but selecting only the coldest option, whilst not 'illegal' is misleading to those who want a realistic view of what might lie ahead.

i can only report on what john holmes has found, as it was he who did the research. the rest of us (mostly) havnt done the research but have taken note of his observations and found them to be very good for the timeframe they cover.  if i remember correctly, john the other day suggested the 6-10 day chart is 70-80%  accurate whilst the 8-14 day is 60-70% ?... so the answer is that they are not perfect, and sometimes they can miss sudden swings. but compare their success rate at these time frames to the ecm and gfs that gibby publishes and youll see that the noaa are most accurate.

im not forecasting northern blocking, the current noaa charts suggest a strong azores ridge, nosing north of the azores with a trough in the north northsea . the 8-14 day chart suggests the azores ridge might drift closer to the uk, but the mean upper flow over the uk is still northwesterly. theres no strong northern blocking within the 6-14 day period on the current output, other then transient surface features.

but im a novice, i might be wrong!

Yes but lets be fair Mush , the charts posted are Just For Fun , the real charts to take note of are on the Beeb, only and only when they mention ice days is the the time to take note,  we havent been close to those .......................yet

Edited February 28, 2016 by Banbury

[fergieweather]

3 hours ago, weathernuts said:

However, it is supported by Glosea5, well at least it was a couple of days ago. Height rises to the N/W of the BI

Latest GloSea output is consistent and still favours +ve MSLP rises in Arctic later March-early April. So, *overall* below average temperatures look likely across March. Somewhat nearer term, uncertainty days 10-13 re how far Atlantic ridge eases east to offer more settled flavour for a while, esp to NW. The general theme as March progresses is for colder than average conditions to be quite marked initially, but these to become more masked by wider diurnal swings through the month, with a gradual, erratic trend of temps creeping gradually back towards normal. With periods of renewed W/NW mobility running into colder air, snow is possible at times (northern uplands in particular). However, as many have repeatedly indicated, the expected situation is not comparable to the very extreme conditions that characterised March 2013...not that it's prevented some newspapers from much hyperbole re upcoming easter.

[phil nw.]

Just really something maybe to help newer members regarding mean outputs and anomaly charts discussed above.

If looking at the overall picture then as Mushy and John H have said the NOAA ht anomalies is as good as anything for us amateurs.

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

They do give an overall picture of the mean expected 500hPa pattern in the time frames shown -the green lines indicate the general upper flow or ridge/trough pattern across our side of the hemisphere.The red dashed lines show the -ve or+ve areas where the heights depart from climatology.

A look at the 2 images again the first is the mean spread across days 8-10 and the second days 8-14.

                                                                               

Clearly the overall pattern shows Atlantic ridging from the Azores high out west of the UK and a mean trough heading se into Europe just to our east.

If we look closely there is just a sign of the high out west moving a little closer with time but the overall north westerly outlook can be seen so temperatures on the colder side for the period would be a fair summary.Notice too in spite of the +ve hts across the Arctic that stubborn Canadian vortex is still hanging in there.

A look at some other ens outputs which i find useful are the ECM/NAEF's  suites-here's day 10

http://www.meteociel.fr/modeles/naefs_cartes.php?ech=192&code=1&mode=0&map=1&runpara=

http://www.meteociel.fr/modeles/ecmwf.php?ech=72&mode=1&map=1&type=1&archive=0

and the combined London ens temperature graph

 

http://www.weathercast.co.uk/services/ensemble-forecast.html

all indicating a rather cold north westerly pattern.

Of course these outputs only show general overall upper air forecasts.Surface synoptics will often vary day to day but they do give a good idea of what weather type we can expect in a given period and help to highlight any rouge operational charts,particularly useful beyond day 4/5 when we often see differences run to run between the models.

 

[phil nw.]

Just a heads up for the posters involved.We have moved some recent posts to the banter thread here

where they were more suited.

 

Edited February 28, 2016 by phil nw.

[Northern Sky]

Some really interesting posts regarding the anomaly charts. I know John H and Mushy have been banging on about them for some time and they really do seem to have been on the money this winter. It would be interesting to go back through the winter to times when the op runs have promised exciting winter charts only to let us down and review what the anomaly charts were saying at the time. Someone may remember but I can't. If, as I suspect, the anomaly charts weren't going for it then taking that into account may save some heartbreak next winter!

I for one am not getting excited about anything unless the anomaly charts support it from now on.

[SMU]

Whilst im pretty much resigned to no more snow here in our little part of the world - tonights UKMO is very good for areas a bit further North & infact the blocking element on that run is pretty good with a cut off high towards greenland at 144

[IDO]

6 minutes ago, Steve Murr said:

Whilst im pretty much resigned to no more snow here in our little part of the world - tonights UKMO is very good for areas a bit further North & infact the blocking element on that run is pretty good with a cut off high towards greenland at 144

I hope if we have learnt anything this winter, one thing that should be ingrained is how poor the UKMO T144 charts verify when there is an Atlantic ridge. It nearly always over blows heights in Greenland and not one has come to fruition. The most recent was about a week ago: T144 UKMO:  Actual: 

I am sure one will pop up eventually but I doubt it!

A rinse and repeat next week with not as cold uppers. Then GFS flattens the pattern out after the next Atlantic ridge topples after D8. As GFS is usually progressive re the Atlantic, maybe the topple will be slower than the GFS currently shows. 

As for snow, the fronts on Tuesday and late Thurs/early Friday look like rain, but the PM flow behind them should be wintry on northern hills, but hit and miss. Looks like after next week the MJO may weaken and we lose the better amplification for a while (w2 and w3 March?). So end of March to early April wait for a return for the NW flow and more cold rain for down south.