Model Output Discussion; into 2015

[nick sussex]

I think the lack of posts this morning speaks for itself!

 

A mobile picture overall with the PV in charge, the ECM develops some minor interest at day ten although given its recent performance at that range whether it survives until tonight is another matter.

 

In terms of the strat warming that's currently not sufficient to remove the limpet PV and now its all down to a possible second warming, I'd say at this point that needs to deliver to save January for those that want to see some more UK wide snow and cold.

 

Unless something unexpected happens in the meantime then the outputs might need a health advisory as they will be pretty grim viewing for a while yet.

 

Any major changes bar some miracle beforehand are unlikely till the second half of January so as much as I expect everyones patience has worn thin by now we're just going to have to hope that we do indeed see a change in a few weeks.

Edited December 30, 2014 by nick sussex

[bluearmy]

Yep, IDO, the gefs certainly catching onto events higher up.

I would caution against expecting definitive evolutions from the strat events until we see a correlation past day 7 with the ECM/gfs forecasts. They should be more in step than they are. If ecm is correct, then gfs is too strong with the Canadian vortex through week 2. The ECM ens say that gfs is right.

Edited December 30, 2014 by bluearmy

[johnholmes]

my view from the anomaly perspective with additional outputs based on NAO, AO and MJO

 

Tue 30dec

Ec-gfs

Both seem a bit more with trough feature than ridge south of it; both similar rest of chart, flow best described w’ly on both but maybe gfs touch further n of w?

With that shown on noaa 6-10 and 8-14 this pattern, strong w’ly over atlantic into uk and Europe seems fairly set for 2 weeks maybe bit more.

Mjo currently shows low amplitude phase 4, probably too low for any meaningful input but 4=not that different to what we have and the forecast shows it moving to 5 with some increase in amplitude; 5=v similar with even more –ve heights Norway-uk-atlantic into Greenland-ne Canada with +ve heights again Caribbean-azores –france/Iberia-europe

So again, the gfs mjo version shows nothing to suggest any major cold outbreak of any duration from any direction to me, of course others may dispute this, Finally both the ao and nao show not much sign of any major –ve departure,not that I use them much beyond 7 days anyway even for any confirmation signal. 

links

NOAA and ECMWF-GFS

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

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

and NAO, AO and MJO link

http://www.cpc.ncep.noaa.gov/index.php

 

It will not be popular but the Met O charts shown in the autumn for December to February look a lot closer to the mark than perhaps the ODI etc suggested. That said no serious amateur either really expected any deep cold until some time in January before it started to show. Currently the first half using my idea shows little to give deep longish lasting cold from any direction. But then as we all know the weather can and does make monkeys out of us all!

Edited December 30, 2014 by johnholmes

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY TUESDAY DECEMBER 30TH 2014.

NEXT UPDATE WEDNESDAY DECEMBER 31ST 08:00

THE CURRENT GENERAL SITUATION High pressure close to Southern England will decline SE over the coming day or so with a SW flow ahead of a series of fronts moving down from the NW over the period.

MODELS-2 WEEK HEADLINE Becoming unsettled and windy later this week and onward with rain or showers at times and snow on Northern hills. Some drier periods likely in the South.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Forecast shows the flow ridging North over the UK currently. It then flattens considerably while continuing to undulate slowly North then South around the vicinity of Southern England in the continuing programming of a Westerly flow across the UK.

GFS OPERATIONAL The GFS operational this morning shows High pressure collapsing SE into NW Europe over the next day or two with a freshening and less cold Westerly flow developing across the UK. A very mobile and zonal pattern is then shown through to the end of the run with strong West or SW winds across the UK with spells of wind and rain rushing East over all areas with somewhat colder and brighter more showery interludes in between with snowfall restricted to northernmost hills principally.

THE GFS PARALLEL RUN The Parallel run is very similar to the operational this morning in overall pattern with differences in specifics from day to day only in an otherwise flat pattern. There will be rain and showers at times in a strong Westerly flow but with High pressure flirting with the South at times it will be mild here for much of the time and rainfall will be less problematic. Some drier and colder incursions under ridges of High pressure may interrupt  the milder theme with some wintry showers over the hills of the North at times especially later.

THE GFS CONTROL The GFS control run also shows a strongly zonal pattern under Westerly winds developing for the North soon and to all areas soon after with strong winds and rain at times for all through the second half of the period in average temperatures or a little above at times apart from brief colder interludes at times in the North and some drier periods across the South as High pressure over France remains close by at times.

THE GEFS ENSEMBLES The GFS Ensembles show strong support for a Westerly flow to dominate the UK from later this week. With Low pressure biased to lie to the North and High near the Azores Westerly winds, strong at times will follow their normal characteristics of spells of wind and rain for all with slightly colder and more showery interludes in between, these most prolific across the North.

UKMO UKMO shows a mobile Westerly flow developing across the UK from today onwards. With Low pressure to the North and High to the South there will be fronts moving East in the flow bringing rain at times and short brighter, slightly colder conditions with showers perhaps wintry over the Northern hills.

THE FAX CHARTS The Fax Charts follow the raw data quite well today with a milder SW flow replacing the cold High across Southern Britain over the New Year. A cold front in the stronger SW flow will clear SE by the weekend with another broad warm sector approaching the UK from the SW later in the weekend following a brief chillier ridge on Saturday.

GEM GEM today shows a sutained milder period coming up across all areas as High pressure to the South and Low to the North maintains a Westerly feed of winds for all with rain at times especially over the North and West as the Low to the North feeds occasional troughs East across the UK with brief chillier periods in between.

NAVGEM NAVGEM also shows the well worn track between the models recently of replacing High pressure with a milder Westerly flow between High pressure to the South and Low to the North with rain at times with some brief drier and chillier days in between.

ECM ECM this morning shows the current High pressure moving away to the South with a freshening SW flow ahead of a cold front later in the week bringing some rain. This sets the trend this morning for the rest of the run with milder westerly winds for all and with High pressure to the South and Low to the North delivering fresh to strong Westerly winds and rain at times there will be some marked mild days at times in the South with just short-lived colder periods with showers, wintry at times on Northern hills in between.

ECM 10 DAY MEAN The ECM 10 Day Mean Chart shows Low pressure to the North and High to the South the most likely scenario at Day 10. This would indicate a strong Westerly flow with spells of rain mixed in with slightly colder and more showery conditions in between, this most likely over the North.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend this morning remains almost totally in favour of a broad Westerly flow across the UK with enough longevity to take us throughout the period this morning with next to no chance of any breakout of this pattern in the immediate future using the data available to me this morning.

MY THOUGHTS This morning's output offers total agreeance and cross model support for milder conditions to move across the UK over the next 48 hours and continue as the dominant factor for all areas throughout the next 10-14 days. With a flat Jet flow moving West to East across the Atlantic and the UK lying on the Southern flank of Low pressure well to the North of the UK and High pressure over the South. The resultant Westerly winds will often be fresh to strong and carry repeated troughs across the UK and carry broad mild sectors with them at times across the South too with temperatures above average in often damp, dull and windy conditions. Northern areas in particular could well see some colder polar maritime air at times as cold fronts pass over but these look fairly undramatic with any snowfall from the accompanying showers restricted to the higher hills even in the North before it all gets swept away by the next warm front sector. I can see no let up or clues from the charts to indicate anything other than this mild theme lasting at least until mid January at least and as I have been saying all season and continue to promote the Azores High is particulary strong and persistent this year and as it stretches into Southern Europe at times prevents all would be attacks from the North. So we have to rely on the science of Sudden Stratospheric Warming held within the temperatures of the atmosphere high above our heads which is scheduled to show a rise over the coming weeks across the Arctic which supposedly can propagate down to the troposphere and deliver a higher chance of cold to the UK some while afterwards. In the grand scheme of weather though even the experts at the Met Office admit there is still a lot of research and understanding needed to suggest that SSW will give rise to colder conditions per se with multiple complexities across the Northern hemisphere in general all having to come together at the same time to increase any chance of cold further. So while we don't see the results of this in the models we have to keep saying that it is going to stay mild for the foreseeable future with rain at times as the models remain resolute in showing nothing other than this.

[Frosty.]

Fax chart for friday shows progressively colder showery conditions spreading SE with the showers gradually turning wintry, especially in the north with snow on hills, by Saturday, after an overnight frost, a ridge of high pressure pushes in from the Atlantic but thereafter it turns unsettled, milder and windier.

[mountain shadow]

I think the lack of posts this morning speaks for itself!

Yes, finally the realisation that the picture is entirely mobile for the next couple of weeks whilst we wait and see whether the strat influences aid our shores in anyway.

Seems the ECM Strat forecasts are not as good this morning, so it may be the end of the month before we get any noticeable influence in line with the Met Office predictions.

Poor old OPI and SAI look like they need to worked on some more as clearly there are other factors over riding their theories, although things can still change quickly to save the day for them.

[mushymanrob]

I see nothing which suggests a mild outlook in the slightest, temperatures generally are either average or colder, this is pretty clear from the Ecm 12z ensemble mean, a strong and broadly westerly airflow veering from oceanic to polar Maritimes, indeed, the flow eventually looks like swinging more towards the north just beyond T+240.

 

but there has been a decided shift away from the time spent under pm air and an increase in the time spent under tm air over the last two days. it looks alot less 'early 1984' and much more average with parity between milder/colder spells between systems.

so no. its not a mild outlook, but its milder then it was two days ago.

[craigore]

I enjoy mods watching and have for many years especially of late , but never try and fall into the trap of  looking past day 7.. those experts among us that try to predict seasonal forecasts are flogging a dead horse as this is now the second winter on the trop that has been forecast to have a cold hearted winter (when predicted back at end of nov) 

I don't like to have my hopes dashed so therefore just look at what the mods are saying now, not nxt month...

Lets hope there will be something in store for February..

[Frosty.]

but there has been a decided shift away from the time spent under pm air and an increase in the time spent under tm air over the last two days. it looks alot less 'early 1984' and much more average with parity between milder/colder spells between systems.so no. its not a mild outlook, but its milder then it was two days ago.

Hi mushy, I agree, my post last night said cool to cold zonaity but I should have added some tropical maritime influence at times. Nice to see we are agreeing with each other a lot more these days :-)

Edited December 30, 2014 by Frosty.

[Snow and storms]

After visiting the strat forum for the first time and reading about the possible sudden strat warming forecasts in a few days caused by the wave activity, how is it this does not always result in cold weather for the uk? Surely the weather forecast will lag behind the strat forecasts and this is why we are seeing westerly flows in the charts.

Is it possible to have perfect strat forecast and still dodge a significant cold spell? (I think I know the answer to this question but I am not sure as to why) or is it likely either the strat forecast is incorrect or the chart forecasts have not caught up yet?

If anyone with far more knowledge than myself is able to explain why this is possible I would really appreciate it.

[alexisj9]

After visiting the strat forum for the first time and reading about the possible sudden strat warming forecasts in a few days caused by the wave activity, how is it this does not always result in cold weather for the uk? Surely the weather forecast will lag behind the strat forecasts and this is why we are seeing westerly flows in the charts.

Is it possible to have perfect strat forecast and still dodge a significant cold spell? (I think I know the answer to this question but I am not sure as to why) or is it likely either the strat forecast is incorrect or the chart forecasts have not caught up yet?

If anyone with far more knowledge than myself is able to explain why this is possible I would really appreciate it.

It really depends on where the blocking highs develop, if in the wrong place for cold for us we stay mild.

[fergieweather]

After visiting the strat forum for the first time and reading about the possible sudden strat warming forecasts in a few days caused by the wave activity, how is it this does not always result in cold weather for the uk? Surely the weather forecast will lag behind the strat forecasts and this is why we are seeing westerly flows in the charts.

Is it possible to have perfect strat forecast and still dodge a significant cold spell? (I think I know the answer to this question but I am not sure as to why) or is it likely either the strat forecast is incorrect or the chart forecasts have not caught up yet?

1. Depends on where any blocking establishes, & scope/longevity of this.

2. Typical lag time from SSW to surface response is circa 3 weeks

3. Confidence remains high in broadly W'ly regime for a good chunk of Jan

4. Tentative signals, currently low confidence, for increased blocking late Jan

5. Current lack of such (clear) signal in EC-EPS/EC Monthly unsurprising

6. Any emergence of unambiguous and impending pattern change via SSW will be clearly signposted in UKMO forecasts/communication, as was case in early 2013.

[winterof79]

I think the lack of posts this morning speaks for itself!

 

A mobile picture overall with the PV in charge, the ECM develops some minor interest at day ten although given its recent performance at that range whether it survives until tonight is another matter.

 

In terms of the strat warming that's currently not sufficient to remove the limpet PV and now its all down to a possible second warming, I'd say at this point that needs to deliver to save January for those that want to see some more UK wide snow and cold.

 

Unless something unexpected happens in the meantime then the outputs might need a health advisory as they will be pretty grim viewing for a while yet.

 

Any major changes bar some miracle beforehand are unlikely till the second half of January so as much as I expect everyones patience has worn thin by now we're just going to have to hope that we do indeed see a change in a few weeks.

Of course we must note that a swathe of the UK has had lying snow since Boxing Day,so lets not get too wound up in false expectation

http://s0.fast-sfc.com/map/img/uk.snow.last7days.cc23.jpg

[winterof79]

I enjoy mods watching and have for many years especially of late , but never try and fall into the trap of  looking past day 7.. those experts among us that try to predict seasonal forecasts are flogging a dead horse as this is now the second winter on the trop that has been forecast to have a cold hearted winter (when predicted back at end of nov) 

I don't like to have my hopes dashed so therefore just look at what the mods are saying now, not nxt month...

Lets hope there will be something in store for February..

Its December?? January is 4 weeks long and people forget that quite a few have had snow,which nobody saw coming through December.Chill people.

[Mr_Pessimistic]

1. Depends on where any blocking establishes, & scope/longevity of this.

2. Typical lag time from SSW to surface response is circa 3 weeks

3. Confidence remains high in broadly W'ly regime for a good chunk of Jan

4. Tentative signals, currently low confidence, for increased blocking late Jan

5. Current lack of such (clear) signal in EC-EPS/EC Monthly unsurprising

6. Any emergence of unambiguous and impending pattern change via SSW will be clearly signposted in UKMO forecasts/communication, as was case in early 2013.

. And if the strat warming does 'propagate' down to the trop, splitting the vortex into two pieces, I fully expect us to be stuck right in the middle of where the waa forms, giving us dry boring weather under high pressure. I will be surprised if the Greenland lobe backs west enough to put us on the cold side. All happening a month later then all the forecasts predicted, as it usually seems to..

[cornish snow]

I enjoy mods watching and have for many years especially of late , but never try and fall into the trap of  looking past day 7.. those experts among us that try to predict seasonal forecasts are flogging a dead horse as this is now the second winter on the trop that has been forecast to have a cold hearted winter (when predicted back at end of nov) 

I don't like to have my hopes dashed so therefore just look at what the mods are saying now, not nxt month...

Lets hope there will be something in store for February..

If you don't look more than 7 days away,how is it you can right off the whole of jan by saying you hope something is in store for feb?

7days from now is Jan 6th!

 

Having said that,i take your point. Presonally,i don't look much more than 5 days ahead.

[legritter]

I enjoy mods watching and have for many years especially of late , but never try and fall into the trap of  looking past day 7.. those experts among us that try to predict seasonal forecasts are flogging a dead horse as this is now the second winter on the trop that has been forecast to have a cold hearted winter (when predicted back at end of nov) 

I don't like to have my hopes dashed so therefore just look at what the mods are saying now, not nxt month...

Lets hope there will be something in store for February..

There could very well be something more wintry in store for the second half of January .met office hinting on long range forecast ,of course this is data charts we do not see .that hint is based on current data ,but to be honest in my opinion if over the horizon there is a northern block possibly modeled i,m sure we would see it sooner .so we just have to hope that soon we will see atlantic lows being modelled further south and heights in the arctic more noticeable  as the days go on .ok todays charts look typical winter fayre but past 10 days even 8 days we  could be looking at a new chapter .it realy is patience but we still have plenty of winter left .so from todays charts nothing of note regards real cold and snow but a fair chance that the atlantic could get very active past next say wednesdsay 7th january and if but not a big if, lows take a more southerly course we could be in for some fun here on the best forum ,would not have thought 10 days ago that my local lanes would have ice by the bucket load and pond frozen over and my carrots frozen solid in the ground ,Meteorology full of surprises ,catch up with you all on tonights charts ,   :drinks:I was quoting met office 30 day forecast with hints of colder drier settled weather ,but read into it at your peril but they do have some good software and have  come up trumps in the near past .2013 as an example ,cheers 

Edited December 30, 2014 by legritter

[johnholmes]

In very simplistic terms, much as I suggested new folk try last evening.

 

The next week or so for my area from the 06Z run, they look a touch higher than the 12z yesterday showed?

 

2-4,3,9,5,4-5,6-7,5-6,4-5; even so with the average for my area of around 7C much of the time it is predicted to be at or below that value.

Certainly nothing as cold as the last 4 or 5 days with 4.4, 3.3, 3.4 and 4.9 up to yesterday.

[Jason M]

If asked to create the most hideous winter chart I could imagine, I might simply copy and paste this chart :-)

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=240&mode=0&runpara=1

That is so bad that it's actually pretty funny :-)

I suppose the best thing about this is that it simply doesn't get worse than that one, so quite literally the only way is up!

[IDO]

Of course we must note that a swathe of the UK has had lying snow since Boxing Day,so lets not get too wound up in false expectation

http://s0.fast-sfc.com/map/img/uk.snow.last7days.cc23.jpg

 

GFS 06z remains zonal from Jan 1st through to mid-Jan, ending: 

 

GFS P @D10: 

 

The GFS op may be too bias Atlantic wise as the GFS P may be too slow, so somewhere in between, but zonal looks on the cards with the South possible getting longer drier interludes. The GFS P offers the alternative (N/S split) where we get the Atlantic run over the Azores, and the consequence maybe:

 

Unlikely as the P does over do heights but very mild!

 

GEM Mean D10 and D16:

 

 

[karyo]

If asked to create the most hideous winter chart I could imagine, I might simply copy and paste this chart :-)

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=240&mode=0&runpara=1

That is so bad that it's actually pretty funny :-)

I suppose the best thing about this is that it simply doesn't get worse than that one, so quite literally the only way is up!

We have to see the funny side especially when we consider how promising the signals for this winter were a couple of months ago.

 

Frustrating to see the stratospheric forecast at 30hpa level. Warming gets going over north Atlantic edging towards the southern tip of Greenland and then it just recedes and the polar vortex re-organises after a brief stretch.

Edited December 30, 2014 by karyo

[DIS1970]

Just been having a look through the archives on Wetterzentrale and in the winter of 1990/91 it took more of less the whole of January to change the pattern from zonal conditions to the bitter cold & snow we had in early February, so anything is possible yet.
 

[Long haul to mild]

If asked to create the most hideous winter chart I could imagine, I might simply copy and paste this chart :-)

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=240&mode=0&runpara=1

That is so bad that it's actually pretty funny :-)

I suppose the best thing about this is that it simply doesn't get worse than that one, so quite literally the only way is up!

I clicked on that link determined to find something to cling to, some redeeming feature. "It can't be that bad" I thought. But you're right, it's a disgusting chart if you are looking for cold.

I still think later in Jan may bring something far better though, we just have to ride out this boring Atlantic period in the meantime.....

[Long haul to mild]

We have to see the funny side especially when we consider how promising the signals for this winter were a couple of months ago.

 

Frustrating to see the stratospheric forecast at 30hpa level. Warming gets going over north Atlantic edging towards the southern tip of Greenland and then it just recedes and the polar vortex re-organises after a brief stretch.

On the positive side though, strat forecasts change each day too and I would still say that the trend is in the right direction. Whether or not we benefit from any warming is another matter though of course!

[karyo]

On the positive side though, strat forecasts change each day too and I would still say that the trend is in the right direction. Whether or not we benefit from any warming is another matter though of course!

Yes, there's been numerous warmings on the Asian side which have not benefited us as they tended to push the polar vortex towards our side. That's where the frustration is that the forecasted Atlantic warming has a much better chance to lead to favourable blocking for us but I can't help but feel that it needs more strength. If only it could upgrade in future runs.

Edited December 30, 2014 by karyo