Model output discussions pm 31/12/15

[Mucka]

7 minutes ago, nick sussex said:

Of course the ensembles can be helpful when they're not plucking a solution that looks totally against the background signals and theres a decent clustering around an outcome but still they're prone to some wild swings. Personally I'd shred all GFS operational runs past T240hrs and use them as cat litter! With 4 runs a day it gets lauded sometimes for picking up on the right solution when in fact all its done is throw 4 different solutions out and the odds eventually favour that it will be right eventually!

Anyway this counts now as two GFS moans from me so I'd better move on!lol

 

Totally agree with Op past 240, thought you were referring to all output.

The height rises signaled within ensembles (maybe just a few at first then half a dozen etc so strengthening signal) to our E were against all background signals at the time though and so were other signals for mid lat blocking. I just take a mental note of each chart and synoptic as I run through and if something different pops up and gets repeated by another ensemble or two I watch for it again in the next set and so on. I may comment after 2 or 3 runs suggest something - depending on how brave I feel.

 

The best part is that if it all goes Tits up I just blame that useless GFS!

Edited January 1, 2016 by Mucka

[Midlands Ice Age]

8 minutes ago, blizzard81 said:

That sounds like very poor wording from Louise. 

Nope ...

She was definite about it, but I wonder if she was using yesterday's charts?

She even produced a chart to show the way the jet stream was expected to split at the end of the week, with most energy going south!!

Edited January 1, 2016 by Midlands Ice Age

[Spah1]

5 hours ago, Ali1977 said:

 

12 minutes ago, Midlands Ice Age said:

Hi guys,

Just been watching Louise Lear on News 24  for the week ahead forecast.

Very interesting   -  She is now going for strengthening heights over Scandy and the north Atlantic - by the end of the week(!), with low pressure systems gradually filling and moving south from Southern England.

The mention was of snow showers over Scotland by the end of the week and much colder air from Scandy.. 

Now where has that come from.?

Presumably one of the models seen and used  internally has flipped this evening.

Where is Steve M? He hasn't been seen today so could he have been somewhere in the Met Office?

Tonights runs may become more interesting, but I will leave them for the night shift as I need to catch up some sleep from last night!

Is this the Steve Murr switch?

 

She's describing exactly what the models are showing over the next 5-7 days. 

[Eskimo]

15 minutes ago, Midlands Ice Age said:

Hi guys,

Just been watching Louise Lear on News 24  for the week ahead forecast.

Very interesting   -  She is now going for strengthening heights over Scandy and the north Atlantic - by the end of the week(!), with low pressure systems gradually filling and moving south from Southern England.

 

That's exactly what the models are showing, but it gets replaced very quickly to a more Atlantic dominated theme. Nothing new unfortunately. 

[booferking]

4 minutes ago, Midlands Ice Age said:

Nope ...

She was definite about it, but I wonder if she was using yesterday's charts?

What she is saying is what the charts are showing lows filling sink slowly south, cold air just in Scotland with a chance of snow if she done her forecast any further it would then say Atlantic taking over at the end.

Edited January 1, 2016 by booferking

[Carlrg]

Just watched the live weather on News 24, definitely mentioned cooler and drier conditions coming in from the East. 

[blizzard81]

3 minutes ago, Midlands Ice Age said:

Nope ...

She was definite about it, but I wonder if she was using yesterday's charts?

She even produced a chart to show the way the jet stream was expected to split at the end of the week, with most energy going south!!

You could indeed be right about using old data. I have found that happens quite a lot with the meto. Hoped they had sorted that problem out by now though.

[cornish snow]

2 minutes ago, Carlrg said:

Just watched the live weather on News 24, definitely mentioned cooler and drier conditions coming in from the East. 

No mention just on BBC 1 just rain,rain,rain. Brief respite on tuesday,more rain on wednesday.

[nick sussex]

Relatively speaking it will feel much colder. However I can't see some model flip in terms of an easterly, the Atlantic low approaching at T120hrs might give some snow more especially for the ne UK. Its conceivable that the cold could hang on a bit longer in the far north.

I think we're going to have to look to see whether we can get a displaced Azores high with troughing to the east/ne which would at least have some background MJO support.

[swilliam]

30 minutes ago, nick sussex said:

Of course the ensembles can be helpful when they're not plucking a solution that looks totally against the background signals and theres a decent clustering around an outcome but still they're prone to some wild swings. Personally I'd shred all GFS operational runs past T240hrs and use them as cat litter! With 4 runs a day it gets lauded sometimes for picking up on the right solution when in fact all its done is throw 4 different solutions out and the odds eventually favour that it will be right eventually!

Anyway this counts now as two GFS moans from me so I'd better move on!lol

I agree with Mucka on this one. I do not really pay much attention to the Op (count it as one of the ensembles). But looking at the 10-15 day ensembles it is often apparent that there are some tendencies appearing. I am not a fan of the mean at this range as this just normally shows the climatological average - i.e zonal westerlies. However when it shows something different to this then it is useful. In fact this is the case just now  - below is the mean at +384 showing a pronounced ridge in the vicinity of the BI. What this means to me is that there is likelihood of significant height rises in our area at this range. Now as this an average the exact position is completely undefined. Looking through the members there are UK highs, Scandi ridges and height rises to the NW. There are are of course zonal options also toning down this signal. The most common options over the last few runs (of those showing height rises)  are the UK high and the Scandi ridges rather than the Greenland high though. But any of these are possible. The main point is if these options were not being shown then we would know that nothing is likely in the next 15 days . So this is the main point in my view. If no meridional solutions are being shown then more zonal is highly likely. If we have some more blocked options then this is much more possible and we can start looking how this may develop and where it may or may not set up.

 

 

It seems to me if we do not use these then all we have is the Meto 30 dayer and some info from IF about the other models (Glosea EC32 etc). So I more I am more than happy to look at these as it is the best we have (not the OP in isolation though - comments on this are pointless).

[Mucka]

 

Perhaps a few colder options on this evenings set. around mid month. Nothing significant though.

Edited January 2, 2016 by Mucka

[Daniel*]

Those heights over Scandinavia is there a minutest chance, the models may be removing heights too easily from this region? The timeframe is within 24 hours so a Christmas miracle and a half if there was a drastic change. 1044mb block should be quite sturdy - what's causing it to set sail rather quickly to the NE? 

Edited January 2, 2016 by Daniel*
Spelling!

[Mucka]

I would say GFS hasn't got a Scooby Doo after 96h at the moment given the changes run to run.

It develops and does something different with the Atlantic trough every run which can make quite big changes to the weather on the ground we experience, especially rainfall totals, wind strength and snow chances. All the GFS is saying is unsettled which we already know.

This time it develops the trough and anchors it in the Atlantic for a few days before finally pushing it East of the UK some 5 days later. That would be utter tedium and just bring wind and rain with no risk of snow to any low lying areas of England. It couldn't produce a worse 10 days of weather from these starting conditions for coldies and anyone sick of wind and rain if it tried. It needs a good kicking frankly  (FI may be another matter though)

UKMO has been more consistent and it has the trough organised and just to the NW of Ireland

It is annoying the public just get thrown scraps of what they pay for by way of model output, pretty much just the bare bones. 

I would take a guess high ground would see snow along with some lower levels further North from that but I stand to be corrected on that.

Edit

And here is GFS FI, Atlantic ridge meets Arctic high?

We have chased our phantom Easterly, now anyone up for chasing a Northerly?

Edited January 2, 2016 by Mucka

[knocker]

The more or less stationary area of low pressure over and adjacent to the UK hangs around until the middle of next week before the mobile regime get's into gear once again with depressions winging along on the jet. The Thursday one takes the expected turn NE but even then could bring some very strong winds, possible 80kt gusts, to the NW of Scotland. The next arrives the beginning of next week slap bang over the UK but this is academic at the moment as this will obviously be revised in the next few days. Towards the end of the run signs that the HP to the SW becoming more influential. I only mention this because it's a theme that has cropped a few times recently so worth keeping an eye on as it would bring a welcome relief from the Atlantic battering.

Charts weatherbell and http://www.tropicaltidbits.com/

Edited January 2, 2016 by knocker

[Vorticity0123]

As Knocker mentions above, we are bound to see a rather unsettled spell of weather the coming days. Looking at the ensemble forecasts, there seems to be an elevated chance on storms hitting southern parts of the UK and the Benelux starting from Thursday.

ECMWF ensemble wind gusts forecast [m/s] for De Bilt (NL) as of 12Z 01-01.

A number of members (including the operational) are hinting on wind gusts above 40 miles per hour in De BIlt, roughly in the center of the Netherlands. Note that the green lines all have relatively low resolution, so the true wind gusts in these ensemble members could be even higher. There remains a lot of spread, but a storm is very likely to occur between Thursday and Friday.

 

ECMWF ensemble wind direction forecast [m/s] for De Bilt (NL) as of 12Z 01-01.

Finally, also the southwesterlies are set to return, and with great consistency at the long term given the narrow bandwith in the ensembles. Mild seems to be the main theme, though not as mild as the record-shattering December has been.

Source:

http://www.weerplaza.nl/15daagseverwachting/?type=eps_pluim

[knocker]

Not surprisingly the ecm treats the low next week differently to the GFS. It has some very complex phasing of low pressures in the Atlantic which by 0600z Thursday has resolved into the main area of LP 500m west of the Hebrides 936mb with a shortwave developing SW of Ireland. By 12z this is a depression 962mb over Scotland with much rain and some significant and snowfalls on the high ground. The winds would be less of a problem with this scenario.

[KTtom]

Its also worth noting that the overall pattern of transfering the deep low (vortex) initially over and then to the east of the UK is shown by both ECM and GFS, although painfully slow, with better heights over Greenland following on it does look like there is a real possibility of a decent northerly brewing for mid month..

 

Edited January 2, 2016 by KTtom

[tinybill]

8 hours ago, Mucka said:

 

Totally agree with Op past 240, thought you were referring to all output.

The height rises signaled within ensembles (maybe just a few at first then half a dozen etc so strengthening signal) to our E were against all background signals at the time though and so were other signals for mid lat blocking. I just take a mental note of each chart and synoptic as I run through and if something different pops up and gets repeated by another ensemble or two I watch for it again in the next set and so on. I may comment after 2 or 3 runs suggest something - depending on how brave I feel.

 

The best part is that if it all goes Tits up I just blame that useless GFS!

the gfs is hinting of a possible change about jan  i2  -14  for a couple of days  i cant seen any longer term

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=222&mode=2

 

[Frosty.]

The models are showing an angry atlantic next week with plenty more wind and rain on the way along with milder conditions and I suspect more flooding for the same areas previously affected...

[karlos1983]

Yup, looking at the main 3 this morning, if I was looking for a trend it certainly seems to me that we could be eyeing up a northerly around mid month. UKMO obviously doesn't go out far enough but you can see how it could get to a northerly Fromm its 144. 

UKMO

 

[IDO]

The UK Atlantic quadrant is resolved in terms of long wave pattern for about 10 days, with from around D4 a piece of vortex slowly moving through to the North of our region. This has been rocks solid for over two days and am not expecting any changes. Not going to guess at this range how the upper air profile or the mesoscale detail to these shortwaves carried through by that vortex. Taking into account just the 0z and 12z runs, as my faith in the other GFS runs is low, then snow for the south has always been unlikely (5-10% at best):

GEFS    mean at D16:  Clusters: 

Very little sign of cold and if you ignore the OP run after D10, and you have to as it is a text book outlier (at the moment), then the guide from the mean is Greenland/NE Canada again becoming home for a core vortex chunk, with the UK the target for the Atlantic train, with a N/S split as to the worse of the rainfall. The signs from 24 hours ago of an Atlantic Ridge being a strong cluster have in the last two runs trended away from such a setup, as the above clusters show (at D15). Early days to make any sweeping statements on that development.

With the Atlantic wave as currently seen now confidently set to roll east/SE and the mean surface high to hang around Siberia/Russia that is no longer likely a driver for the UK after D5. The wave from the Pacific forcing is a ridge in the East Pacific and once that EPO block detaches from the ridge, where those residue heights/block meander to is what is causing the upstream uncertainty. I would normally expect them to migrate to aid the Russian block, but as you would expect at this range, the GEFS are very wishy washy about how this will play out:

  D10 variety ECM and GEM: 

ECM splits the wedge early sending it back into the Conus ( around D7 for a couple of runs now) with the rest sent to pump up the Siberian/Russian HP.^^^So expect lots of variability after D10 as to the NH profile re this wedge of heights. 

The MJO from most models are coming through with a quick run through phases 7 and 8 over the next ten days, the GFS which has been playing catch up is slower to push through. As you can see from the 2 week verification GFS is struggling with the current MJO signal:

GFS verification:    The ECM mean as a guide: 

It looks like a case of waiting for the models to settle down with respect to after the D10 period, and to see how the big picture unfolds as to the lag up to the strat, and hopefully the strat PV gets a well placed attack timed as its strength wains?

 

[carinthian]

Good Morning, maybe this chart from ECM will lead to a snowy situation. A real good mix of Ac airmass out from Scandinavia and N Atlantic Pm with well below uppers  would produce the goods up North, but its always in the outer reaches of the model perimeter. Still we wait here in the Alps !

C

[Summer Sun]

Eastern parts of Scotland look the most at risk of flooding in the short term some rain for the flood hit areas but not as bad as of late

Running on another few days and the totals rise quite so further flooding would be inevitable unfortunately

Scotland looks best placed to see any snow in the next 10 days maybe a dusting for the pennines at times but nothing of significance

[Liam J]

The chart KTtom posted above for the 14th looks very similar to how the ECM monthly control evolved but a few days later, so maybe the outer reaches of the GFS are also picking up on this potential northerly mid month... All very much in FI so lets hope it's a trend that sticks and not another false dawn! Looking at the GEFS they look a tad underwhelming and some signs longer term for height rises to the south once again, but all in FI and it really looks quite a mess.

Shorter term looking unsettled with wet & windy weather but cooler than of late with a risk of snow especially in the north and over higher ground.  

 

 

Edited January 2, 2016 by *Sub*Zero*

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON SATURDAY JAN 2ND 2016

THE CURRENT GENERAL SITUATION   A filling depression will move slowly NE across the UK today followed by an active trough associated with a deep Atlantic depression following NE across the UK tomorrow followed by a vigorous and showery SW flow across the SW.

http://www.wetterzentrale.de/pics/Rtavn001.gif

CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the British Isles ranges from 4000ft asl to 6000ftasl North to South across the UK today with snowfall restricted to higher summits of Scotland today.

http://www.snow-forecast.com/maps/dynamic/uk

http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif

MODELS-2 WEEK HEADLINE  Continuing unsettled and very windy at times with further heavy rain or showers at times with snow possible on Northern hills for a time next week at least.

THE GFS JET STREAM FORECAST  The main theme of the Jet Stream shows the flow remaining strong across the Atlantic for most of the next few weeks. For most of the time it runs East just to the South of the UK, strongly at times before a slow drift back North through Week 2 culminating in a change to a more undulating flow over and around the UK towards the end of the period in a somewhat lighter form than currently.

http://www.netweather.tv/index.cgi?action=jetstream

GFS OPERATIONAL The theme of the GFS operational run today shows the next week to 10 days as being wet and very windy at times across the UK in variable and cyclonic winds as Low pressure continues to move across the UK from the West. They then move somewhat more to the North by a weeks time with SW gales or severe gales delivering spells of heavy rain mixed with showery periods and at any time there looks the risk of some snow over Northern hills at times. Then in the second week winds switch more to the North or NW with colder weatehr for all with wintry showers and frost at night with pressure rising to the SW leaving the UK in a breezy and somewhat chilly NW flow to end the period with further showers in the North and East.

GFS CONTROL RUN The theme of the Control Run is very similar to the Operational run this morning with the wet and very windy spell continuing over the next 10 days or so with the same build of pressure to the South late in the period bringing drier weather to all, still with some rain and strong Westerly breezes in the North and West with some rain at times.

http://www.wetterzentrale.de/pics/Rtavn1441.gif

http://www.wetterzentrale.de/pics/Rtavn3841.gif

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=144&mode=0&carte=0

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=384&mode=0&carte=0

UKMO The UKMO today continues to look very unsettled across the UK next week as Low pressure close to Southern England early in the week only slowly fills and ebbs away East to be absorbed by a new powerful Atlantic Low pressure South of Iceland towards the end of next week sweeping more heavy rain and strong winds NE across the UK late in the period. Some snowfall is likely across the higher ground of the North and East through the early stages of next week with adrier interlude for many before the main depressions spins gales and rain NE followed by squally showers to all areas by next weekend with wintry showers possible over the hills of the North.

http://www.wetterzentrale.de/pics/Rukm1441.gif

THE FAX CHARTS The Fax Charts main theme today continues to show Low pressure across or near the UK over the next 5 days with rain and showers and some snow on Northern hills on the Northern side of troughs slow moving over the far North.

http://www.weathercharts.org/ukmomslp.htm#t120

GEM GEM this morning maintains very wet and volatile conditions across the UK throughout it's 10 day span with plenty more deep Low pressure running into the UK from off the Atlantic with rain and showers aplenty and rather colder conditions than of late delivering some snow at times to the hills of the North and NE. Then late in the run Low pressure centred more to the NW brings SW gales for many with heavy rain at times for all, becoming heaviest again towards the West and NW by the end of the period with milder conditions re-emerging across the South.

http://www.wetterzentrale.de/pics/Rgem2401.gif

NAVGEM NAVGEM too offers the same ingredients as the rest of the output for the next 7 days with rai at times and rather chillier conditions than of late with some snow on the hills of the North and NE and gales at times in the South. Then later next week deep Low pressure to the North and NW return SW or West gales to all with rain or showers at times in bear average temperatures.

http://www.wetterzentrale.de/pics/Rnvg1681.gif

ECM ECM today shows very low pressure across the UK over the next 10 days or so. Low pressure will lie over the UK in the coming 4-5 days before becoming more to the NW and North later in the period. This will result in chillier conditions early in the period as winds are cyclonic and variable though still strong in places and in the chillier air some snow may fall on higher ground of the North and East. Then later in the run as the Low centre's lie further to the NW SW gales and heavy rain will sweep East across all areas followed by spells of sunshine and showers heavy at times with near average temperatures restricting any snowfall to the hills of the North.

http://www.wetterzentrale.de/pics/Recm2401.gif

ECM 10 DAY MEAN The 10 day mean chart remains poor with unsettled conditions across the UK maintained in a largely Westerly flow. The Jet Stream remains likely to be positioned a long way South so conditions are unlikely to be particularly mild but equally not that cold either with the main message being further wind and rain across the UK especially to the West and NW and any snowfall rstricted to the high ground of the North only.

http://www.wetterzentrale.de/pics/Reem2401.gif

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The theme of the output longer term today shows no significant let up in the basically wet and windy conditions though a growing trend for High pressure to build to the South of the UK again is hinted at as we approach mid January.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ahead at 99.6 pts with UKMO  at 96.5 pts and GFS at 99.4 pts.  At 3 days ECM is leading with 97.5 pts to UKMO's 96.7 pts while GFS lags behind at 96.1 pts. At 5 days ECM leads with 89.4 pts to UKMO at 87.3 pts then GFS at 85.9 pts. Then at 8 Days ECM still leads at 62.8 pts over GFS's 59.4 pts. Finally at Day 10 ECM leads GFS at 46.6 pts to 44.3 pts. 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day1_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.png

MY THOUGHTS   There remains little cheer from the models this morning as the Atlantic remains in total control of the weather over the UK through the next two weeks. There are of course day to day differences through the period and the main differences lie with the angle of attack that Low pressure takes at the UK through the period and the consequences thereof. For the next four or five days Low pressure areas take a course further South than of late with Southern England home to Low pressure at this time. This brings spells of rain or showers to all areas but in the North and NE some colder continental air could allow some wintry precipitation at times as it feeds West on the Northern flank of Low pressure from Northern Europe. On this morning's output this looks unlikely to be a major feature though with rainfall amounts remaining a major local problem with flooding in the NE and SW. Then a change of orientation of attack of Low pressure to a more NW'ly location drives renewed gales and heavy rain NE across all areas pushing away any colder air still in the NE and leading all areas into Westerly winds and heavy rain and showers at times in average temperatures. This theme then looks like continuing on for some time with a hint this morning that High pressure could begin to play a role in our weather towards two weeks from now. However, on this morning's output it's positioning looks unlikely to be favourable to support cold conditions for long if at all as it looks like that if it does develop it will lie to the SW or South with the South becoming dry and bright while the North continues to see some influence of Westerly winds and rain or showers. All this is a long way off though and caution of this evolution is of course the buzz word here. However, whatever does transpire it continues to look unlikely that any significant wintry weather away from Northern hills and mountains looks likely over the next few weeks at least given the theme and cross model evidence of this morning's output. 

Next Update on Sunday January 3rd 2016 at 09:00 approx