Model output discussion - 21st Jan Onwards

[Nick F]

Yes, some interesting developments on the 00z runs, apart from GFS! ECM and GEM both bring a northerly next Weds/Thurs, UKMO looks like it could load up a northerly at t+144. GFS has too much upper flow energy across the Atlantic and a northerly could quite easily be scuppered on the other models too if secondary lows are picked up blocking a northerly flow getting south across the UK.

Always difficult to get hopes up on a northerly at that range given the upper profile to the north and west of the UK unless more amplification works into the Atlantic sector. 

Edited January 27, 2016 by Nick F

[Ali1977]

The midlands and southern England away from the coast would be getting a dump of snow if this were to verify.

[Nick F]

21 minutes ago, Ali1977 said:

Nice ECM at 192/216 with -8 uppers over the UK, can we get that Atlantic low to slide underneath now I wonder 

That low on the EC at t+192/216 crossing the North Sea has got storm surge written all over it.

Day 10 EC high res ties in with what the extended EPS mean has been indicating over recent runs to dig troughing  / upper vortex deeper into Western Europe, so bye bye Euro High ...

[terrier]

So the ecm and gem want to bring a short lived northerly next wed Thursday but caution required as the gfs wants none of it as such. And as we saw a few weeks ago the gfs was showing the correct outcome when some of the other models were churning out eye candy runs. Don't get me wrong the ecm and gem could be right but I'm wary after last time.

[chris55]

Hmmmmmm....

Best run re cold from ECM for a while. From 144 the -4 isotherm is draped over pretty much the entire country!

northerly flow followed by that "unassuming" wedge of high pressure to the north west, it doesn't look much but sometimes you don't need those classic massive high pressures to deliver the goods.

240 slider looks very interesting!

 

[IDO]

No change from the GFS this morning with the overall zonal pattern out till D16. Overall mild for the rest of Jan but Feb starts closer to the seasonal average:

  CFS w1 and w2: 

The forecast period of colder uppers in around a week's time has, as I was expecting been warmed out with shortwave activity. So for the south rain and wind the main theme for the foreseeable, though N England and Scottish high grounds, as you would expect, likely to be more wintry. 

ECM and GEM between D7 and D8 make more of the transient Atlantic Ridge and manage to get a brief northerly:

  GEFS mean: 

At that range lots of modifications expected so low confidence at this time. The GEFS mean^^^ not too promising re that development and it is very borderline on the other models. The differences occur with respect to the Arctic High, both GFS and ECM have it at D7-9 in the same area but ECM tentatively links it with the Atlantic ridge and that acts as a block to the PV lobe towards Scandi to prevent that reconnecting with the residue low heights to the NW. The GFS does not have this Artic-Greenland connect so the energy slides back west:

GFS @ D10:  ECM 

And of course both GEM and ECM rely on that synoptic to allow some of the Atlantic to undercut the Greenland area D9-10.

No idea which way this will go though the ECM and GEM are obviously better for the longer term as they will take us away from the current pattern.

[Frosty.]

The Ecm 00z brings a welcome taste of winter next week to much of the UK with snow, ice and increasingly sharp frosts. It's always nice to see -10 T850's into the UK!

[karlos1983]

Well certainly the best morning of model output for some time. Very happy with the trend, banishing that euro slug which opens up the possibility of something more sustained in way of cold. Definitely looking like an interesting February coming up. ECM and UKMO are my favourite output of the morning. 

 

Edited January 27, 2016 by karlos1983

[mb018538]

John Hammond on the BBC extended outlook last night also suggested there are hints of a colder change around mid month. Maybe we're seeing the first few building blocks being cemented down this morning. ECM especially looks a peach! SSW could also help to slow the Atlantic train down.

[Banbury]

22 minutes ago, karlos1983 said:

Well certainly the best morning of model output for some time. Very happy with the trend, banishing that euro slug which opens up the possibility of something more sustained in way of cold. Definitely looking like an interesting February coming up. ECM and UKMO are my favourite output of the morning. 

 

I wouldn't disagree with that , the odd poster on TWO think the 0z runs are poor.......not sure who that can be the conclusion. As you say trends, and it does seem we are very slowly edging towards a different pattern

[mountain shadow]

Best morning output for a while.

Both ECM and UKM split the PV allowing a small rise in pressure near Iceland which slows down the Atlantic train and offers the chance of some interesting wintery synoptics. 

The GFS as ever powers the jet up and has the PV as one solid mass to the North with no split.

 

[Summer Sun]

So next week ECM has a northerly GFS doesn't

[The Beast From The East]

1 hour ago, Ali1977 said:

Nice ECM at 192/216 with -8 uppers over the UK, can we get that Atlantic low to slide underneath now I wonder 

Lets hope so but we've been here so many times where it looks like the low will slide under but it never happens for us sadly.  Yet in the past back in the 80s I can remember  lows sliding under one after the other  and snow galore .

[Day 10]

A bit more positivity around this morning for coldies and understandably so.

GFS and ECM similar at 144 and gfs out on it's own as per usual! So at least we aren't talking 240hrs anymore. Slowly but surely the models have been improving our chances of seeing colder weather return, then hopefully the snow will follow.

Better:

GFS getting his coat:

[karlos1983]

39 minutes ago, Banbury said:

I wouldn't disagree with that , the odd poster on TWO think the 0z runs are poor.......not sure who that can be the conclusion. As you say trends, and it does seem we are very slowly edging towards a different pattern

I don't know of this TWO people speak of. But it's been painful the past few days, and it was always going to be a case of just accepting a good 10 days of "meh" weather/model output. For me, I couldn't even get interested until the Euro heights are shown the door. I'm not sure what the TWO folk require to be happy though to be honest, because this mornings output is a massive move in the right direction? Perhaps they prefer south westerlies or are expecting 2 foot of snow? 

 

[coldcomfort]

Definitely a more 'encouraging' ECM this morning regarding the potential for a colder pattern, but given it won't be the first time it's flagged something like this post T+144hrs this winter, I think caution very much remains the watch word - especially in view of the fact GFS once again doesn't want a bit of it. UKMO also looks pretty decent at 144hrs, but again it has done so several times this winter, so I'd personally like to see something similar at T+96hrs from them before getting the warm coat back out.

 

 

Edited January 27, 2016 by coldcomfort

[terrier]

So gfs not showing a northerly next week. I'm wary of the ecm and gem this morning. Because I seem to remember the last cold blast the gfs been out on its own but in the end proved closer to the mark. More runs needed once again I think seems to be a theme this winter. 

[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 WEDNESDAY JAN 27TH 2016

THE CURRENT GENERAL SITUATION   A series of fronts will move slowly SE across the South and East of the UK today with a strong and mild SW flow ahead of them. Once passed a colder and slacker flow arrives under a ridge of High pressure before a strong WSW flow returns to the North and West later tomorrow.

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

 CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the British Isles ranges between 8000ft over the SE of England to just 1500ft across Scotland where snowfall has occurred and will continue in showery form today. In the South the freezing level will fall to around 4000ft for a time tomorrow.

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

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

MODELS-2 WEEK HEADLINE  Mostly unsettled and windy with rain or showers. Fluctuating temperatures with some snow at times over higher ground especially in the North.

THE GFS JET STREAM FORECAST  The Jet Stream forecast today shows the flow continuing to dominate the weather across the UK over the next few weeks as it remains strong throughout and blowing West to East across the UK for much of the time with small undulations both North and South while remaining between the confines of 50-55 deg North if the Equator.  

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

GFS OPERATIONAL The GFS Operational Run today shows a continuing period of very volatile weather across the UK alternating between wet and very windy conditions mixed with colder brighter weather with showers, wintry at times. Low pressure will be maintained to the North and High to the South through the first week. Temperatures will range between somewhat mild and rather cold as more showery air crosses over at times with the theme of particularly stormy weather shown at times in the second week for all as the axis of Low pressure moves further South than in the first week.

GFS CONTROL RUN The theme of the Control Run today shows unsettled and very windy weather too with rain at times under the same synoptic pattern as the Operational Run although for a time in the second week High pressure closer to the South offers another spell of very mild if windy SW winds with rain slow moving across the Northwest before swinging SE again into a more mobile pattern later on. 

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

GFS ENSEMBLE DAY 14 DATA  The GFS Clusters show a unanimous theme of winds from a West or NW source in two weeks time, still strong and with enough influence from Low pressure to the North and NW to ensure further rain and showers at times for all areas in fluctuating temperatures but never desperately cold.

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

UKMO The UKMO model this morning shows continuing Westerly winds and spells of rain alternating with colder and more showery interludes with some snow in the North especially later as the Low complex drifts towards Scandinavia in winds which swing more towards the NW ahead of a ridge of High pressure moving in from the West on Day 6.

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

THE FAX CHARTS The Fax Charts today show plenty of troughs crossing the UK in an often strong and blustery wind from the West. Temperatures will range between more often mild in the South and rather colder in the North with all areas seeing rain at times as both warm and cold fronts continue to affect all parts of the UK at times.

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

GEM GEM this morning also maintains Atlantic domination in the weather over the UK through the next 10 days with further spells of rain at times in strong Westerly winds. On this run there is a more definitive period of quieter and colder weather towards the middle of next week as a strong ridge crosses East before wet and windy weather returns from the West by the end of the 10 day period.

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

NAVGEM NAVGEM today also shows a volatile and windy spell of weather with spells of rain and strong winds with colder more showery conditions moving down from the NW by the middle of next week as a weak ridge pushes North into the Atlantic.

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

ECM ECM today will raise a few eyebrows within the cold lovers fraternity today as the current wet and windy weather carries on for another week before a marked cold snap with snow showers move South across the UK on the rear of a depression exiting the North Sea towards the middle of next week. The following ridge brings frosty weather for a time before Low pressure on a much more Southerly track at Day 10 throws up a heady mix of rain, sleet and snow to the South of the UK by the end of next week in temperatures below average for all by then.

http://www.meteociel.fr/modeles/ecmwf.php

ECM 10 DAY MEAN The 10 day mean chart must have little support from it's other members as the Mean Chart for 10 days today illustrates a lot of Low pressure over or near to the NW of the UK with the Jet Stream still strong but well South of the UK with rain and showers for all and cold enough for snow too at times on the hills despite a general Westerly flow being maintained.

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

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The models this morning continue to endorse the trend shown yesterday of the Atlantic under complete control of the UK weather over the next two weeks with a tendency towards colder conditions later as Low pressure and the Jet Stream drift somewhat further South than currently.

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 GFS and UKMO at 99.5 pts each.  At 3 days ECM is leading with 97.6 pts to UKMO's 96.9 pts while GFS lags behind at 96.7 pts. At 5 days ECM leads with 90.4 pts to GFS and UKMO at 88.6 pts each. Then at 8 Days ECM has taken over the leading spot from GFS with 67.7 pts to 67.1 pts. Finally at Day 10 ECM is ahead of GFS at 48.8 pts to 48.3 pts respectively. 

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  More variation of the same pattern from the models today as the UK continues to be pummelled by a very strong Jet Stream crossing the Atlantic and crashing into the UK. All areas continue to be at risk of more rain, possibly disruptive at times especially over upland areas of the West and North. While as always there will be some areas that fair rather better than others with the South and East seeing the best of any drier and brighter periods. While temperatures overall should not present widespread problems in between weather systems some colder air may tuck in sufficient to give rise to a slight frost and indeed some wintry showers over the hills. Looking into the second week the models play around with different evolutions still based around an overall potentially wet and windy theme. the main thoughts are that if anything Low pressure will dig even deeper into the UK with more cold air entrained within the depressions airflows over the UK with more in the way of snow on hills at times. The ECM Operational at the end of it's run shows hints of something quite wintry late on and although a little isolated in it's projections shows what can happen when the Jet Stream moves South of the UK as it's predicted to do later next week. So while I still can't offer any particularly cold winter weather again this morning the model runs are far from boring and while rain, strong winds and fluctuating temperatures remain the theme for the foreseeable I think there is enough support for the elements to throw up at least the chance of a snowy surprise here and there longer term especially over the higher ground.    

Next Update Thursday January 28th 2016 from 09:00

Edited January 27, 2016 by Gibby

[Daniel*]

Engaging output from ECM this morning with a low diving/sliding  into Southern Europe - propping up +ve heights to the NW thereby leading to the floodgates being opened potentially from the E. I'm surprised it is not more busy in here. A definite cooling down to seasonal to below average values from next week seems to be illustrated by the models.

Edited January 27, 2016 by Earnest Easterly*

[Singularity]

As much as the amplification trend makes sense, caution is well advised in light of the usual threat of complications;

The way GFS trashes the potential is with a shortwave hanging out to the west of Iceland, which brings back memories of what shortened our last cold spell. So it seems very plausible - BUT if you run the output from +114 to +150 you'll see that this feature sits there with hardly any movement, which is a little odd. Be it a cause or symptom, the jet stream doesn't develop the break we need to separate the low heights associated with the polar vortex to our E/NE from those associated with that U.S. low nearing the Atlantic days 6 to 7 - the one I've been keeping an eye on for a couple of days now.

 

So what of the Euros - well, fair to say they've been consistent for the past few runs with clearing LP to the east of the UK days 5-6 without leaving anything behind in the mid-Atlantic. We then look to that U.S. low and how it fares against the emerging Arctic High to determine the longevity of the mid-Atlantic ridge.

It does look like a race between the low and the high to stake a claim over the area NW of the UK via Greenland. ECM and UKMO have a faster build of heights from the Pacific to the Arctic via Alaska and that does the trick as far as I can see. Even at +120 the differences between GFS (left) and UKMO (right) are clear:

 

Given the origin of the ridge to the Arctic, the MJO behaviour seems likely to be very important here. I expect GEFS continues not to see as much of a signal as ECM and UKMO (this won't be proven by the forecast plots until late this afternoon).

 

Now how about that low tracking just north of the Azores on the ECM run... this is actually a nod toward one of the GEM runs yesterday, the 00z I believe. The feature becomes evident around +120 but while the other models either dissipate it (okay for a good northerly but less precip chances for the south) or merge it with the U.S. low (not helpful for sustaining the mid-Atlantic ridge), ECM seems to find some favourable upper level winds - a weak jet undercutting the the mid-Atlantic ridge - which allows the low to develop and move due east with interesting results. This seems a very 'particular' outcome, requiring a specific combination of factors to take place, which makes it seem a low probability outcome. Being on the ECM at +120 does make it worthy of a seat at the table of options, though.

 

I may as well finish up for now with a snapshot of GEM at +240. This run behaves like yesterday's ECM 12z but is a lot more chaotic with the vortex ending up as messed up as I've ever seen. It seems a bit over the top in that regard! The transfer of low heights across the Atlantic from NW of the UK also seems overly dramatic.

Why bother posting this, you may now be wondering - let's just say it demonstrates the effect on the models of there being no stable vortex position. I am encouraged that the key developments by ECM and UKMO are at only +120 hours, though.

[nick sussex]

Quite a split this morning between the GFS and the Euros. Generally when the GFS output shows the flattest solution you'd expect it to backtrack towards the others as its a known bias in its operationals aswell as the GEFS.

Reading NCEPs comments this morning they do expect some renewed amplication at least for a time and a strong warming trend for the eastern USA this would correlate with more amplitude over the central USA.

So at least we might see some move from the GFS towards the Euros.

In terms of cleanest transition to a possible colder nw flow the UKMO has this at T144hrs, the ECM is more complicated because of that low in the Atlantic and so to get to the more interesting part of its output has  less margin for error .

 

[northwestsnow]

GFs is being very stubborn with its flat prognosis,its either very stubbornly wrong, or its going to be the euros swinging round to the flat outlook.

[nick sussex]

12 minutes ago, northwestsnow said:

GFs is being very stubborn with its flat prognosis,its either very stubbornly wrong, or its going to be the euros swinging round to the flat outlook.

It has made some move towards the Euros with the PV close to splitting at T150hrs. Normally the GFS tries to backtrack slowly hoping people won't notice! Lol

 

[Ravelin]

So what do we have for early hours of Monday....

ECM has a well developed low to our NW, but separation between the remnant low heights over Greenland.

UKMO also has that separation  but a less well developed low.

GFS 0Z has less well developed low and no separation

GFS 6Z just rolling out has a well developed low and no separation

The conclusion....the models don't have a clue? I know I certainly don't!

 

Edited January 27, 2016 by Ravelin

[northwestsnow]

6z looks worse than the 0z and thats saying something.

Certainly nothing like the euro models.