Model Output Discussion - 1st February Onwards 12z--->

[bluearmy]

The GEM hinted yesterday that all may not be so rosy in next weeks garden and the ECM took up the mantle. The 00z ops continue the trend.

possibly a repeat of the failed feb settled period though less of a fail (if you get my drift)

[Captain Shortwave]

Lots of posts about the milder Sunday but its not all mild on the ECM and GFS only has a brief flirtation over the weekend.

Not quite true with respect to the GFS, England and Wales see temperatures in double figures and at times the mid-teens throughout high resolution (though the north does turn briefly cooler Sunday into Monday, despite winds veering south easterly at times, in March a high to the north east doesn't always mean cold weather.

So it's the GFS vs the other models this morning, the GFS keeping the UK settled and rather mild for ost of the time whilst the ECM keeps a more changeable theme.

GFS

ECM

 

UKMO

 

GEM

 

The UKMO and GEM agree with the ECM on the more changeable solution as low pressure pushes through the north of the UK.

[Frosty.]

The GFS 00z op run shows a prolonged spell of generally very mild / rather warm conditions across southern UK with maxima nudging into the low 60's F at times and high pressure tries it's best to settle the weather down but further north by northwest it's generally cooler and more unsettled at times.

Edited March 4, 2015 by Frosty.

[IDO]

The charts have been great but I have been sceptical of this initial pressure builds longevity, due to the general mobile pattern, with the PV running a zonal route to the north of the UK. There is always a risk that lower heights will encroach south, as higher pressure cells migration timings allow. I am more confident during early week 2 of a pressure build, due to the PV becoming more elongated from its current circular shape, as this will ease the zonal flow. However the pattern looks mobile (PV) even at D16, so the absence of any blocking remains, as it has during the winter.

 

The London pressure charts show some members jumping ship from around D5-8, though they do recover afterwards:

 

 

The mean at D7 shows the period where there lower heights may make progress: 

 

The weekends high pressure cell moving into Europe (after D5) and the following high pressure cell in the SW UK bound. The models will play with how far south the jet slides and as there is only a few hundred miles difference in outcomes between a warm sunny ridge or more unsettled jet driven wetter period, it is really down to luck. The long wave pattern looks agreed between the models, just the mesoscale details and to the position of the jet to sort out.

 

The D10 plus mean is convincing for a mean high to our east slowly sinking to the SE:

 

D10:   D12: 

 

D16: 

 

The GEM means are similar (12z): 

 

That sort of high is more likely to amount to milder than average temps than below average.

 

Hopefully the GFS op is correct this time (another mild settled run), but with its apparent bias, I suspect the jet will be further south.

 

 

 

 

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS.

 

THE CURRENT GENERAL SITUATION A ridge of High pressure will move East across the UK today followed by a strengthening SW flow across Northern areas tonight and all areas tomorrow.

 

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

 

MODELS-2 WEEK HEADLINE A lot of dry and reasonably mild weather with some sunshine in the South and East but occasional rain possible at times especially over the North.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream Ensemble Forecast shows the flow in the process of change. It's axis will become more SW to NE in a position much further North than recently lying somewhere between Scotland and Iceland later with a deep trough setting up over the mid Atlantic.

 

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

 

GFS OPERATIONAL The GFS operational today shows milder Atlantic SW'lies taking control soon as High pressure moves in close to the South of the UK and a deep Low pressure moves up towards Greenland pumping mild SW winds from the Southern latitudes of the North Atlantic across the UK soon. A trough of Low pressure will affect the North at times with a little rain. Through the run this basic pattern prevails with High pressure close to, over or just to the East of the UK warding off the worst of Atlantic fronts from all but the North and NW though the odd rogue one is shown to break through to all areas at times before pressure rebuilds. 

 

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

 

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

 

THE GFS CONTROL The GFS control run supports the operational well again this morning with High pressure always in close proximity to the UK, especially Southern parts with fine and dry conditions for the majority of the time. However, as with the operational there are occasional interventions of troughs giving rise to more cloud and a little rain before a resurgence of High pressure follows.

 

THE GFS CLUSTERS The GFS Clusters show a lot of High pressure domination within the pack this morning with the vast majority indicating a centre either over or just off shore of the UK with fine and dry weather largely prevailing.

 

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 UKMO this morning is more disappointing with the Atlantic looking too strong for any more than a brief spell of settled weather. A rain bearing trough weakens across Southern areas on Sunday with High pressure moved off to the East with a new depression swinging NE close to NW Scotland threatening further rain on SW winds for all for a time early next week.

 

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

 

THE FAX CHARTS The Fax Charts follow the raw data well up to Day 4 and 5 whereas the raw data shows a greater influence of Low pressure to the NW late on from that which was shown on the last night's 96 and 120hr charts.

 

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

 

GEM GEM too shows High pressure close to the South at times being squeezed away far enough on occasions to allow the influence of the Atlantic over the North to extend to all parts at times with some rain for all in the generally SW or West flow

 

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

 

NAVGEM NAVGEM too shows pressure falling off slowly next week as the High close to Southern Britain at the weekend migrates further East into Europe thereafter. A South or SW flow is shown to carry an increasing threat of rain from the West later next week.

 

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

 

ECM ECM this morning also shows a rather messy pattern developing next week as High pressure is shown to lose it's grip to small but significant Low pressure moving in to the NW from the Atlantic with some rain inevitably for all. The pattern evolves further into a slack pressure gradient across the UK with Low pressure ruling the weather as centres trundle in from the West weakening as they do.

 

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

 

ECM 10 DAY MEAN The 10 Day Mean Chart still shows a lot of High pressure domination this morning though over recent runs the axis of the ridge os being pulled slowly SE allowing more chance of a moist SW feed to affect at least the Northern parts of the UK..

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The drier and anticyclonic phase has been significantly reduced in both extent and duration this morning.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKM & ECM The current verification statistics for the past 31 days shows ECM leading the way at 3 days with 97.6 pts followed by UKM at 97.1 pts and GFS at 96.4. At 5 days ECM  continues to lead the field at 90.4 pts over UKMO at 88.3 pts and GFS at 87.1. At 8 days ECM remains the leader with 66.6 pts over GFS's 59.9 pts. Then at Day 10 ECM retains superiority at 49.8 pts over GFS at 42.4. 

 

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.prig

 

 

MY THOUGHTS The main theme of this morning's output is the watering down of the extent of High pressure across the UK next week. Most output suggests that the High will be less significant and dominant in halting the Atlantic bandwagon up and together with a less far north Jet flow next week than previously thought could mean occasional rain becoming a feature for many areas next week between the drier interludes still on offer. Although details are hard to pin down on specific weather events next week most output suggests at least weak troughs making it down into the South to make for grey and cloudy conditions and a little rain at times. Temperatures should not be too problematic maintaining average levels but the warmth of this weekend looks unlikely to last long at all if it indeed develops under the prominently expected cloudy skies. Winds will be mostly from a SW point and strong at times in the North tempering the temperatures still further. GFS together with it's cluster groups and the ECM 10 Day mean offer something much more settled for the UK as it's keener on High pressure more dominant and long lasting as well as milder temperatures but I would not bet against the Euro's operational's having a better handle on this and now that there is support outside of GFS for a more changeable phase to take shape next week I think it's pretty certain it will evolve albeit may be in different detail than that shown. So in a nutshell it's going to become less cold with a mix of dry, mild and bright weather with occasional interventions of cloud, wind and rain, most likely over the North but occasionally the South too with temperatures generally close to average or maybe a bit above in the brighter periods.   

 

Issued at 09:00 Wednesday March 4th 2015

[Midlands Ice Age]

Still seems the models are somewhat lacking accuracy in the 6day plus timescale. The new GFS hasn't helped here.

 

We are used to seing cold weather dissappear in the 5 - 7 days timescale, but now it seems as though this also applies to the 'milder' / warmer weather also.

 

I guess the problem is still modelling the placement and strength of the PV.

Edited March 4, 2015 by Midlands Ice Age

[Frosty.]

Without a shadow of doubt, the Ecm 00z ensemble mean is better than yesterday, especially for the south where it looks like becoming generally settled with pleasant temperatures and eventually northern parts of the UK see a considerable improvement. In the nearer timeframe, it's going to turn much milder with temps around 15 /16 Celsius 60F in a few days time.

[Frosty.]

Nice 6z on the whole, becoming v mild the further south you are, could even call it warm by early march standards. Lots of high pressure on the way, a few less settled days but for early spring it's very good with temps on some days reaching the low 60's F. :-)

[summer blizzard]

Much messier output from day 6 on all models. GFS makes little of that but has a second front at day 10, GEM builds pressure again from day 8 and the Euro is a stinker.

 

[Frosty.]

I have seen definite improvements in the Gfs and especially the ecm ens mean so far today, and even in the worst case scenario from the Gem 0z, beyond T+168 shows a big improvement, at least for southern UK. I'm more optimistic today that we will see a predominantly pleasant outlook with higher pressure than we have seen for several months, very good for farmers with their lambing and excellent for gardeners, the green shoots of recovery are almost here.

[summer blizzard]

For all the faults on the operationals the ensemble means are certainly stunning.

 

[shotski]

For all the faults on the operationals the ensemble means are certainly stunning.

 

For what exactly ? A south easterly with average conditions.

[summer blizzard]

For what exactly ? A south easterly with average conditions.

 

Likely above average maxima. Here in Leeds SE flow is probably the sunniest direction reliably.

[Frosty.]

I think it's good news from the models so far today, gem 0z is worst of them but even that massively improves post T+168..but the current expert view expects a generally settled spell to commence from around the middle of next week following a brief atlantic incursion. This is not to say there won't be the occasional unsettled blip along the way, but a large chunk of March is looking very springlike with temperatures often above average and with generally high pressure, the most anticyclonic spell since last autumn.

[Summer Sun]

GFS 06z ens looks settled for most next week

 

 

Maybe some patchy rain at times next week at first more so in the far north but on the whole it looks very settled cloud amounts are likely to vary but in any sunshine with light winds it would feel very pleasant

[Eugene]

Again it looks like any anticyclone over the country is pushed back again, ECM 00Z does look disappointingly cloudy after the clear blue skies of the past 3 or 4 days.

Edited March 4, 2015 by Paul

[winterof79]

Again it looks like any anticyclone over the country is pushed back again, ECM 00Z does look disappointingly cloudy after the clear blue skies of the past 3 or 4 days.

I agree,i do not see all this warm weather.The METO medium term has the rain word quite a few times.

Apart from Sunday there is no real warmth on offer other than in sheltered parts, out of the shade, if its not breezy.

Any high looks likely to set up to our East not slap bang on top.

Edited March 4, 2015 by Polar Maritime
To move discussion on..

[Frosty.]

The GFS 12z shows high pressure and Atlantic low pressure trading blows next week as HP battles for supremacy and it's the north and west which suffer, the south and east look generally fine and mild, between Saturday and Monday could see temperatures into the 60's F. Further into the run, high pressure delivers the knock out blow and the weather settles down. I agree with the met office here, the middle of next week looks like a pivotal moment for HP to win out, that's not to say there won't be further attempts from the Atlantic but to me the outlook looks very springlike indeed for most of the time. :-)

Edited March 4, 2015 by Frosty.

[mushymanrob]

Again it looks like any anticyclone over the country is pushed back again, ECM 00Z does look disappointingly cloudy after the clear blue skies of the past 3 or 4 days.

 

.... which is why you shouldnt look at any one run to build a case for either ramping nor dismissing anything. the anomaly charts strongly suggest high pressure will be the dominant feature of our weather from now until mid month. 'warm' of course is reletive and would suggest several degrees above average .... and that is likely for some areas (but not a countrywide event).

 

although the ecm anomaly doesnt suggest much in the way of high pressure, currently its an outlier, so writing off high pressure domination is premature and given the ecm's recent wild swings i wouldnt put too much faith in it being correct.

so some pleasant, or very pleasant, dry, days on offer with 'average' looking the worst case scenario, suits me!

[Captain Shortwave]

I agree,i do not see all this warm weather.The METO medium term has the rain word quite a few times.

Apart from Sunday there is no real warmth on offer other than in sheltered parts, out of the shade, if its not breezy.

Any high looks likely to set up to our East not slap bang on top.

High pressure east of the UK into week 2 looks likely 

backed up by the GFS ens

A flow from a southerly quadrant looks likely. Before then it looks like some wind and rain will push into the UK at times, especially the north, though southern areas look pretty dry with any rainfall being light as fronts fizzle as they move across the UK. Week 1 is a set up of ridges pushing north east through the UK and being pushed to our east, fronts push through before another ridge builds. The end game will come when low heights over the Med fill or get shunted eastwards to allow more robust heights just to the east of the UK.

I have to disagree with the brief mild comment. Very few days are average or below in surface temperatures. Most days are mild or indeed very mild. If a southerly flow does develop next week then it will feel pleasantly warm with temperatures in the mid-teens and this time there should be sunny spells with a drier feed of air (in fact southern areas will see temperatures in double figures for the foreseeable, cooler at times in the north).

 

The GEM throwing out some perfect summer set up charts today

Shame it's only March but it would be sunny and very pleasant with a flow between the south and east. (if it came off, which it won't )

Edited March 4, 2015 by Captain shortwave

[Eugene]

I agree,i do not see all this warm weather.The METO medium term has the rain word quite a few times.

Apart from Sunday there is no real warmth on offer other than in sheltered parts, out of the shade, if its not breezy.

Any high looks likely to set up to our East not slap bang on top.

 

 

Indeed and the cooler 850's from the northwest on Sunday are moving in much more swiftly than first thought on lots of ensemble runs and UKMO 12Z, GFS 12Z ensembles are all over the place too for next week, confidence must be very low for next week.

 

Anybody seen our friend from the Met Office?... Would love to hear his views for next week.

Edited March 4, 2015 by Eugene

[Frosty.]

The GEM 12z is gradually looking more settled next week, and v mild further south. I agree with mushy and CS, I see a generally mild to very mild outlook, at least for the southern half of the uk and I also think that after the Atlantic incursion early next week, high pressure will take control and become centred just to the east enabling a flow sourced from southern Europe, just think, in a month from now, a similar flow would see temps into the 70's F.

[Summer Sun]

ECM looking more unsettled than GFS and GEM again this evening

 

T168

 

 

GEM and GFS for comparison

 

 

If we move it forward to day 6 you can see the difference between ECM and UKMO, ECM develops that small area of low pressure over the north where as UKMO keeps the centre of the low north of Scotland thus pressure is higher for more of the UK

 

[Eugene]

Models firming up on a wet tuesday now, afterwards is very uncertain.

 

Edited March 4, 2015 by Polar Maritime
Some supporting charts would be vastly helpful, So i've added one.

[Frosty.]

IMO the Ecm 12z is better than the 0z and much better than yesterday, high pressure or at least ridging is present every day and although a shallow showery trough affects the north next week, the south is always close to HP to the south and the run ends more settled everywhere. Let's enjoy the big warm up in the short term with temps into the high 50's to low 60's F especially on Saturday and for the south on Sunday and monday.