Model output discussion - 20th Feb onwards

[knocker]

A shortwave forming south of Iceland Thursday 0z Swings south to be over the UK 12z Friday. Very wet.

A short lull before the next system wings in on the jet which is swinging around the HP arrives on Sunday. Very wet and windy.

That is the story according to the GFS

Be afraid, be very afraid.

Edited April 25, 2016 by knocker

[049balt]

Is this the Azores High that we all been waiting on, another week of Winter to go and then.

Edited April 25, 2016 by 049balt

[knocker]

The ecm is not actually much different to the GFS for the weekend but the difference is significant. It runs the shortwave SE into Scotland on Friday 12z so a pretty wet and windy day for most. It then builds the HP from the SW and this ridge zaps the system rushing in from the west before it hits the UK so ridging is just about the order of the day. This is knife edge stuff and a beady needs to be kept.

[Milhouse]

Good signals emerging for a possible southeasterly to develop later on. Very much like May 2008.

 

 

Edited April 25, 2016 by Milhouse

[Summer Sun]

The high is getting closer on ECM just can't quite manage it just yet

Has its first go on Sunday and Monday settling down for a time in the south and a bit warmer than of late

Remaining fine in the SW but a northwesterly flow sets up on Tues and Weds

The high then edges across the UK

So next week is an improvement certainly in the south and southwest with temperatures here closer to average further north it still looks chilly, but temps gradually rising compared to this week as we cut off the arctic flow nights remaining cold, but by day it will be fairly pleasant just about anywhere if you can get some sunshine and shelter

[Scorcher]

Under normal circumstances there would be little to cheer in these charts for warm fans but there are slow signs of improvement from the ECM.

In all honesty though, it can't get much worse than it is at the moment. Some of the most unpleasant weather I've experienced in late April. Time to turn the heating off soon surely?

[knocker]

There is not a complete agreement between the anomalies tonight in the 5-10 range which quite possibly explains the disagreement between the ops. It essentially involves the position and orientation of the upper trough and thus the influence exerted by the Azores HP.  NOAA and the GEFS favour a low pressure WNW flow bringing systems and unsettled weather into the UK whilst the ECM brings the HP much more into play which would certainly bring drier weather into the south of the UK. This wouldn't impact greatly on the temps which, although rising slowly, still a little below average.

In the 10-15 period although they more or less agree with a trough mid Atlantic. the upper flow varies between W and SW basically because there is a major difference between the GEFs and ecm regarding a trough or a ridge Scandinavia. Best left for the moment but all one can say the temps no great shakes but nearer average.

Edited April 26, 2016 by knocker

[knocker]

The GFS this morning does not fill one with cheer for the weekend

The Shortwave duly develops south of Iceland late Wednesday and tracks SE to be over Scotland Friday 00z. Could well be some extensive snow over Scotland and down to N. England. As this moves into the North Sea some very brief ridging behind before the next system blows in on a quite powerful jet in the early hours of Sunday bringing more wet and windy weather. This slides away SE, due in fact to the upper trough curving SE into N. Africa with a block away to the NE around N. Scandinavia.

But this is not all. The next system quickly rushes in and is 979mb just north of Scotland by 00z Tuesday bringing strong winds, perhaps severe gales in Scotland. This is as yet someway off so obviously will be subject to revision in the next couple of days. All in all not good.

The EC32 means update also has the upper trough running from the NW of the UK SE down through the North Sea into N. Africa with the block away to the NE and the Azores HP to the SW of the UK. This analysis then proceeds to change quite rapidly and by the 9th the block to the NE has gone and there is a trough in the eastern Atlantic with the upper flow from the SW and temps around average.

Edited April 26, 2016 by knocker

[knocker]

The ecm treats the Friday low in similar fashion to the GFS but is still making a bit more of the ridging after in moves into the North Sea. It does stillt rack the next system in but it's a weaker feature as it crosses the UK. Still wet and windy though. Fine margins but at the moment it's looking like a pretty unsettled weekend with Saturday being the best day.

It is also tracking the next system north of Scotland bringing some strong winds to that area.

Edited April 26, 2016 by knocker

[mountain shadow]

ECM op keen to build in high pressure from the South West at days 9/10 though knocker. 

Hopefully some support from the anomalies later.

[mb018538]

Hanging on to the hope that ECM building the high in towards the end of next week is the correct solution....could turn out nice if it drifts across us and drags something from the SW/S/SE. Maybe high teens with some luck!

[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 TUESDAY APR 26TH 2016

THE CURRENT GENERAL SITUATION A cold Northerly flow will back towards the NW tonight and tomorrow with a very showery airflow across the UK being maintained and with troughs developing in the flow later tomorrow moving NW to SE across Britain.

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

CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The UK sees very low uppers across the UK still with little sign of any significant change in the coming days. The freezing level will remain around 1700-3000ft through the next few days with snowfall expected across modest hills UK wide on occasion over the coming days.

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

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

MODELS-2 WEEK HEADLINE Remaining rather cold and showery this week but possibly becoming less cold next week.

THE GFS JET STREAM FORECAST  The Jet Stream is streaming South down across the UK today but will back more towards a West to East motion still across the UK later in the week. The flow remains quite well South over the remainder of the run but after a period of blowing quite well defined East or SE across Southern Britain becomes much less well defined later next week.

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

GFS OPERATIONAL The GFS Operational Run today shows a cold and showery Northerly flow blowing down across the UK between High pressure to the West and Low to the East. As the rest of the week progresses the winds will back towards the NW or West with further rather cold weather though perhaps not quite as cold as currently. through this period very showery conditions look likely with wintriness anywhere at first but more prone to Northern hills by the weekend. Then through next week and beyond very slow improvements take place as High pressure slowly builds across the UK with sunny and warmer days eventually but with a risk of night ground frosts remaining until very late in the period on this run.

GFS CONTROL RUN The theme of the Control Run is very similar to the Operational today with the cold and showery theme gradually giving ground from the weekend though the weather looks like remaining unsettled and breezy well into next week before the main improvement arrives from the SW and West. By the end of the run pressure looks higher well to the Northwest and with Low pressure to the South there may be a return of some showery rain towards the South and SW at the end of the period though by then it would probably be much warmer. 

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  It's been a very long time since the Clusters have given a clear and concise clue as to what weather pattern will lie across the UK in 14 days from the present and today is no exception with the bias supporting Low pressure to the South or West of the UK holding the biggest share of members though it has to be said there are several other themes in contrast to the above shown too.

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 still looks rather cold and showery through this weekend with modest and slow improvements towards a move away from the coldest conditions but still quite showery weather looking likely over the bank Holiday weekend in a blustery West or NW wind.

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

THE FAX CHARTS The Fax Charts today maintain a complex look this morning with an increased threat of troughs swinging in from the NW or West later this week and into the weekend which although rising temperatures marginally from current levels continue rather cool and unsettled conditions for quite a while yet.

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

GEM GEM this morning looks generally unsettled throughout the period this morning. In addition to the continuing threat of showers the winds backing Westerly will eliminate the very coolest conditions but with gales possible in places next week especially under deep Low pressure over the North the weather will be hardly likely to feel particularly Springlike on any day through this run with rain or showers at times.

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

NAVGEM NAVGEM today looks like maintaining rather cold conditions under a NW flow for much of the next week. With Low pressure in close proximity of the UK the weather will be showery for much of the time but with some drier periods too and with some longer spells of rain mixed in too especially over the North where snow could continue to fall over some of the higher hills despite being May by then. 

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

ECM ECM is the once more the most optimistic model this morning in that while it also shows a cold and showery week to come conditions slowly improve at the Bank Holiday Weekend as the cool and showery theme becomes replaced by less cold and benign conditions in the South although any major improvements look tentative at best as pressure remains Low to the East and also to the North of the UK with the best conditions likely over the South.

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

ECM 10 DAY MEAN (12z) The 240hr mean Chart from last night shows a High pressure ridge to the South of the UK with a Westerly flow across the UK. With the Jet Stream further North than recently near Scotland the South could become largely dry, less cool and bright whereas the North and NE continue to see cooler conditions with some rain or showers at times due to Low pressure belts to the North and East. 

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

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The models continue to show a steady improvement away from the very coolest conditions as winds back westerly. there is much disagreement though about how dry such a Westerly flow will become.

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 99.5 pts and GFS at 99.3 pts.  At 3 days ECM is leading with 97.3 pts to UKMO's 96.6 pts while GFS lags behind at 95.5 pts. At 5 days ECM leads with 89.1 pts to UKMO at 86.8 pts and GFS at 83.1 pts. Then at 8 Days ECM has the leading spot from GFS with 62.9 pts to 54.6 pts. Finally at Day 10 ECM has the lead from GFS with a score of 45.5 pts to 37.4 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 is still a quite muted approach to improvements within the models this morning but we may have to be very patient to see it. Through the rest of the working week there looks like a lot of bright and showery weather for all areas complicated by frontal systems swinging in from the NW on Wednesday night and Thursday with some more extensive rain and maybe even snowfall across the hills.. Then it's back to cool NW winds and sunshine and showers across the weekend and though it maybe a little less cold in the South conditions for the Bank Holiday weekend look unlikely to be warm anywhere with some fleeting sunny spells between the showers. Then as we look forward to the first week of May conditions look like improving very slowly with the South looking best for conditions as we  move deeper into May as the Jet Stream moves further North and pressure rises somewhat to the South keeping winds in a rather warmer westerly source. However, there is some dispute between the output on this solution with some resistance to any marked build of pressure with a more mobile Atlantic regime setting up with rain at times for all in a more unstable Westerly flow. I'm afraid we need more runs before the deeper outlook period comes better into focus with the  general theme of cool and showery weather continuing to be the main theme with the tentative rise in pressure and temperatures the most likely theme still over the next week at least. 

Next Update Wednesday April 27th 2016 from 09:00

[knocker]

I see that quite a few Hail Marys are being uttered this morning regarding the latter end of the ecm run. The is nothing that I can see that suggests that this isn't just transitory and brief at that. Nothing in the Anomalies suggests otherwise, including this morning's GEFS. More to point the EC32 has brief ridging at day ten which quickly gives way to an Atlantic trough by the 8th with a SW upper flow with temps nearer average.It looks very much like an unsettled zonal flow for the near future once this week is out of the way.

I am of course, as always, open to different interpretations.

 

Edited April 26, 2016 by knocker

[johnholmes]

I would tend to agree overall with that view mr K, the 8-14 NOAA anomalies suggest a slacker more westerly flow but there is, as yet, no sign of any significant warm up other than an occasional day in the 8-14 day range.

[knocker]

The EPS 10-15 this morning is also in the slack westerly zone, briefly indicating the HP pushing a little further NW around 8-18 thus veering the winds a tad, and generally slowly rising to around average. As you say John no significant warm up within this range. I'm getting more depressed by the minute vis the prospects for May.

Edited April 26, 2016 by knocker

[mb018538]

May is a transient spring to summer month anyway, it's if we start getting loads of low pressure and NW'erlies through the 10 or so weeks of 'high summer' (June, July and the first half of August by my very loose definition) that we can all get depressed! Average in May won't be too bad 

[Nouska]

2 hours ago, knocker said:

The EPS 10-15 this morning is also in the slack westerly zone, briefly indicating the HP pushing a little further NW around 8-18 thus veering the winds a tad, and generally slowly rising to around average. As you say John no significant warm up within this range. I'm getting more depressed by the minute vis the prospects for May.

I think I am too...   

All through winter, the CFS was very emphatic on the positive anomalies vanishing by April - they did not go as far as to show any great negative anomaly but the placement pointed to a flow from the NW to SE. This is what we are seeing in the modelling and prospects do not look like changing before mid May. 

The bright side - the drought restrictions of last year are long gone and in a much better position if a long hot summer awaits.

[knocker]

Indeed and July is on the up and no cold SST anomaly

Edited April 26, 2016 by knocker

[johnholmes]

Not how UK Met currently see it, by summer end the -ve anomaly in the Atlantic off western Scotland has retreated west but it is still showing even then?

http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/glob-seas-prob

[Nouska]

19 minutes ago, johnholmes said:

Not how UK Met currently see it, by summer end the -ve anomaly in the Atlantic off western Scotland has retreated west but it is still showing even then?

http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/glob-seas-prob

I noticed that but the EUROSIP (amalgamation of MF, ECM, UKMO and NCEP) have the cold pool dissipating by end of August. Perhaps the addition of the NCEP component is helping lessen the negative anomalies of the other agencies.

Interestingly, the cold pool reappears by October - does this indicate a calm anti-cyclonic picture over the summer Atlantic and as soon as autumn storms stir up the surface, the cold resurfaces?

EUROSIP for August and October.

  

 

[knocker]

Now don't go suggesting a mild westerly regime for the winter Nouska or the sales of Prozac will go through the roof.

[phil nw.]

The combined London Ens.graph from the 00z run certainly underline how depressed the 2mtr temperatures look as we head into May.

struggling to get maximums towards even the mid-teens is no great shakes.

All eyes to the south west hoping that the Azores high pokes his nose this way but no real sign that he will pay us a visit any time soon.

Day 10 ECM/GFS means  

The jet tending to remain too far south with Atlantic systems never far away so currently no signs of any settled and warm spells.

 

 

  

 

 

[knocker]

The GFS 06 swinging the Iceland low over Scotland Friday morning and then nudging the HP in.

[mb018538]

GFS 12z is a total nightmare....look away!!

[Summer Sun]

UKMO showing some improvements Sat and Sun nothing especially warm but more settled

Before a deep low centered between Iceland and northern Scotland turns BH Monday wet and windy especially for the north

Edited April 26, 2016 by Summer Sun