Model Output Discussion 12hrs. 01/10/13

[Captain Shortwave]

what's happening here then.

Undercut incoming?

I need a drink, preferably a double scotch 

Edited October 5, 2013 by Captain shortwave

[AWD]

As was probably likely, the UKMO 0z run is slowly but surely moving towards something akin to recent EC Det output;image.jpgI think it's rather likely now that the outlook is above average rather than below average for 99% of the UK, 99% of the time. A little premature excitement with regards to cold me thinks last night.GFS Op, FWIW, similiar for the foreseeable.

Now I look stupid so I'm off to the Cafe for a fry up now!

[Frosty.]

Now I look stupid so I'm off to the Cafe for a fry up now!

I'm waiting for the Ecm 00z ens mean the fat lady isn't singing yet but shes hovering behind the curtains

[Scorcher]

I probably wouldn't go that far Karl. very surprised to see the ECM's about turn this morning- a very nasty and unexpected surprise but only one run at the moment- the GFS looks good again this morning. The only saving grace for the ECM 00Z is the end of the run when it starts to warm up again. If the run did happen we could evntually end up with a similar setup to what it was showing last night for next week, only a few days later at least. 

Edited October 5, 2013 by Scorcher

[smithyweather]

Oh good -4c uppers. Lets hope it verifies so we can get our first frosts and snow. I would like a swift,fast transition to winter.

[MR EXTREMES]

from the model perspective theres all sorts across the models and each have there own idear I think by Tuesday were have a clearer picture but does still look high pressure dominated with southerlies sw westerlies northerly as heights wobble about I don't think any model knows what to do with all this high pressure.

but little more time and were get a clearer picture.

but overall nice week coming up beyond I punt for a rather cloudy but average temp wise slowly decreasing temps more so at night under clear skys.

[bluearmy]

ecm 00z op would be an outlier on previous ens runs so seems very unlikely. no surprise to see the higher resolution of this model overdoing the signal. the message is there - you just need to look through the obvious stuff to see it.  happy to take ukmo 00z as a decent point of ref for now.

[No Balls Like Snow Balls]

What a beautiful chart. Nice fresh and cold air covering the whole of the country.

 

 

daytime temps of singe digits in the North and low double figures in the South?

 

 

[Radiating Dendrite]

I would imagine single figure max in the South too, especially if we get chilly nights.

[MR EXTREMES]

What a beautiful chart. Nice fresh and cold air covering the whole of the country.

 

ECM0-120.GIF

 

daytime temps of singe digits in the North and low double figures in the South?

whats intresting is if this does happen a fella in the winter thread posted a video which was rather intresting and had said a cold blip mid October I wonder if hes right.

to be honest it could of been posted in here but might result in more of cold vs warm discussion instead of model but just might be intresting to some.

[East_England_Stormchaser91]

Out of nowhere, signs of some northern blocking are beginning to occur! 

Isn't this how 1963 started, hints of it were given by a few cold snaps prior to it in Autumn. And Euro/UK high retrogressed North to Greenland, very similar to what this looks like it could well do.... interesting 

[Captain Shortwave]

Oh good -4c uppers. Lets hope it verifies so we can get our first frosts and snow. I would like a swift,fast transition to winter.

There wouldn't be any snow on those charts, in fact even frosts would be quite limited to high ground and patchy stuff elsewhere. Most of the precipitation will end up in the south east where it will be entirely of rain. This is the beginning of October, not November.

Frankly the ECM is terrible for my location, 10C with lots of cloud and outbreaks of rain on and off for several days. 

 

At least the NAVGEM has also changed sides

Definitely not clutching at straws 

Edited October 5, 2013 by Captain shortwave

[Polar Maritime]

There wouldn't be any snow on those charts, in fact even frosts would be quite limited to high ground and patchy stuff elsewhere. Most of the precipitation will end up in the south east where it will be entirely of rain. This is the beginning of October, not November.

Frankly the ECM is terrible for my location, 10C with lots of cloud and outbreaks of rain on and off for several days. 

 

I understand not everyone's cup of tea... But at least there are signs of Autumn in the charts at long last. 

[Summer Sun]

So this morning UKMO and ECM are going along the same route with a northerly later next week for a short time

 

 

Before the high edges back east

 

 

UKMO looks slightly further east than it was yesteday to me

 

 

Before the high sits right over the UK at t144

 

 

GFS continues to say no to any northerly

 

 

which is backed up very nicely by its ensemble

 

[Summer Sun]

Latest from Gibby, high pressure likely to dominate the UK weather in the coming two weeks

 

Good morning. Here is the report on the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Saturday October 5th 2013.

 

All models show a build of High pressure over the South of the UK over the next few days while Northern areas remain under a fairly weak West or SW flow with a weak trough edging SE through Scotland and Northern Ireland to rest over Northern England tomorrow with a little rain in places as it moves South. With very light winds and some clear overnight skies the South becomes at risk of mist and fog patches in light winds.

 

GFS then shows this pattern continuing at the start of the new week with the North still at risk of a little rain for a time before all areas become fine as High pressure rebuilds to the NW sinking SE. The risk of fog increases midweek for all before a freshening SW wind again over the NW brings a renewed risk of occasional rain over next weekend. The second half of the run suggests a North/South split in the weather developing with windier and more changeable conditions with occasional rain at times in the North in brisk West or SW winds while Southern areas maintain a lot of dry and fine weather with some warm sunshine by day and patchy fog at night in temperatures still well above average for October.

 

UKMO today also shows the changeable conditions in the North to start the week giving way to nationally fine and dry weather from midweek as an intense anticyclone develops over the UK with fine and dry weather with near average temperatures by day but with such stagnant air mist and fog could become a widespread, dense and disruptive issue late next week which would become slow to clear in the mornings. Where it persists the rather cold nights would extend through the daytimes too.

 

GEM also shows a similar UK based High later next week with fine and dry conditions with mist and fog problems night and morning. Later in the run it slips the High away to the SE but always maintaining a ridge up across the UK with fine and dry weather continuing with some warm sunshine developing outside of any persistent fog. With a Continental drift to the wind any sunshine in the afternoons would lift temperatures well above average.

 

NAVGEM has High pressure moving slowly off shore to the East of the UK later next week with a warm South or SE flow developing late on but only the far West coming under risk of any rain as troughs move in close next weekend. Mist and fog at night could be an issue midweek, gradually lessening under a freshening breeze later.

 

ECM today shows a somewhat different scenario with High pressure building north next week replacing the Westerly winds in the North with a Northerly then NE flow later in the week. Much cooler air would be fed South across all areas midweek with some showers in the SE late in the week before High pressure establishes itself over the UK late next weekend and the start of week 2. The air is much cooler than the other models show which would support even slower clearances of overnight mist and fog as well as introduce the chance of some frost at night with daytime temperatures dependant on whether the fog clears or not. If it does some afternoon sunshine could raise temperatures to average in light winds.

 

The GFS Ensembles support another week of above average uppers translated down to the surface too for much of the time as winds occupy themselves from a Southerly aspect. In week 2 a slow decline in temperatures is supported with the incidence of rain shown on the increase as well. having said that a fair amount of dry and benign weather is also shown for many members through Week 2 too.

 

The Jet Stream today shows the flow almost having realigned to the NW of Britain where it is maintained over the coming week in response to a build of High pressure near the UK. It does trend further South and East across Britain in Week 2.

 

In Summary it's High pressure that is likely to dominate the UK weather in the coming two weeks. There are differences between the outputs in the positioning of High pressure which would have profound differences on the weather at the surface. Most models support high pressure drifting East or SE next week which would feed up some more Continental Southerly winds between areas of night time mist and fog whereas UKMO and ECM draw down some cold air from the North midweek with High pressure becoming immersed in rather cooler uppers. This would mean that after a warm start to next week cooler conditions, again with widespread and this time cool nights with dense fog, slow to clear in the mornings look likely. The air could be cool enough for some frost to form in places overnight, this more likely where it isn't foggy. Whichever way you look at it the chances of anything wet and wild is still an age away this morning with the rather benign mid Autumn period continuing for the foreseeable future

 

http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm

The ECM ensemble doesn't quite support the northerly

 

 

Op

 

[Captain Shortwave]

I understand not everyone's cup of tea... But at least there are signs of Autumn in the charts at long last. 

The issue is here, if we had the same charts in November where high pressure was over us, no one would bat an eyelid. Just because it feels warm doesn't mean it's not Autumnal.

Given that at this time of year widespread snowfall is very unlikely and that temperatures can still reach close to 80F shows that this pattern isn't entirely unseasonable by UK standard. It just feels like double standard that people will detest a set up which shows warm and sunny weather but cheer virtually the same chart just because it's 5-10C cooler. What's worse is the pattern would probably be even greyer and more boring than the warm counterpart.

ECM mean looks similar to the UKMO. I guess you put the ECM ens in the same boat as the GFS here, that's a huge swing in one run.

Edited October 5, 2013 by Captain shortwave

[Summer Sun]

Long term the ECM ensemble remains settled

 

 

Basically its as you were from the ECM ensemble

[Polar Maritime]

Morning Captain, I think it's the anticipation for some, but the transition in the sett-up we are in, between a pattern change, will always bring some kind of gloom for some before it takes hold proper.

Edited October 5, 2013 by Polar Maritime

[draztik]

And out of nowhere, we could be edging towards single digit daytime temps midweek if the ecm verifies... I think ill put the bbq plans on hold lol

[Frosty.]

The met office T+120 fax chart and ecm 00z op are remarkably close, even though they are probably going to be very wide of the mark but something could be brewing beyond the pleasantly warm settled spell.

[Captain Shortwave]

I guess so, at least if something like the UKMO verified it would clear the low cloud out of the way and there might be some decent weather with chilly nights. I do kind of wish the retrogression and high latitude blocking signals held off for a couple more weeks for when it could deliver some proper winter goodness.

Morning Captain, I think it's the anticipation for some, but the transition in the sett-up we are in, between a pattern change, will always bring some kind of gloom for some before it takes hold proper.

It's nice to see them there to show it's possible, I just hope we don't peak too soon on this signal because the last thing anyone wants is for a month of polar blocking during a time where snow is still very hard to get at low levels.

@Draztik

 

And out of nowhere, we could be edging towards single digit daytime temps midweek if the ecm verifies... I think ill put the bbq plans on hold lol 

Nah we British have handled worse BBQ conditions, like virtually every wet summer weekend 

Edited October 5, 2013 by Captain shortwave

[Summer Sun]

If its colder air you want the ECM Op run is for you this morning for a time

 

 

If not the ensemble run is slightly warmer

 

[Scorcher]

A very deflating morning if you are one of the people who would like some warm sunshine while we can still get it- fingers crossed that the high will eventually drift east in any case and bring up warmer air. Even if this doesn't happen though, the one saving grace for the mildies could be that this warms up Eastern Europe for a time and makes conditions less conducive to cold later on. Fingers crossed whatever happens.

[Nick F]

Bit of a shock from the ECM, and its cool northerly flow with showers in the north and east from late Wednesday onwards not without support from the 50 EPS members and ENS mean from the 00z:

 

http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!132!pop!od!enfo!enplot!2013100500!!/

 

http://www.ecmwf.int/products/forecasts/d/charts/medium/eps/ensm/essential!Geopotential%20at%20500hPa!Europe!120!pop!od!enfo!plot_ensm_essential!2013100500!!/

 

00z GEFS gives no support whatsoever to the ECM deter. - rather it drifts HP east, so wondering whether this is one of ECM's rare wobbles. Think that northerly would be shunted further north and east if the ECM did carry on in a similar vein with the wave pattern.

[Tamara]

Long term the ECM ensemble remains settled

 

 

Basically its as you were from the ECM ensemble

 

The ensemble mean tells us very little about what is going on atm. As suggested yesterday there is a whole variety of suggestions in the mix, even if the High does end up close to the UK in terms of position and orientation. However, even this is less certain this morning as the trough to the NE has fast become a much big player in the model output than a day or so back. The EPS members are a dogs breakfast this morning from day 6 and 7 - which rather underlines the meaningless chart(s) of that ECM ensemble mean.

 

There is now good agreement for the trough to sink through Scandinavia - as per the fax chart f.e, but the degree of amplification is still very uncertain and hence anything from a UK High to a chilly north or north easterly is possible - or even the pattern flattening and the high sinking to return us to the NW/SE split.

 

Its not worth taking any model output at face value atm, therefore a very uncertain outlook for later next week

Edited October 5, 2013 by Tamara תָּמָר