Model Output Discussion 12hrs. 01/10/13

[Sweatyman]

Wow, that's the biggest northerly toppler I've ever seen.

seems like a warm front

[bluearmy]

Watch for an upper ridge becoming established n scandi as we approach months end. Naefs has been hinting at this for a few runs and now develops a weak high anomoly ..

[Jason T]

seems like a warm front

 

Warm front...That's the new gem, It''s very much pointing and showing a cold front up North, All models are the same ,Tease to please, Show an offering and then YOU end up being an outlier. Anyway back to the current models.

[Panayiotis]

The 12z CFS again showing a colder November, lets see if the soon to be updated 9month and 1month CFS charts for November produce anything cold. I will upload later if so..

 

[Cloud 10]

Watch for an upper ridge becoming established n scandi as we approach months end. Naefs has been hinting at this for a few runs and now develops a weak high anomoly ..

 

Plenty of upper ridging in this thread this evening. 

[Jason T]

Is it me,or is the whole intense cold scenario all East side (North Pole Global Stats Current), Canada, Greenland etc (West Side) has nothing really. Apologises if i sound stupid,But i do not re-call seeing this output since i joined. If the Jet sinks further South, I'm guessing we could be looking at a real special Winter set up.

 

[Frosty.]

I think there could be more drama tomorrow with that cold block heading towards the far northeast of the uk later next week. :-)

[Captain Shortwave]

The pub run has the 0C isotherm barely even grazing the north of Scotland late next week

Until you lose the heights over southern/central Europe then any cold is going to be fleeting and more of a north only event.

Edited October 12, 2013 by Captain shortwave

[damianslaw]

Interesting synoptics at present, the polar vortex locked in place over Siberia is certainly the key player over the northern hemisphere at present and is preventing low pressure from steamrolling its way into scandanavia thanks to higher than normal heights in the north scandanavia/east greenland regions.

 

The outcome is the development of a cut-off low scenario in the mid atlantic which I suspect is going to come unstuck by heights to our NE and conversely heights to our NW.

 

The models struggle in such set ups, and whilst UKMO and GFS this evening suggest more of a southwesterly airstream later next week with the low pressure just far enough north to prevent any undercut from the NE, there are hints from the ECM of a slightly more southerly positioned low pressure, which could easily enable a much colder feed to move down from the NE as the low heights enter the south of the country.

 

Keep an eye on developments to our NE in the days ahead - as it is developments in this direction which will dictate the weather for the latter part of the month. The jetstream is forecast to position itself on a southerly course again influenced by the position of the PV. There is a very fine line developing at the moment between cold and mild.

[Yarmy]

Is it me,or is the whole intense cold scenario all East side (North Pole Global Stats Current), Canada, Greenland etc (West Side) has nothing really. Apologises if i sound stupid,But i do not re-call seeing this output since i joined. If the Jet sinks further South, I'm guessing we could be looking at a real special Winter set up.

 

Been lopsided for a few weeks now, hence the early SIberian snowcover buildup. Some big cold shots going into N America later in the output though.

[Frosty.]

The pub run has the 0C isotherm barely even grazing the north of Scotland late next week

Until you lose the heights over southern/central Europe then any cold is going to be fleeting and more of a north only event.

True captain but I don't have much faith in the gfs 18z op run nailing the pattern for later next week, there are 20 other perturbations to choose from and every single one of them will probably be wrong too.

[Gaz1985]

Interesting synoptics at present, the polar vortex locked in place over Siberia is certainly the key player over the northern hemisphere at present and is preventing low pressure from steamrolling its way into scandanavia thanks to higher than normal heights in the north scandanavia/east greenland regions.

 

The outcome is the development of a cut-off low scenario in the mid atlantic which I suspect is going to come unstuck by heights to our NE and conversely heights to our NW.

 

The models struggle in such set ups, and whilst UKMO and GFS this evening suggest more of a southwesterly airstream later next week with the low pressure just far enough north to prevent any undercut from the NE, there are hints from the ECM of a slightly more southerly positioned low pressure, which could easily enable a much colder feed to move down from the NE as the low heights enter the south of the country.

 

Keep an eye on developments to our NE in the days ahead - as it is developments in this direction which will dictate the weather for the latter part of the month. The jetstream is forecast to position itself on a southerly course again influenced by the position of the PV. There is a very fine line developing at the moment between cold and mild.

 

Or it could all end in tears for coldies.

[Frosty.]

It won't end in tears for coldies in either oct or nov, any cold snap will be a bonus before dec 1st, I just hope we start to see a more active pattern through the rest of october. :-)

[AWD]

Or it could all end in tears for coldies.

I don't think anyone is going to be "crying" over the lack of cold in October. Lol.Autumnal weather in autumn is what the NWP show. All good and seasonal.

[Snowman.]

Or it could all end in tears for coldies.

 Not sure why people are looking for cold at this time of the year. I tend to wait until the end of November before I get any sort of hopes, however this isn't a good position to be in for an average winter.

[Frosty.]

 Not sure why people are looking for cold at this time of the year.

It's not so much the cold itself, it's the building blocks which will lead to cold weather further down the line.

[BLAST FROM THE PAST]

Models are showing some interesting developments and we see the jetstream track further south as we go into FI.  I'm particularly interested in this part of the month as my mid autumn thoughts were that we'd get a bit more lively from the Atlantic and the track of the jet would move south.  I think a pretty unusual set up may occur towards months end with a deep LP attacking from well SW of us and a block in place from Norway to Iceland. 

The current model output looks not too out of kilter, even in FI.  The Atlantic inroad looks a bit more slack than I have anticipated [though its still FI] and could all change, and change a lot to even no inroads, but i think they're heading in the right direction For me at last we have interesting model output to look at again.

The set up we have had I've actually been a little disappointed as we didn't get the really 'indian summer' conditions here with too much cloud cover being persistently around.

 

BFTP  

Edited October 13, 2013 by BLAST FROM THE PAST

[johnholmes]

see below for the latest idea from ECMWF-GFS 500mb anomaly charts on how the upper air pattern may look in the 6-10 day time frame

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

This must carry some weight as it is very similar to the 6-10 day NOAA chart from last evening. The ECMWF-GFS was similar for the last couple of days. I did not save the NOAA 6-10 for the same days so I'm not sure if it too showed this. If it does then it does seem a fairly reliable idea, and not that usual a pattern type. The 8-14 version has so far not mirrored this idea but again this is not unusual for several days I've found with NOAA.

 

An interesting pattern anyway if it does turn out correctly.

[BLAST FROM THE PAST]

Is it me,or is the whole intense cold scenario all East side (North Pole Global Stats Current), Canada, Greenland etc (West Side) has nothing really. Apologises if i sound stupid,But i do not re-call seeing this output since i joined. If the Jet sinks further South, I'm guessing we could be looking at a real special Winter set up.

 

 

That isn't showing temp anomaly but heights.  The purple is where the Polar Vortex is?

 

BFTP

[Skullzrulerz]

Models are showing some interesting devbelopments and we see the jetstream track further south as we go into FI.  I'm particularly interested in this part of the month as my mid autumn thoughts were that we'd get a bit more lively from the Atlantic and the track of the jet would move south.  I think a pretty unusual set up may occur towards months end with a deep LP attacking from well SW of us and a block in place from Norway to Iceland. 

The current model output looks not too out of kilter, even in FI.  The Atlantic inroad looks a bit more slack than I have anticipated [though its still FI] and could all change, and change a lot to even no inroads, but i think they're heading in the right direction For me at last we have interesting model output to look at again.

The set up we have had I've actually been a little disappointed as we didn't get the really 'indian summer' conditions here with too much cloud cover being persistently around.

 

BFTP

No indian summer yay!

[SMU]

Morning All-

 

Things are certainly NOT the norm at the moment with the hemispheric picture.....

 

The fledgling polar vortex is wedged over to the East of Svalbard- leaving the the upstream westerlies weaker than usual - hence the continued +VE heights over Greenland & residual split flow towards western Greenland-

(last year the vortex got stuck over the Canadian Maritimes & pretty much stayed there)

 

 

Im sure some have noticed over the last few days the models correcting & correcting south- this is because ( as mentioned before ) they will have some sort of background assumption about the general trends of the jet- IE seasonal increase in eastward flow over the atlantic-

 

Take for example the ECM at 168 2 days ago-

 

http://www.meteociel.fr/modeles/ecmwf/archives/2013101100/ECM1-168.GIF?00  look at the jet to the North-

 

http://www.meteociel.fr/modeles/ecmwf/runs/2013101300/ECM1-120.GIF?13-12 Now look its further south-

 

Its easier to see in the 850's

168 -

http://www.meteociel.fr/modeles/ecmwf/archives/2013101100/ECM0-168.GIF?00  0c along Shetland...

http://www.meteociel.fr/modeles/ecmwf/runs/2013101300/ECM0-120.GIF?13-12 0c over England- -6 into Scotland

 

If you think North of 60 N is in a funny shape- look where the jet is @ 240 on the ECM-

 

http://www.meteociel.fr/modeles/ecmwf/runs/2013101300/ECH1-240.GIF?13-12

 

Somewhere along the line of spain heading East, where as usually its heading NW towards Iceland- that's a LONG LONG LONG way south.

 

In Summary, Its October, I doubt any of us really hope for bitter cold this time of year including me, however the winter coldies are coming out of hibernation & firing up for November.

Also the cold hasn't quite filtered to the whole of the UK- because the summer High over Europe hasn't quite receeded yet ( but it will do)

 

What I would say is whilst we cant guarantee any of this will sustain through into Winter it would seem that something is very usual this year- & if that continues things are exactly how we want it- with all the cold loaded to the ENE & pressure blocking over Greenland ( remember the sausage high)

 

If this continues expect early snowfalls over Scotland in North Easterly flows......

 

S

PS the NOAA daily & seasonal composites site is not working now due to the US government which is very frustrating.

Edited October 13, 2013 by Steve Murr

[Polar Maritime]

If only the ECMWF went out a few more frames ! look how far South the Jet is pulling them lows.

 

Edited October 13, 2013 by Polar Maritime

[Summer Sun]

Some colder uppers flirting with Scotland and northern England for a time before they get pushed away according to ECM, midlands south never sees the cooler uppers

 

 

Mild and wet looks a pretty good bet now for the south before this slowly pushes north during the week

Edited October 13, 2013 by Summer Sun

[BLAST FROM THE PAST]

Excellent posts again from Steve M and JH.  Yes the jet is well south and I'd go to say that its more than not the norm, its even more abnormal compared to the recent years' abnormalities.

Just of interest, ECM, GFS [further out] and I think GEM yesterday showed/show an assault building or happening by deep LP/s from well to our SW due to a well south jetsream. 

 

A question to JH, John you make a statement that its an interesting pattern and not that usual a pattern type.  Can you explain further as to why as that is an interesting comment from a very experienced meteorologist and not just a passing comment made by an amateur such as I.

 

 

BFTP

Some colder uppers flirting with Scotland and northern England for a time before they get pushed away according to ECM, midlands south never sees the cooler uppers

 

 

Mild and wet looks a pretty good bet now for the south before this slowly pushes north during the week

It ain't mild outside SS, its decidedly cool

 

BFTP

Edited October 13, 2013 by BLAST FROM THE PAST

[Summer Sun]

Latest from Gibby, a lot of average or a little above average temperatures can be expected less mild in the far North and NE but no real cold looks likely

 

The General Situation. All models show a Low pressure area close to Eastern England with areas of rain, some heavy spiralling South and West across England and Wales. One such belt is currently covering Eastern England and will extend SW through the day to many other Southern districts. The North and far West will see dry and occasionally brighter weather with some mist and fog by night. Through the coming few days the trend for the slow moving Low over the East to fill and dissolve away remains with less in the way of rain and wind for the SE with all areas drying out for a time if staying rather cloudy. The Atlantic will be dominated by Low pressure by midweek throwing troughs North and East across the UK with a strengthening SW wind. This will be followed by scattered showers by Thursday with some sunny intervals before another series of troughs and parent Low move steadily in from the West. It will never be cold through this week with all areas away from the very far North keeping mild Southerly breezes.

 

GFS then shows a sustained period when troughs remain straddled over the UK with reinforcements being fed up from the South and SW at times. This means it looks like Central areas especially could see some persistent and heavy rain while Southern areas too see some of this but with a few brighter spells in between. The far North may see less rain, more intermittently with a slightly cooler SE breeze here. Through the latter stages of the run start from early next week staying very unsettled and somewhat colder as cyclonic winds cover the UK bringing in colder uppers off higher latitudes of the North Atlantic while maintaining heavy rain and showers at times for all areas. With all the cloud and rain frost and fog on a widespread scale seem unlikely.

 

UKMO shows it's next weekend charts with a mild Southerly cyclonic flow in association with Low pressure covering the Atlantic. All areas would be subject to rain or showers at times in temperatures at average or above average levels everywhere.

 

GEM also has Low pressure in complete domination over the period from the end of this coming week until the end of it's run. While northern and NE parts may see a drier and colder interlude  for a time the emphasis remains on troughs stretched across Central areas with rain for many with a further surge of mild Atlantic South-westerlies next weekend bringing further spells of rain and showers NE to all with some persistent and heavy rain at times for almost anywhere in mild SW winds. It may become somewhat fresher late in the run as the Low pressure complex formerly over the East Atlantic and UK finally fills and moves away East.

 

NAVGEM also has the UK dominated by Low pressure to the West with mild SW winds over England and Wales and rather chillier Easterly winds over the far North. All areas would suffer spells of heavy rain at times in blustery winds with just brief drier spells in between.

 

ECM shows a cooler and brighter interlude towards the end of this working week as colder air flirts with the NE for a time. Through next weekend and the following week Low pressure over the Atlantic will displace this at the expense of Low pressure troughs moving up from the South and SW with further spells of rain and mild and fresh winds from the South or SW. At the end of the run the Atlantic is dominated by Low pressure with the UK looking down the barrel of a wet and breezy spells lasting well through the following week but we may have to keep an eye on High pressure to the NE bringing cooler air from the SE into NE areas at times.

 

The GFS Ensembles continue to support a very average spell of weather for this time of year with cloud, wind and rain all featuring in a large way through the period of the run. Temperatures will be close to average overall with no support for anything notably colder from the output this morning affecting the UK anytime soon.

 

The Jet Stream continues to be the culprit of the upcoming spell of Atlantic weather as it currently is crossing the Atlantic towards the South of the UK and France later this week. It then looks like maintaining this position give or take a couple of 100 miles over the following period.

 

In Summary this morning the pattern looks largely similar to that of yesterday with all areas seeing rain at times over the coming two weeks. With Low pressure anchored out in the Atlantic for much of the period and winds from a South or SW point in association with it a lot of average or a little above average temperatures can be expected at ground level though this may well be offset by the wind and rainier spells. Conditions in the far North and NE look somewhat less mild and less wet as High pressure and cool weather to the NE may encroach across these areas at times, holding rain bearing troughs to the South and SW of these areas back but even here no real cold conditions look likely.

 

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