Model Output Discussion 06Z, 13 Sep. 2013 ---->

[cheese]

And yes, just because the London area hasn't been enjoying sunshine and warm temperatures doesn't mean that the rest of us haven't- it's been fantastic here this afternoon with mostly clear sky and temperatures of 21C.

Same here, but only today. The past few days have been disappointingly cloudy and cool. Looks OK tomorrow and possibly Tuesday before going downhill again. So really nothing unusual for the time of year.

Edited September 22, 2013 by cheese

[syed2878]

Here's the latest from gibby.

ISSUED AT 20:00 ON SUNDAY SEPTEMBER 22ND 2013

 

Good evening. Here is the report on the 12 midday outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Sunday September 22nd 2013.

　

All models continue to show a large High pressure area close to SE Britain with a warm and moisture laden airflow over the UK. The resultant warmth will be accompanied by low cloud, mist or fog over the next few days but some warm and sunny weather increasingly likely at times. Through midweek a Low pressure trough intensifies near Northern Scotland and pushes South somewhat with rain affecting Northern areas then as well as a marked drop in temperature. As pressure falls elsewhere too Low pressure to the SW could throw up some showery rain at times but the South should at least stay warm until the end of the working week. Over the weekend to come things take a more notable turn downhill as Low pressure makes a more meaningful impact on a larger part of the UK.

　

GFS shows Low pressure extending North across Southern Britain at least with rain at times down here while the North holds on to drier weather following the late week rain. Then through next week the mild and unsettled air over the South makes it's way North to all areas with a brisk and cooler westerly wind with showers following before a shift of wind towards the NW or North at the end of the run turns things very much colder then but drier as pressure builds to the West.

　

UKMO tonight shows next weekend with Low pressure North and South of the UK with rain at the top and tail of the UK while a large swathe of Central Britain while at risk of a few showers would still see plenty of dry if rather cloudy weather and mild weather.

　

GEM shows Low pressure gradually strengthening down to the SW later this week with a deep depression spinning North up the Western side of the UK through the weekend and start of next week with spells of heavy rain followed by thundery showers, heaviest in the South and West where gales would also be likely. Overall temperatures would hold well up to average despite the wind and rain.

　

NAVGEM also shows Low pressure deepening and spinning around NW Britain next weekend and at the start of the following week. There would be gales in the West with some heavy rain for all at times. It would probably feel cool but temperatures would not be far from the seasonal normal.

　

ECM tonight shows Low pressure becoming dominant over and then to the NW of the British Isles from next weekend. High pressure to the NE will restrict the Eastward progression of these Lows with the majority holding to the NW and West and ensuring mild SW winds hold sway over the UK. So despite frequent bouts of wind and rain temperatures would stay respectable overall.

　

The GFS Ensembles show a steady cool off through the week with average levels of temperature sustained thereafter. After a dry few days the cooler air will usher in rain from the North innitially before more generally from the SW next weekend and beyond with some quite heavy rain possible at times thereafter.

　

The Jet Stream shows the flow weakening to nothing North of Scotland over the next few days. The Low to the SW engulfs a new arm of the flow exiting the States later in the week and encourages the Low to deepen as it moves steadily Northeast next weekend and beyond.

　

In Summary tonight we are seeing a delay in bringing the unsettled weather across all of the UK in meaningful fashion. It now looks that the far North will see rain from Tuesday with some other northern areas too at risk midweek. The far South too may see a few thundery showers later in the week as it stays warm here until next weekend. It's then that the Low pressure complex to the SW spreads it's wings NE to affect the UK with rain and showers at times with potential strong winds at times. It does look less likely that any cold weather will affect our shores anytime soon as away from the far North for a time this week winds will flow from a warm Southerly source maintaining temperatures at average levels despite wind and rain.

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

[Tony27]

ok i know this is imby but the bbc 5 dayer looks nothing special it shows my area to be cloudy for most of the week with some drizzle on wed and thurs with temps on them days at 18c 19c, only tomorrow looks to be a nice day with temps at 21c, the models with all its fancy red and yellow colours are probably fooling us again, so nothing special really just a bit of normal warmth in september which happens most years, but better than last weeks chilly weather

Edited September 22, 2013 by Tony27

[Frosty.]

The Ecm 12z operational is certainly a warm run, initially very warm for the time of year, then a slight cooling before another surge of continental warmth and increasing humidity pumps north across the uk later in the week, it also starts fine with sunny spells but by friday it looks like a breakdown is afoot as a trough pushes in from the southwest/south with an increasing risk of showers which would become heavy with hail and thunder but with sunnier gaps between. The main story of tonight's Ecm is a large trough becoming anchored to the southwest of the uk which enables warm southerly/se'ly winds to persist with the most persistent rain for the southwest & west of the uk eventually, more of a warm and humid mix of sunshine and heavy showers for the rest of the uk, no sign of anything cold on this run but plenty of warmth, thats for sure.

[Man With Beard]

My gosh, that's some unusual cold pushing into Scandi/N.Europe at day 10 on ecm. Of course that's a long way off, but I don't ever remember seeing this cold set-up so early in the season...

 

This is really fascinating. Two extremely different air-masses on course for the UK. The cold source from the NE looks genuinely wintery and a classic Scandi High as well which, if correctly aligned, could send the whole lot our way. Surely it couldn't turn that cold so early in the season? While summer-like warmth, similar to today (S Coast excepted!!), still on the verges. Wow. Would be great if a chart like this verifies, it has the potential to be a US-style weather change where temps can drop 15-20C in 2 or 3 days. Shame it's unlikely to be exactly like this!

 

Tony - BBC consistently forecasted 20/21C for today, yet a huge number of places reached 23C-24C. My reading of the models hasn't changed from posts I've made in recent days, I believe 25C+ potential remains over the UK on Monday, Tuesday and Wednesday, the location of the warmest places will depend on where the cloud breaks though 20C under total cloud cover is still impressive for this time of year.

Edited September 22, 2013 by rjbw

[summer blizzard]

Despite the warm outlook to the models tonight i suspect that many will be disappointed with the reality. With lower pressures (sub 1020mb) and lapse rates falling as they do this time of year this points to (from Tuesday) a higher likely-hood of cloudy warm sectors.

 

GFS12z operational somewhat confirms that...

 

[Jason T]

 

This is really fascinating. Two extremely different air-masses on course for the UK. The cold source from the NE looks genuinely wintery and a classic Scandi High as well which, if correctly aligned, could send the whole lot our way. Surely it couldn't turn that cold so early in the season? While summer-like warmth, similar to today (S Coast excepted!!), still on the verges. Wow. Would be great if a chart like this verifies, it has the potential to be a US-style weather change where temps can drop 15-20C in 2 or 3 days. Shame it's unlikely to be exactly like this!

 

Tony - BBC consistently forecasted 20/21C for today, yet a huge number of places reached 23C-24C. My reading of the models hasn't changed from posts I've made in recent days, I believe 25C+ potential remains over the UK on Monday, Tuesday and Wednesday, the location of the warmest places will depend on where the cloud breaks though 20C under total cloud cover is still impressive for this time of year.

 

 

That's a stonking ark of cold pooling over the Uk at Day 10, That has actually sent shivers down my spine. I do wonder if what has been progged for this Winter is actually beginning to evolve.

[SMU]

If you got a perfectly aligned flow out of the North east in -2c air at this time of year I guess you could see maxes of around 11-12c in the SE- maybe 7-10 in the North-

 

Its not cold enough yet for those proper wintry thoughts.. but it looks nice on the meteociel charts!!S 

[Gaz1985]

I wouldn't get too excited over a bit of cold over Scandinavia and NE Europe at this time of year. I think some people are getting carried away.

[Gaz1985]

Even up to Wednesday If the sun breaks through it would still feel pleasant across England and Wales 

 

[Man With Beard]

If you got a perfectly aligned flow out of the North east in -2c air at this time of year I guess you could see maxes of around 11-12c in the SE- maybe 7-10 in the North-Its not cold enough yet for those proper wintry thoughts.. but it looks nice on the meteociel charts!!S

Maybe not snowy but good frosts though - all hypothetical of course

[Frosty.]

Yes it's a warm or very warm week ahead for england and wales, it's still about 4 weeks until I become really interested about cold prospects.

Give the sea surface temps a chance to drop a little and the sun to lower and weaken..patience.

Edited September 22, 2013 by Frosty.

[damianslaw]

A benign outlook - very slack pressure pattern, not wholly unusual for late September, but quite unusual to see such a weak jet... southerly airstream is the end result.

 

My attention is on the projected rise of heights over scandinavia - this is quite unusual for late September, a feature more likely to surface later in October as we see proper cold pooling begin to establish itself over siberia and nudge its way into NW Russia.

 

Once again we are seeing a spell of warm settled southerly weather in autumn - we have seen so many such spells in recent autumns since 2005 - but conversely the colder winters... mmmm....

 

This is the time of year when we can expect the polar vortex to begin to ramp into action, but its influence over the next few days will be zero - much more like we would see in April and May.

The year as a whole has seen a rather weak jet, with very few deep low pressure systems making their presence felt, after a shortlved unsettled spell last week, once again high pressure wants to rule the roost. Its been a theme of our weather in the main since the start of 2010 barring the period April-Dec 2012 - only because the blocking was further to the east which in turn meant a love in with the atlantic trough.

 

From a personal perspective, roll on October... often far more interesting than September which in my book is our least interesting month weatherwise - it always leaves me frustrated...

[Iceni]

Strange, the satellite shows all of Cornwall and parts of Devon in the clear since mid afternoon.

BTW again an impressive high to our north east. Keeping us warm and when there are no fronts around pretty sunny, whilst plunging Russia and Eastern Europe into an early winter blast.

 

Could be one of those haar things. I remember setting off in blazing sunshine for a day on the beach - everything sunny until we got to within a mile from the coast. Then sea mist. It was miserable.

[mushymanrob]

cant add much to what most posters have delivered overnight, early coldies are trying to downplay what is a pretty good outlook, hold on guys, your time will come! but for now its looking like a reasonably warm week ahead, not as warm as the today/tomorrow, but never chilly. cloud is an issue.... as is... fog (thus proving earlier thoughts by some correct).

 

i cant see anything in any model that would suggest anything particually cold, or hot, is likely for us...just pretty normal autumn weather albeit on the mild side of average.

[Captain Shortwave]

No model appears to have changed much since yesterdays 12Z runs, again disagreements at just T96, ECM is interesting though at T144

Heights building to the north of Scotland

[Frosty.]

cant add much to what most posters have delivered overnight, early coldies are trying to downplay what is a pretty good outlook, hold on guys, your time will come! but for now its looking like a reasonably warm week ahead, not as warm as the today/tomorrow, but never chilly. cloud is an issue.... as is... fog (thus proving earlier thoughts by some correct).

 

i cant see anything in any model that would suggest anything particually cold, or hot, is likely for us...just pretty normal autumn weather albeit on the mild side of average.

I agree with you 100% Rob

[Polar Maritime]

Yes, it's that time of year again where the hot/cold battle commences, which is why Sep/Oct is a nightmare to forecast. 

 

But as Mushy has stated nothing in the chart's are showing either, just normal standard Autumn weather for the next few day's. But with high pressure continuing to push North keeping the Polar Vortex very unstable,  Some very unsettled weather could soon be on our shores.

 

Edited September 23, 2013 by Polar Maritime

[Frosty.]

This snapshot at T+144 hours shows a confused picture but the overall consensus is it looks less settled than the first half of this week will be, the ukmo 00z looks most benign but with lower pressure and a risk of showers but there are some windier more unsettled options in there. I would say enjoy the warm and mainly fine spell that we start with because it looks like it will be turning more unsettled as time goes on with temperatures returning to average levels eventually.

[Paul White.]

Hi everyone does anyone know where I can find a chart viewer like gfs or ECM for Mexico riviera Maya region I'm going on honeymoon on October 19th a little way off but I want to be prepared thanks in advance for any help

Paul

[johnholmes]

well, at last the anomaly charts are starting to look as if they are all on the same planet-not totally convincing in their similarity or continuity just yet but getting there. The links to both are shown below, ECMWF-GFS and then NOAA.

The overall impression and that from NAEFS is that some kind of trough will be the major player not an upper ridge although that moving in at some point is a possibility. No sign of any cold plunge from a meridional type pattern developing either, nor major heat. Pretty much average autumn weather but no major storms would occur if the latest anomaly outputs are correct.

 

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

 

 

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

 

NAEFS below

http://www.meteociel.fr/modeles/naefs_cartes.php?mode=0&code=0&ech=192&map=&runpara=

Edited September 23, 2013 by johnholmes

[Summer Sun]

Latest from Gibby

 

Hi everyone. Here is this morning's walk through the midnight outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Monday September 23rd 2013.

 

All models show a warm and moist layer of air over the UK currently with either extensive low cloud and mist or fog overnight with some pleasant, warm and sunny weather for some areas through the daytimes. This pattern remains in place for several days as rain develops across the far North by midweek as a trough edges down from the North. All models show a slow decline in temperatures and conditions later in the week although they differ on timing and specifics as the general trend is still for cloud and rain to move slowly North and East across the UK towards next weekend with the warm conditions slowly easing back especially over the North.

 

GFS shows the rain moving NE across the UK next weekend with some heavy rain in places before drier conditions follow the rain through the early part of the second week in association with a ridge crossing East over Britain. It would be much cooler at this point though. Then a re-run of rain crossing from the SW keeps the changeable theme going late in the run with a switch to Northerly winds at the close of the run with rain or showers in cool conditions as High pressure builds North through the Atlantic.

 

UKMO shows Low pressure closing in on the British Isles next weekend from the SW, West and North with the threat of rain becoming widespread very likely as we move into Sunday and the days that follow.

 

GEM shows a strengthening South or SW flow as a deep Autumn Low pressure area moves NNE up the Western side of the British Isles with strong winds and bands of heavy rain affecting all areas at times. Although the weather will be mild innitially as winds swing Westerly through next week more showery and cooler conditions look likely for all.

 

NAVGEM shows Low pressure spilling close to the UK from the SW next weekend with troughs moving NE across Britain with rain followed by showers with plenty more Atlantic frontal activity bringing further rainfall in across the UK next week.

 

ECM shows an unsettled end to next weekend with rain at times as fronts and Low pressure makes it's way into the UK from the SW. Through next week a mild and unstable South to SW airflow maintains cloud and rain at times for most of

the UK, especially over the West.

 

The GFS Ensembles show a slide into cooler conditions as we move through the next 10 days or so though it takes more than a week to bring levels down closer to the seasonal average for most. Rainfall becomes a much more common feature too starting in the North on the 25th and spreading to the South too by the 27th or 28th.

 

The Jet Stream continues to show the flow weakening to the north of the UK with a relocating arm to the SW of Britain developing by the end of the week.

 

In Summary conditions are set to deteriorate over the coming week to 10 days. The weather is in no hurry to do so with most parts seeing a reasonable week to come with warmish conditions hanging on in the South until the weekend with just scattered outbreaks of rain possible after midweek, especially in the North. All models then show a more coherent area of Low pressure meandering north and East across the UK at the weekend  and probably others to follow with the period thereafter looking changeable with wind and rain at times with temperatures still well up to average for this time of year. The heaviest rainfall looks likely for the West with Northern European High pressure blocking any transit East of most Low pressure.

 

http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htm

[No Balls Like Snow Balls]

Looks like unsettled conditions will affect all the UK this weekend not just the Midlands North like later this week.

 

 

 

Still warm though.

 

ECM too

 

 

 

 

 

 

 

 

Edited September 23, 2013 by No Balls Like Snow Balls

[Frosty.]

This morning's Ecm 00z ensemble mean shows a benign spell for most of this week with a very slack pressure pattern, rather stagnant for a time with most of the weather action well away over northeastern europe and well to the southwest of the uk, for the uk, this week starts anticyclonic and warm with some sunshine breaking through at times and temperatures between 20-23c, 20c where it stays cloudier, further north across scotland it looks relatively cooler with some rain at times but as a ridge extends south from an anticyclone to the east of Greenland, the far north should turn brighter as a weak band of rain slowly pushes south through scotland tomorrow. During this week, the high pressure will slowly leak away and we need to keep an eye on a large depression slowly pushing northeastwards towards the uk by friday because it looks like a more unsettled weather pattern is on the way from friday onwards with an increasing risk of showers, some heavy, prolonged and thundery but with sunny periods between, at least with winds sourced from a generally southerly point, the temperatures will continue to be very respectable for late september, feeling rather warm and muggy for a while actually but by next week the mean shows the uk being strongly influenced by a slow moving depression to the west of the BI and temperatures drifting down to average as the airflow becomes more oceanic, slowly mixing out the warmer continental uppers and eventually bringing a more typical british autumn weather pattern, windier, relatively cooler and more unsettled with rain interspersed by sunshine and showers and the brightest, warmest spells across the southeast of the uk from time to time, the most unsettled windiest weather for the north & west.

Edited September 23, 2013 by Frosty.

[Frosty.]

Watch out tonight folks, there is a lot of fog likely to develop where skies are clearest with some very dense patches, especially across the south and southeast which will make it a tricky rush hour tomorrow morning.