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

[MR EXTREMES]

A quick look at how I think the temperatures will improve in the days ahead, not much change tomorrow as it will be rather cloudy across the board, 15-17c, saturday closer to 20c in the south/se and nearer 16-18c further north & west and on saturday it's a nw/se split with some rain and fresh sw'ly winds for the far northwest of the uk but away from there, it looks dry and bright with sunny spells and temps feeling pleasantly warm at around average values, by sunday it will be a little warmer at around 22c for the south/se and 17-19c further north/west, then next week it continues to warm up with sunny periods and light winds with temps into the low to mid 20's celsius, parts of the south will probably exceed 80F at times next week so it will be feeling like it's summer again although sunshine amounts will be variable and overnight mist and fog would need additional time to burn away.

 

I think approach with caution would be advised because realistic outlook shows a gradual cool down and more unsettled conditions as for exceeding 80f I think that's a tad ott more like mid 70s.

the models will now start to wonder around for awhile until ex alantic storms start to make there presents felt and the track of these storms will cause alsorts of model headaches but as gibby has suggested theres possibly a swift breakdown next week also a cool down autumn is here and winter round the corner so make the most of the warm 5 days or so ahead of us.

The GFS 06z operational run shows an anticyclonic spell and a big warm up by early next week with temps rocketing into the mid to high 70's F, I would not be surprised if some parts of the south & east reach 27-28c during next week, the uppers certainly look good enough, very impressive by late september standards and indeed, summer, so the 6z shows a very warm spell with increasing amounts of sunshine as time goes on and light winds but from a week tomorrow it turns generally unsettled but continues just on the warm side of average across the south of the uk, trending cooler across the north and more cyclonic across the uk, the unsettled weather is most persistent across the north & west later in FI with occasional high pressure in the southeast where the best of the weather would be, however, I think the unsettled FI is unlikely as i'm going with the much more settled/benign ecm 00z ens mean as guidance with the settled spell set to continue into october.

nw flow or west flow does not really suggest warm side for the south average more likely.

[Scorcher]

 theres possibly a swift breakdown next week also a cool down autumn is here and winter round the corner so make the most of the warm 5 days or so ahead of us.

 

 

Famous last words, I think all the warm fans thought the same about March this year and that the cold couldn't possibly hang on for much longer, yet it did. The weather doesn't pay attention to the calendar. The GFS 06Z shows above average conditions well into FI and any breakdown is well beyond the reliable time frame at the moment. 

 

In addition it looks to me like the mid to high 70s or 24-26C will be reached somewhere in the South on Monday and Tuesday, possibly both, and 22-23C could be widespread going by the GFS. The ECM looks even warmer for Monday. A lot will depend on sunshine amounts I imagine.

Edited September 19, 2013 by Scorcher

[Frosty.]

I think approach with caution would be advised because realistic outlook shows a gradual cool down and more unsettled conditions as for exceeding 80f I think that's a tad ott more like mid 70s.the models will now start to wonder around for awhile until ex alantic storms start to make there presents felt and the track of these storms will cause alsorts of model headaches but as gibby has suggested theres possibly a swift breakdown next week also a cool down autumn is here and winter round the corner so make the most of the warm 5 days or so ahead of us.nw flow or west flow does not really suggest warm side for the south average more likely.

I think the 850's look very summerlike across more southern areas for most of the 6Z op run, trending cooler in scotland eventually,however, it's all hypothetical since I think we are in for a more prolonged warm settled spell than this run shows.

[MR EXTREMES]

well heights got to go somewhere and as gibby explained its also possible to be on the cooler side of heights.

I think if we were to bank the gfs 6z based on one run then there would be no model discussion forum so there for its one run and the bigger two and the up and coming storm track might well cause a few headaches I wait until the weekend to see how prolonged and how warm its set to be.

 

and I would not be surprised to see the first signs of real autumn weather showing tonight on the 12z of coarse they will have each there own idear.

[Frosty.]

well heights got to go somewhere and as gibby explained its also possible to be on the cooler side of heights.

I think if we were to bank the gfs 6z based on one run then there would be no model discussion forum so there for its one run and the bigger two and the up and coming storm track might well cause a few headaches I wait until the weekend to see how prolonged and how warm its set to be.

 

and I would not be surprised to see the first signs of real autumn weather showing tonight on the 12z of coarse they will have each there own idear.

I'm going with the ECM 00z ensemble mean, staying anticyclonic and warm or very warm from the weekend onwards, I think the 6z op run is wrong about the outlook for that reason, it will take a lot more than 1 op run showing unsettled for me to take more notice of it.

[No Balls Like Snow Balls]

.... that depends which set of data you chose to believe.

 

the 06z gfs brings the warm upper (10c isotherm) over the country on saturday, and for at least half the country thats where it stays until next friday... 7 day of potential warmth. that run also suggests we are under at least the 5c upper for most of the country for most of the run.

 

ok thats possibly the run that suggests the warmest scenario.... and we are likely to get something less then what the 06z gfs would have us believe. but so what? the outlook is warm/above/near average... thatll do for me!

 

Both the latest ECM and GFS ensembles show a tumbling of daytime temps from Tues/Weds, perhaps they will both be wrong?, who knows?, but there is the data, and this particular data has never once shown a sustained period of warm / very warm temps.

 

 

Whilst the 850's may look summery, this isn't July or August this is late September, and the actual reality on the ground looks like it's gonna be something different to what you would expect in the height of summer according to these ensembles.

Edited September 19, 2013 by No balls like Snow Balls

[Stormyking]

Hey Guys, not sure if my eyes are correct or not, but I have also notice the GFS shows some signs of possible late september plume, its close anyway.

 

 

Also looks as though GFS and ECM hinting at a breakdown as we go into FI, which should be interesting

[Man With Beard]

564dam line over the whole of the UK by Sunday. Not often you see that in late September.

Won't be cold anywhere. I'd have thought anywhere could reach 20C with that chart and maybe 25C in prolonged sunshine

[Frosty.]

The GEFS 06z mean has more than a passing resemblance to the 6z op run but just doesn't become as cool or as unsettled as the op does across the north although it's clear to see that proper autumn weather (very cool & unsettled) gets uncomfortably close to the north of the uk as the PFJ extends further south as time goes on with northern europe cooling down significantly, however, for the south of the uk it looks like a warm anticyclonic spell is assured with temps rising daily from saturday and throughout the first half of next week, increasingly very warm and sunny weather is expected for most of next week across the southern half of the uk but northern britain doesn't look as good and trends very unsettled between T+192-240 hours and much cooler. However, we all know what some on here  think of the 6z and the gfs in general and the alternative view would be to support the nicer ecm 00z ens mean instead, which I am for now.

[Captain Shortwave]

564dam line over the whole of the UK by Sunday. Not often you see that in late September.

Won't be cold anywhere. I'd have thought anywhere could reach 20C with that chart and maybe 25C in prolonged sunshine

Precisely, I would be surprised if there was a lot of cloud cover, especially the further south and east you go, the flow is off the continent even though it's from the south west for most of the UK. The ECM is still undercooking temperatures for the weekend and the beginning of next week. The GFS yet again by the timeframes involved looks about right.

Edited September 19, 2013 by Captain shortwave

[mushymanrob]

Both the latest ECM and GFS ensembles show a tumbling of daytime temps from Tues/Weds, perhaps they will both be wrong?, who knows?, but there is the data, and this particular data has never once shown a sustained period of warm / very warm temps.

 

ensemble-tt6-london.gif

 

Whilst the 850's may look summery, this isn't July or August this is late September, and the actual reality on the ground looks like it's gonna be something different to what you would expect in the height of summer according to these ensembles.

 

im not saying they will be wrong, its all predictive and is only as acurate as the ever changing current data predicts. the ensembles are no more or no less accurate then the ops... my point being that whilst you point out that some data suggests the warmth will be short lived, other data suggests it wont, but either way, its not going to be cool/cold! yep, we know its not july, i for one have already mentioned temps in the 17c - 23c range, and this looks like becoming reality. and i for one am happy enough with that!

[johnholmes]

only as acurate as the ever changing current data predicts. 

 

It is not the the data; that changes only by relatively small amounts when taken in the context of global modelling, but the subsequent run of a model can change significantly on both global and local scales.

[Frosty.]

The GEFS 06z control run produces some very wintry synoptics but 2 months early, yes the charts in FI are similar to what we had at times last winter and especially in nov/dec 2010 but in late september/early october it would just be very cool, wet and windy with temps around 10-14c although it would become cold enough for wet snow across the scottish mountains.  This run shows what the Gefs 06z mean and especially the 6z operational run threatened to produce but never followed through with...in the meantime, a spell of summery weather is on the way with temps widely into the low 20's celsius from sunday and mid to upper 20's c for the south & east for much of next week. As I said, charts like these are a complete waste of time even if they did verify, wet and cool...come back in late november.

Edited September 19, 2013 by Frosty.

[Captain Shortwave]

Well if we had model uncertainty before with one cut off low, well the GFS ups the ante here, 2 cut off lows

Just going to assume every model is probably going to have a different solution at day 5/6 already.

GFS T144

 

Previous run

Oh dear, the GFS is drunk, blindfolded and in possession of a lot of darts.

Well GFS saying Wednesday and Thursday would be warm as well. Northern France would be experiencing a full blown heatwave, so close but yet so far.

UKMO is an absolute stunner, would be fine and very warm to T144 and beyond.

Edited September 19, 2013 by Captain shortwave

[AWD]

Hey dude, where be my high?

To balance that out, up until Wednesday looks dry and very warm in the sunshine for the time of year. Whether it will last all of next week or not still remains uncertain for me however.

At least I can dust the BBQ of this weekend though, sunshine pending!

[Summer Sun]

UKMO holding firm

 

Edited September 19, 2013 by Summer Sun

[AWD]

Now if this isn't uncertainty, I don't know what is;

Weekends looking decent, as is the start of next week. Midweek onwards, who knows!!

[ANYWEATHER]

Well the gfs keeps any high pressure short-lived for next week with low pressure taking control from Wednesday! Different story then from a few days ago  

[AWD]

Well the gfs keeps any high pressure short-lived for next week with low pressure taking control from Wednesday! Different story then from a few days ago

To balance that out though, the UKMO doesn't, keeping pressure high instead. One would normally favour the UKMO over the GFS Op too, but of course, that could be influenced by the ECM later and ensemble output too.

Uncertain times after a decent Sat - Tues period.

Edited September 19, 2013 by SeasonalWeatherWatcher

[Milhouse]

Hey dude, where be my high?

image.jpgimage.jpg

To balance that out, up until Wednesday looks dry and very warm in the sunshine for the time of year. Whether it will last all of next week or not still remains uncertain for me however.

At least I can dust the BBQ of this weekend though, sunshine pending!

 

Should be decent BBQ weather, and not too chilly in the evening either with temperatures set to hold up well overnight.

 

[Captain Shortwave]

Well the gfs keeps any high pressure short-lived for next week with low pressure taking control from Wednesday! Different story then from a few days ago  

Also worth noting that temperatures will be at 20C or above until next Saturday in the Midlands south. There would be rain which would be coming up from the south later next week (perhaps thundery?). The GFS is pretty good, well for the South, cooler and a little more mixed further north after Tuesday.

UKMO on the other looks pretty high pressure dominated.

Alas we have not 1 but 2 potential cut off lows forming which pretty much mean we have 3 upper ridges interacting with each other at the same time. Yeah a lot of potential and different solutions there

One thing to be positive about is how sluggish the pattern looks over our side of the pole, whilst the Pacific and Siberian areas are controlled by the developing Polar Vortex.

Oh by the way, Northern France might be a good bet for an early Autumn break next week. If you like multiple days of 30C heat 

Edited September 19, 2013 by Captain shortwave

[Cheshire Freeze]

Text book Greenland blocking. Shame it's still early autumn and not the depths of winter...

 

 

 

I'd be in the process of being buried under a foot of snow with the wind direction on that second chart

[Frosty.]

The UKMO 12z is a STUNNER..High pressure is booking a long holiday over the uk, even by T+144 hours it looks like it could stay anticyclonic for another 10 days or more, hope the ukmo is right, according to the pendulum it will be  

[AWD]

12z GEM, although with some differences still, broadly supports the UKMO chart;

Along with latest Met Office update, 12z GFS Op looking a little isolated so far!

[Frosty.]

Yep it looks like a settled and warm outlook is still on track, a rogue 6z control run showing unsettled is nothing to be concerned about, looking forward to summer coming back now, have to say the models picked this trend weeks and weeks ago, ran with it dropped it, ran with it, dropped it and now it's reality, although at no stage has the 500 mb anomaly charts been fully behind it, indeed for most of the time it's been against it, until very recently. This is going to be like July weather next week.