Model Output Discussion - 17th Oct Onwards

[Paul]

Please carry on the model discussion here. Don't forget we have a zero tolerance policy when it comes to bickering, point scoring, disruptive posts and the like so please ensure you don't fall foul of that.

 

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[shedhead]

No significant changes across the model suite this morning, with LP anchored to our west and feeding mild or very mild air up across the UK for the next week at least. Right at the end of the run ECM hints at rising pressure in the south, but GFS is having none of it, with mild air having flooded, deep, deep into Arctic Russia by that time. Any Eurasian snow cover looks very vulnerable IF the GFS verifies.

 

 

 

 

 

 

 

Edited October 17, 2013 by shedhead

[Summer Sun]

Latest from Gibby

 

All models show a similar pattern over the coming 4-5 days with the general message being an unsettled one revolving around Low pressure to the West of Britain and High pressure over Europe. There are small scale changes this morning in the shortest term in that the wet weather tomorrow has been pushed further West and will leave the East and SE of the UK in a drier and potentially foggy period tonight as a ridge pushes across these areas later today and a drier day tomorrow than originally thought. Beyond tomorrow the trend is as before with various troughs and Low pressure areas pushing up from the SW delivering periods of rain, heavy at times interspersed with showers and sunny intervals. It will stay mild overall though Northern Scotland and the Northern Isles could stay rather colder for a few more days yet.

 

GFS then shows next week as an unsettled one with wind featuring rather more than currently with gales in places as successive Lows and troughs swing NE close by to the UK. The temperatures would become academic as the wind will temper the mildness of the overall values through most days. There could be some copious rainfall totals at times especially near windward slopes facing SW with just shorter drier and fresher periods in between the rain. Things are shown to dry out towards the SE late in the run but no less mild with a long fetch SW strong flow bringing warm and moist air from the tropics and delivering rain and drizzle to many Northern and Western areas.

 

UKMO closes it's run today with a deep Low to the West of Ireland with SW winds across much of Britain with troughs embedded in the flow. These would bring spells of rain North and East across the UK in continuing mild and windy conditions for all.

 

GEM also keeps the changeable and unsettled theme going throughout next week as Low after Low pushes North across Western Britain pulling their troughs NE across all areas with strong winds up to gale force at times with spells of heavy rain and shorter more showery periods in between. There are some signs that the North could become less mild very late in the run as Low pressure anchors more towards the SW.

 

NAVGEM keeps a very turbulent spell of weather over the UK next week as a conveyor belt of Low pressure crosses the Atlantic and crashes into the UK with active fronts and strong winds delivering showers and longer periods of rain to all in temperatures near to or above normal throughout.

 

ECM is a little calmer today despite continuing to show changeable and mild weather for much of next week it offers higher pressure feeding North towards Southern Britain later next week fending Low pressures further to the NW and allowing Southern Britain to become dry and very mild with a weak SW flow. Such improvements look less likely for the North and West as weaker troughs move North and NE afflicting these areas with grey but mild conditions with rain and drizzle at times. As a precursor to this Northern areas may become somewhat cooler for a time.

 

The GFS Ensembles this morning show close agreement on a sustained mild and Atlantic based weather pattern with highly changeable conditions alternating between spells of rain and brighter days with showers. With winds always from a SW direction things would remain mild overall with little likelihood of frost and fog due to the mildness, cloud cover expected and the strength and source of the wind.

 

The Jet Stream driving these synoptics shows a new position much further South than recently over or to the South of Britain through the coming week. Changes are slow thereafter though there looks like at least the possibility of it moving further North over the Atlantic in 10 days or so.

 

In Summary today the mild theme continues with rain at times likely for all. As always in these changeable Atlantic based patterns the heaviest rain will be in the North and West while the South and East might well be favoured for some shorter drier interludes with rather more than that if ECM's output is realised for later next week. All charts from all models point towards above average or average temperatures at worst with little widespread frost or fog problems away from tonight. The pattern looks set for some considerable time with any trend arising from this morning's output showing a shift North of the Jet late next week which though currently speculative would only serve to maintain a milder still and drier South or SW flow over Britain pumped up by higher pressure over Europe.

 

http://www.norton-ra...is(2859336).htm

[Summer Sun]

We need to away the ensemble run from ECM to see what support it has but towards the end of its run ECM starts to become calmer than of late

 

[draztik]

ECM offering hope to those that want drier, calmer weather.. with a pressure rise at the end of its run. This is reflected in forecasted rainfall over this period, with higher levels for the NW while the SE & East Anglia see less. All in all, big changes by day 10 from the Euro..

ECM 12z from last night

ECM 0z

[draztik]

Edit, The ECM ens give little support for any significant pressure rise.

Edited October 17, 2013 by draztik

[shedhead]

Edit, The ECM ens give little support for any significant pressure rise.

Indeed and probably no surprises really at this stage.  Uncle Barty may already be packing his bags for a late October visit and once the old codger settles in he's a bugger to shift....

Edited October 17, 2013 by shedhead

[Paul_1978]

I noticed Gibby's summaries are copied and pasted here. Where does he actually post them?

[draztik]

I noticed Gibby's summaries are copied and pasted here. Where does he actually post them?

http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htmpretty sure Gavin always gives the link.

[Summer Sun]

I noticed Gibby's summaries are copied and pasted here. Where does he actually post them?

 

The link at the bottom of the post

[Frosty.]

The Ecm 00z ensemble mean shows a mild, windy and very unsettled outlook with a large depression to the west/sw of the uk becoming the dominant feature, winds generally between s'ly & sw'ly from the azores so temperatures very much on the mild side, occasionally rather warm air pumping up from southern europe with the warmest spells across southern, eastern and southeast england, however, in my opinion, there are indications that a colder spell would be possibly brewing beyond T+240 hours as the lows look like eventually pushing further east and enabling a colder nw'ly flow towards the end of the month, even if that doesn't happen, the mean shows a cooling trend by later next week with more of a westerly flow, so I think there are hints of a change eventually.

[Methuselah]

Those are just the charts I like to see, in October, Frosty.

[Newberryone]

ECM offering hope to those that want drier, calmer weather.. with a pressure rise at the end of its run. This is reflected in forecasted rainfall over this period, with higher levels for the NW while the SE & East Anglia see less. All in all, big changes by day 10 from the Euro..

ECM 12z from last night

ECM 0z

Agree, tentative signs of a gradual improvement/settling down in weather conditions by then but surely one has to be mindful of the fact this is only based on one run and as already highlighted this outcome as of now has less support from the ECM ens.

Like Karl, I too will be pulling my hair out if Uncle Barty becomes the dominant player at this stage.  

[shedhead]

Those are just the charts I like to see, in October, Frosty.

I agree Pete...we are going to have a protracted mild/very mild and wet spell at some stage across the next 5 or 6 months, so I'm sure most would prefer to have it in Oct/Nov, rather than during Dec/Jan.  This of course is no guarantee that winter won't be domimated by this kind of pattern, much as Roger Smith has suggested in his Seasonal Forecast post, but at least any damage at this time of year is very limited.

[Frosty.]

The Gfs 06z op run is quite a wild ride, lots of wet & windy spells as atlantic depressions sweep in on a generally sw/ne aligned jet, and just occasionally through FI there are spluttering attempts to drag colder air down from the northwest but for the next week or so it looks mild, becoming very mild / rather warm for a time early next week and then back to mild but on this run there are some settled and cooler interludes and cooler, showery days but the high res is dominated by mild / very mild air. It was hard to find any significant settled weather until near the end of the run as high pressure eventually builds in and beyond this, the high would probably become dominant with the jet being forced even further north in the process, at least temperatures return to closer to the late october / early november average as time goes on through the low res.

[Bobby]

Agree, tentative signs of a gradual improvement/settling down in weather conditions by then but surely one has to be mindful of the fact this is only based on one run and as already highlighted this outcome as of now has less support from the ECM ens.

Like Karl, I too will be pulling my hair out if Uncle Barty becomes the dominant player at this stage.  

 

It only looks like a temporary ridge to me, that deep low winding up to our West is surely heading our way if the model went to the next frame bring further unsettled weather especially to the N and W. As usual the SE with the best chance of drier weather.

[shedhead]

The eastwart extent of the milder air (like it or not) looks fairly impressive on the NH t+180hr, even for late October. This time next week it's shown to have comfortably pushed past 60E and looks ready to assult the Urals....look out Vladivostok

 

[Frosty.]

For those interested in the upcoming weekend weather, the Gfs 06z op run looks close to the mark and shows a band of heavy rain pushing northwards across scotland and slowing down, even stalling as it hits the cold block to the northeast, this means there is a risk of local flooding across the northern half of scotland with 24 hours of persistent and sometimes heavy rain, especially for the far north where it could rain non stop for 36-48 hours before the fronts eventually clear shetland, however, for most of the uk, it looks like a warm weekend for the time of year with sunny spells and scattered heavy showers with thunder and hail with warm ssw'ly winds, occasionally the showers banding together to give longer spells of rain but in the sunshine it will feel more like september than late october. Staying mild next week with low pressure to the southwest of the uk being the driver with further wet and windy spells and only short, brighter and drier gaps between, the best of these towards the southeast.

[Frosty.]

 

 

180? Surely that would be FI if it was showing cold?

I think relatively colder weather will arrive beyond T+240 hours, just my instinct based mainly on the Ecm 00z ens mean, I think the overall pattern will get a shove further east allowing colder polar maritime air to replace the persistent mild Tm airmass, of course, I could be completely wrong and the mild mush could go on into november.

[Captain Shortwave]

Personally I think the jet will probably move further north with time to allow the Azores high to build to the south or maybe over the UK in due time as the polar vortex migrates to Greenland and then Canada. Probably with a more settled spell during the 2nd week of November with the days becoming chilly where fog persists.

[Frosty.]

Personally I think the jet will probably move further north with time to allow the Azores high to build to the south or maybe over the UK in due time as the polar vortex migrates to Greenland and then Canada. Probably with a more settled spell during the 2nd week of November with the days becoming chilly where fog persists.

Yeah, that happened on the 6z chart I posted earlier with the jet forced northwards.

[karlos1983]

Yeah, that happened on the 6z chart I posted earlier with the jet forced northwards.

let's hope not...

[Frosty.]

let's hope not...

I wouldn't mind because there would be some air frosts and crisp mornings..but also fog patches.

[smithyweather]

Has it not already done that? I mean it is 16c and sunny. 

[Paul]

Helloooo!! This is the model thread, not general chat about anything else thread, thanks