Alternate Model Discussion - into 2022

[knocker]

14 minutes ago, johnholmes said:

Thanks for that, not seen it, well not tried to use it, so will keep an eye open for how it does. Have you formed any opinion on it?

 

Not really John as I haven't been using it for very long.

[phil nw.]

The gefs pressure graph for C.England

underlines the large spread of possibilities wrt the movement and placement of the high after day 5.

 

[Methuselah]

Hi guys, I've defected from t'other thread; this one looks a 'tad' more objective!

Edited January 7, 2022 by Ed Stone

[knocker]

It’s fair to say that high pressure remains influential over the medium term once the ridge has been established. But the detail still remains elusive with, for example, the gfs indicating some quite complex energy distribution in the Atlantic which the ecm is not quite so keen on. Generally speaking a relatively warm anticyclonic airmass over the UK/western Europe which is not necessarily reflected in the surface temps

[phil nw.]

ECM view of the next  3 days.

Saturday looks quite a windy and wet day as some active fronts come through,there could well be a nasty back edge squall line with the cold front.Quite an unpleasant spell with squally winds and heavy rain for a short while could be seen.

Some blustery showers to follow in a colder westerly wind again.These gradually fading on Sunday under a weak ridge.This ahead of a weakening frontal system approaching from the west on Monday.This will introduce milder south westerly air as pressure rises from the south.

Beyond that high pressure looks like establishing around the UK locale but we await further confirmation of it's movement and exact positioning.This of course will impinge on conditions we experience at the surface wrt cloud/temperatures later next week.

[knocker]

A wet and windy day today as a frontal system tracks east across the country, clearing most areas by mid afternoon. Initia;ly some snow in the NW this morning and then later squally wintry showers in northern and western areas in the strong NW wind

A sunnier day for most on Sunday, albeit still wintry showers in the north before another frontal system arrives from the west with more rain on Monday

And then the well sign posted tpv/cold plunge down the NE North America, boosting the jet, splitting the upper trough and creating a cut off upper low, whilst promoting the subtropical ridge NE over the UK.  All leading to more settled and milder weather through the rest of the week

 

[knocker]

A quick glance at the ext mean anomalies this morning and the salient points. Aleutian trough/NW Pacific ridge extending into siberia adjacent to the tpv aligned north Russia > north Canada; a strong westerly upper flow exiting the eastern seaboard veering NW around the subtropical high pushing north to the Euro trough extending down to the Med.  Likely fairly dry with a NW/SE bias and temps a tad below average

 

[Methuselah]

Another fairly well-scattered set of GEFS 00Z ensembles, this morning: Rather gloomy inversion-pattern, at times, perhaps?

    

[Anthony Burden]

Morning all,Met office has Oxford temperatures in single figures throughout the coming week,a lot depends

on when pressure rise starts to influence the weather will it be overcast or clear.Inversion scenario can have a huge 

effect ie freezing fog frost etc will drop those temperatures substantially,lots to keep interest going short and 

medium range.

[phil nw.]

A glance at some UKMO charts for next week.

A bit of a change is on the way toward a drier and quieter spell after the last of the Atlantic fronts weaken early next week.They cross the country through Monday into Tuesday with any rain gradually dying out although it may leave a legacy of cloud for a while.

Tuesday T72 fax we start to see the promised high building north 

With the winds coming more off the Atlantic upper air temperatures will be on the rise as we head into mid-week as the flow turns more south westerly.At the surface though more around or just below average.

Continuing on through Weds. and Thurs the raw outputs show the high becoming established across England and Wales stretching eastwards into the continent.

Surface conditions subject as ever to cloud amounts and location.Scotland and N.Ireland are more likely to be influenced by the Atlantic flow over the top of the high so it will probably be little milder than further south.

If we get clearer skies under the high then surface temperatures would fall away with night frosts and the risk of freezing fog.This would also see daytime temperatures much lower of course.

Towards the end of the week indications that the high may drift away into the continent with the Atlantic moving closer towards the weekend. There are early signs that this could bring back the Atlantic westerlies and more unsettled conditions heading into week 2.

Now a couple of GFS mean charts for day 8.

GEF mean T192 850.s

The above showing colder conditions heading south as high pressure ridges in the Atlantic with a nw flow towards the UK.

A good ridge would bring a decent northerly at this time of year but we will have to see how this one pans out nearer the time.

[knocker]

The medium term anomalies this evening illustrate that very fine margins can make big differences to the detail at this range. Essentially it is about the orientation of the tpv, and in particular the lobe over northern Russia, in conjunction with the strong upper flow that suppresses the amplification of the subtropical high. Towards the end of the period both the gfs/ecm are struggling to retain this, thus trending towards a N/S split

[knocker]

A  fairly widespreasd frost this morning but still plenty of squally showers around in western regions, particularly the NW, where a little feature will produce a concentration of showers with snow in the mix, that will track south east through the morning/early afternoon.Elsewhere plenty of sunshine but cloud and patchy rain will arrive in the SW, courtesy of a warm front,  and then track north east through the evening and overnight

Monday is essentially about the warm front/patchy rain tracking NE and then on Tuesday the cold front clearing to the south east whilst the ridge starts to build from the soutrh west

And over Weds/Thurs high pressure becomes established over the southern half of the country amnd thus N/S regional variations

And out of interest a sounding for 12 Thursday

 

[knocker]

The salient points of the ext mean anomalies this morning. Ridge NE Pacific linking to Siberia, adjacent to tpv northern Canada > north Russia although there is some disagreement on the alignment of this which impacts on the amplification of the subtropical high in mid Atlantic This in turn impacts the veering of the upper flow to the Euro trough and thus the weather and temps of the UK. The latter likely below average but to what degree?

 

[knocker]

A rather strange Nottingham midday ascent including a 164kt jet

[knocker]

The gfs/ecm medium term anomalies are a tad tricky this evening. No significant changes upstream and still the tpv aligned north Canada > north Russia with a strong westerly jet exiting south of the former lobe. But during the period the ecm has a split flow developing as the subtropical high builds in mid Atlantic around a cut off upper low, and this opens the door for some unsettled weather to move east across the UK. Obviously in the unreliable time frame so just to be noted

[knocker]

The cold front clearing the south east midday Tuesday as the ridge starts building in from the SW

[knocker]

The frontal system currently affecting the country should be the last for a while. Today the warm front will track NE briefly introducing milder air whilst tomorrow the cold front will clear Kent during the afternoon whilst the ridge builds from the south west

And for the rest of the week high pressure is in charge and thus light winds and likely some morning frost and mist/fog. But a fair amount going on upstream with both the gfs/ecm running a trough up the eastern seaboard, boosting the jet and promoting the subtropical ridge

 

[knocker]

During the medium term the secondary tpv lobe northern Russia becomes well established but developments upstream are of more interest as the subtropical high in mid Atlantic gets a boost. Thus the strong upper flow tends to remain to the north of the UK resulting in a pretty dry period

[knocker]

A very grotty day down here at the moment in the warm sector with Stratus, drizzle and zilch vis. Here the travels of the cold front over the next 24 hours or so before the onset of drier and more settled weather

 

[knocker]

The different interpretaion of the handling of east coast storms and the knock on affects downstream

Edited January 10, 2022 by knocker

[knocker]

The mean anomalies this evening reflect the impact of the east coast storm(s) with the gfs retaining greater amplitude of the Atlantic high pressure and thus the tpv lobe having greater European influence and the UK temps a tad below average. NOAA not averse to this solution

[knocker]

The ext mean anomalies this morning have a familiar look. The salient points; Aleutian low/NE Pacific ridge extending to Siberia; adjacent to to tpv aligned northern Canada > north Russia; strong westerly upper flow exiting the eastern seaboard south of the Canadian lobe around the subtropical high amplifying to some extent in the eastern Atlantic. Likely quite dry with temps around average,

[mushymanrob]

59 minutes ago, knocker said:

The ext mean anomalies this morning have a familiar look. The salient points; Aleutian low/NE Pacific ridge extending to Siberia; adjacent to to tpv aligned northern Canada > north Russia; strong westerly upper flow exiting the eastern seaboard south of the Canadian lobe around the subtropical high amplifying to some extent in the eastern Atlantic. Likely quite dry with temps around average,

rather cloudy too?...

[knocker]

46 minutes ago, mushymanrob said:

rather cloudy too?...

A bit tricky at this range. Dependent on the structure and orientation of the HP

[knocker]

The storms over the NE/E North America and the jet profiles at t144