Models, teleconnections and nowcasting

[knocker]

And again

[knocker]

Pretty much a N/S split with the weather today with the slow moving front bringing cloud and patchy rain to the south with clearer weather in the north but showery. Still quite warm in the south, particularly the SE, where the odd shower mat develop in the afternoon

A similar scenario tonight but two things to note. One; the feature over France pushing north and bringing more continuous rain to the south south and two; developments in the Atlantic that have been previously discussed

The feature mentioned above will bring cloud and rain to southern and central regions on Tuesday with showers continuing in the north but more in the way of sunshine

Developments in the Atlantic continue apace over Tuesday night and through Weds with the trough moving east and the associated occlusion will bring a band of rain, heavy at times. to most areas as it tracks NE across the country

By Thursday the trough is nestling over the UK and although the band of rain associated with the front moves away to the NE by morning another system develops in the SW quadrant of the trough and another area of rain will will encroach Wales and England during the day with showers and sunny intervals elsewhere

More developments in the Atlantic on Friday bring further rain to Wales and the southern half of England on Friday and Exeter have a convergence zone in the NE so perhaps some showery activity here. And to not the subtropical high zones are starting to amplify

Edited April 27, 2020 by knocker

[knocker]

To continue briefly with the gfs

The subtropical zones continue to amplify which drastically slows down eastward movement of Atlantic systems and with the Upper trough taking on a positive tilt, very warm air is advected into Europe which may just impinge on eastern England

But movement east does not cease entirely and the trough is far too close to the UK for comfort and developments within it bring yet more unsettled weather with periods of rain and perhaps some strong winds at the beginning of next week

 

[knocker]

The gfs Europe surface temp anomaly for the beginning of next week

 

Edited April 27, 2020 by knocker

[knocker]

The ecm gives for more prominence to the Atlantic ridge through the weekend with the trough shunted south thus still changeable but not with the same intensity as the gfs. But this variation does drag the warm air on a more northerly trajectory

 

 

[knocker]

I many ways the ext anomalies this morning are looking at a pattern similar to the suggestions for next week

That is quite amplified upstream with a strong ridge NW North America adjacent to the tpv northern Russia > Northern Canada but there is no agreement on the structure of the latter, Thus the disagreement continues to some extent downstream in the Atlantic/European arena on the intensity of the ridge/trough/ridge arrangement, albeit they are all in the same ball park  Broad brush indicators would suggest changeable but nothing drastic with temps around average

Edited April 27, 2020 by knocker

[johnholmes]

1 hour ago, knocker said:

The ecm gives for more prominence to the Atlantic ridge through the weekend with the trough shunted south thus still changeable but not with the same intensity as the gfs. But this variation does drag the warm air on a more northerly trajectory

 

 

Hopefully the EC will be nearer the actual weather

[knocker]

25 minutes ago, johnholmes said:

Hopefully the EC will be nearer the actual weather

Indeed John. We can do without any nasty little lows developing

[knocker]

There is only one cluster at t156 so no problem

But pick the bones out of them at 192. Of course the map projection doesn't help

Edited April 27, 2020 by knocker

[knocker]

Tuesday > Thursiday with the 0600  ecm

Edited April 27, 2020 by knocker

[knocker]

A good depiction of current conditions

[knocker]

No significant change from the gfs for the beginning of next week. Still very unsettled but of course the detail is long way from a done deal

Edited April 27, 2020 by knocker

[knocker]

And just to emphasise the point about the details the ecm disrupts the trough allowing the Atlantic back in

 

[knocker]

The cloud and rain associated with two low pressure areas to the NE/E, currently effecting much of south Wales and southern England will move slowly north during the day and start to become light and intermittent. Temps feeling quite chilly under the blanket of cloud but brighter with some showers over N. Ireland and Scotland

Overcast over Wales and England tonight with drizzles and mist but remaining clear with the  odd frost patch in Scotland. But the nex trough is taking closer order to the west

On Wednesday a band of rain associated with the aforementioned trough will track north east across the country reaching southern Scotland by evening with brighter interludes in it's wake

 By Thursday the complex trough is over the UK whilst another has tracked east to phase with it to the south west There are a myriad of fronts and troughs embedded in this unstable environment so sunny intervals and heavy showers are on the cards with thunder in the mix

The key point from here is the movement of the troughs as the subtropical high zones begin to amplify and by Friday the country is  more or less in a col with showers but warming up a tad

The evolution continues and by Saturday fronts from the low centre to the south west will bring rain to the south and there could well be some heavy showers over Scotland

Edited April 28, 2020 by knocker

[knocker]

According to the gfs over the next three days the subtropical zones continue to amplify as the main trough deconstructs and a cut off upper low is established just to the south west of the country. This is the main influence  resulting in unsettled weather edging east which will will, fairly obviously effect western regions more

 

[knocker]

The ecm has different ideas regarding the displacement of the upper low which results in a different surface analysis

 

[johnholmes]

Neither are much like what they showed for Sunday a couple of days ago!

 

Some indication on EC and GFS 500 mb anomaly charts of building heights S/E of the UK. When I get time later I'll have a closer look,NOAA seems less struck on that idea but a slight indication.

[johnholmes]

Tuesday 28 april looking at the 500 mb anomaly charts

Changes at least with ec-gfs; well ec shows quite a lot of change from a few days ago with +ve heights from Europe into the uk and a cut off upper low beneath it, gfs shows ridging and +ve heights nw of uk into Greenland with a suggestion of cut off upper low beneath this

Noaa has trough just w of uk and down off Iberia; showing some +ve heights east over Europe

Not similar enough to gain anything useful from them yet. It is a possible in terms of heights building over/e of uk perhaps?

 

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

sorry about the double link belwo can't delete it?

[knocker]

A look at the EC weeklies update for the last week of May and first of June

24 > 31

A benign tpv N Russia > N. Canada with a slack pressure area around southern Greenland, courtesy of the a trough/ridge combo., south of which  is quite a strong westerly upper flow. The abates in the east under the influence of positive anomalies which portends a dry period with temps a tad above average apart from Scotland.

01 > 08

The trough in the NW Atlantic losing any influence resulting a uniform and quite benign westerly flow across the Atlantic with temps much the same as the previous week with any changeable weather more likely to be in the NW

[knocker]

Take your pick over Sun/Mon as the trough disrupts, or indeed does it totally

And moving on to Weds where the det run had the European high amplifying NW between the troughs

Edited April 28, 2020 by knocker

[knocker]

The ecm this evening has the cut off upper low pushed along way south as the two energy flows push further troughs east across the atlantic at the beginning of next week

Edited April 28, 2020 by knocker

[knocker]

At the moment the UK is residing under a complex trough with another away to the south west. So a murky start to the day over much of England and Wales but clearer with showers further north. But a band of rain that has just reached Cornwall will track north east with clearer weather in it's wake.But there is a sting in the tail as another occlusion associated with the low south of Ireland will bring a showery, perhaps thundery,  outbreak to the south west by evening and here it's also becoming quite windy

A very unsettled night for most with bands of rain tracking north east followed by heavy showers which again could include thunder in the mix and increasingly windy

Tomorrow the frontal rain will be over Scotland and further south a mixture of sunny intervals and heavy showers with, again, thunder in the mix.These could well coalesce into longer periods of rain courtesy of any troughs embedded in the circulation.

By Friday the country is slowly slipping out of the clutches of the trough and the wind has abated but sill frequent heavy showers around with sunny intervals

By Saturday the country is in a col thus light winds but still some showers around interspersed with sunny intervals.But the subtropical zones are amplifying and to the west the upper trough moves towards a neutral tilt

But the amplification in the west is suppressed by the two energy flows as the process of creating another cut off upper low to the south gets underway. All of this results in a surface low developing west of Ireland and the associated warm front will bring rain the south west that will track north east on Sunday

 

Edited April 29, 2020 by knocker

[knocker]

According to the gfs over the next three days the combination of the energy distribution and he high zones manages to push the newly created cut off low north east which effectively means a continuation of unsettled weather over the UK

[knocker]

The front is just through here with a burst of heavy rain

[knocker]

Needless to say the ecm totally disagrees with the gfs vis early next week with the high zones holding sway