Models, teleconnections and nowcasting

[knocker]

The North Atlantic 500mb and surface analysis for midnight

Remaining cold with wintry showers over northern Scotland but broken cloud with sunny intervals further south with some showers. mainly down western regions. Perhaps some slight rain/snow moving towards NE Scotland late on

The rain/snow continues NE overnight, courtesy of the warm front  Cloudy and dry elsewhere

By midday Saturday there is a complex, neutrally aligned trough west of Ireland (previously described in greater detail) whilst the subtropical high builds over Europe. Once any rain has cleared northern Scotland  dry with sunny intervals but with the wind picking up in the west

Over Saturday night the trough intensifies and rain from the associated front will encroach western regions during the afternoon on Sunday. At the same time the wind will strengthen considerable in the west, albeit advecting warmer air from the south

By Monday there is a nasty low 963mb over Iceland with the associated fronts traversing the UK so cloudy with rain at time but with some sunny intervals

Things continue to develop to the SW/S on Tuesday but the UK remains dry and quite pleasant

Edited April 3, 2020 by knocker

[knocker]

According to the gfs the developments continue through midweek with another low tracking north to Iceland with the associated fronts bringing some rain as they cross the country, but continuing very warm

Edited April 3, 2020 by knocker

[knocker]

The detail may vary a tad but a similar story from the ecm vis the middle of next week

Edited April 3, 2020 by knocker

[knocker]

The GEFS mean anomalies are certainly not consistent at the moment

[knocker]

The tpv orientation for the last week of April on the EC weeklies update has a familiar look to it, and with the Atlantic looking relatively benign with high anomalies in Europe this indicates a quiet and pretty dry period

Losing the positive anomalies over Europe during the firs week in May so perhaps a tad more changeable

 

[knocker]

Further developments to the west next week continues to facilitate warm advection from the south

[knocker]

The North Atlantic 500mb and surface analysis for midnight

Once any early morning fog/mist patches clear it will be quite sunny in most southern and midland regions. A little more cloud further north, particularly northern Scotland, including some patchy rain, as the warm front is still close by

Any rain should clear all but the Shetlands overnight leaving everywhere dry

As can be seen by Sunday the complex area of low pressure west of Ireland has become quite an intense feature which is facilitating, along with the ridge to the east, advection of warm air from the south. Ergo a sunny and pleasant day. But fronts associated from the low will bring rain and strengthening winds into western areas by the afternoon and evening

The low continues to deepen and drift north to be close to Iceland 955mb by midday Monday. Whilst at the same time the fronts track across the country bringing periods of rain, interspersed with some sunny intervals

Generally dry with sunny intervals on Tuesday but quite windy in the north which is still under the influence of the trough.

After early mist has cleared another dry and sunny day for many areas on Wednesday but some patchy rain on the front that is linking the trough in the NE to further developments to the south west

Edited April 4, 2020 by knocker

[knocker]

The overview of the next five days from the gfs is generally dry and quite warm with the odd encroachment from the Atlantic

[knocker]

Similar story from the ecm for the last half of the run

[knocker]

There is still not complete agreement between the ext anomalies albeit they are all in the same playing field. The main discrepancy involves the structure and intensity of the tpv in relation to any amplification of the subtropical high in the eastern Atlantic.However it's not drastic and the indications are of a relatively warm and dry period

Edited April 4, 2020 by knocker

[knocker]

Although it's a bit chilly on the surface Lerwick is in the relatively mild air from around the base of the Atlantic trough

[knocker]

[knocker]

The North Atlantic 850mb temp anomaly and streamline analysis along with the surface, for midnight

The intense low to the west of Ireland will move slowly north today and overnight resulting in a warm and sunny day just about everywhere but fronts associated with it will bring rain to western areas this afternoon which will track NE/E this evening and through the night. The rain will be accompanied by strong winds, perhaps reaching gale force in coastal regions

By midday tomorrow the low is 953mb just to the SW of Iceland and once any rain from the cold front has cleared quite early it should be fairly sunny day with the odd shower. These may be heavy and squally over Scotland which is still well within the circulation of the low/

Overnight and trough Tuesday there are further developments involving the upper trough in the Atlantic and the subtropical high which reaffirms high pressure over the UK, albeit still a tad windy in the north west

Through Tuesday night and Wednesday the front to the NW will track slowly across Scotland thus cloud with some patchy rain, whilst elsewhere another sunny and warm day

Little change on Thursday, warm with plenty of sunshine of England and Wales but appreciably cooler in the north

Edited April 5, 2020 by knocker

[knocker]

According to the gfs remaining warm and generally dry thereafter but some patchy rain may ingress the the north and west as the odd weak system pushes against the ridge

 

[knocker]

The ecm makes a little more of the low next Sunday but the detail is of course not a done deal at this range

[Snowy L]

2 hours ago, knocker said:

The North Atlantic 850mb temp anomaly and streamline analysis along with the surface, for midnight

The intense low to the west of Ireland will move slowly north today and overnight resulting in a warm and sunny day just about everywhere but fronts associated with it will bring rain to western areas this afternoon which will track NE/E this evening and through the night. The rain will be accompanied by strong winds, perhaps reaching gale force in coastal regions

By midday tomorrow the low is 953mb just to the SW of Iceland and once any rain from the cold front has cleared quite early it should be fairly sunny day with the odd shower. These may be heavy and squally over Scotland which is still well within the circulation of the low/

Overnight and trough Tuesday there are further developments involving the upper trough in the Atlantic and the subtropical high which reaffirms high pressure over the UK, albeit still a tad windy in the north west

Through Tuesday night and Wednesday the front to the NW will track slowly across Scotland thus cloud with some patchy rain, whilst elsewhere another sunny and warm day

Little change on Thursday, warm with plenty of sunshine of England and Wales but appreciably cooler in the north

That is one of the most ridiculous scales for a temperature graph I have ever seen.

[knocker]

1 hour ago, Snowy L said:

That is one of the most ridiculous scales for a temperature graph I have ever seen.

You can always block my posts, many do, if it's causing you a problem

[knocker]

1200 UTC sat image

[knocker]

A lot of Ac, Ci and some Sc here now

[Zak M]

First post on here, gonna give this thread a little go.

A warm day today, with temperatures around 20c possible in the SE.

Overnight into Monday morning some frontal rain will start to push in from the west

This leaves Monday's temperatures peaking at 17 around London. Some showers might develop behind the frontal rain that passed by from the morning.

   

[knocker]

According to the gfs a front brings some rain to the UK on Friday

But perhaps more relevant is the low that has tracked NE passing south of Greenland

[knocker]

Some marked regional temp differences at the end of the week as the weak trough traces east

After that it's down to the track of the rogue trough mentioned above

 

Edited April 5, 2020 by knocker

[knocker]

The North Atlantic 500mb and surface analysis for midnight

The band of rain associated with the cold front will clear eastern England this morning leaving a day of sunny intervals and showers, the latter particularly concentrated over N. Ireland and western Scotland. Less windy than yesterday

Still the odd shower in the NW tonight but essentially a clear night with just the odd spot of frost by morning

A warm and sunny day on Tuesday but quite breezy in the NW where cloud will encroach with some rain by evening as systems continue to track NE to the west of Ireland

A very warm day for England and Wales on Wednesday but much cooler over Scotland where the weakening cold front will bring some patchy rain. The strong winds here will slowly abate

Things get a tad more complex on Thursday as a weak trough slips south east bringing some patchy rain to the south where it  is still warm with the old front stationary in the north

 By Friday the UK is under a shallow low pressure area with sundry fronts littered about so a very varied regional scenario which I will not attempt to detail

Edited April 6, 2020 by knocker

[knocker]

The qustion from this point is what about the weekend? The gfs this morning takes the deep low south of Greenland, it has it 10mb lower than Exeter and tracks it east south of Iceland as it fills bringing rain and strong winds to the north Sat/Sun as it passes. But in it's wake another low undergoes rapid cyclogenisis in the Denmark Strait and a front associated with this will further rain and strong winds to Scotland early Monday. So very much a N/S split but of course just one model in an area of unreliable detail

Edited April 6, 2020 by knocker

[knocker]

Predictable the ecm has a different evolution for the weekend as it develops the low south of Greenland and tracks it NE and then south east as the subtropical high amplifies in mid Atlantic

Edited April 6, 2020 by knocker