Models, teleconnections and nowcasting

[knocker]

A layer of Ac here at the moment with a break to the NW. A quick look at a forecast sounding indicates potentially unstable in the lower levels Over to you John H

[knocker]

This morning's ext anomalies continue to indicate the re-orientation of the tpv: abdication of the eastern ridge whilst increasing amplification of the Atlantic subtropical high. Although no signs of anything nasty lurking in the woodshed perhaps temps a tad below average

[knocker]

The fairly rapid surface analysis change later next week that I attempted to summarize earlier

[johnholmes]

4 hours ago, knocker said:

A layer of Ac here at the moment with a break to the NW. A quick look at a forecast sounding indicates potentially unstable in the lower levels Over to you John H

eh, why me?

Small Cu around here, about 2-3/8 most tops look 4-5,000 ft but an isolated one could be about 8,000 ft?

[knocker]

17 minutes ago, johnholmes said:

eh, why me?

Small Cu around here, about 2-3/8 most tops look 4-5,000 ft but an isolated one could be about 8,000 ft?

Just thought it was around your area

Cloud from the blasted front still effecting here

Edited March 20, 2020 by knocker

[johnholmes]

2 hours ago, knocker said:

Just thought it was around your area

Cloud from the blasted front still effecting here

Lovely day here k, bits of shallow Cu but the breeze takes the edge of things Td is 4 which does not help. I'm making the most of it as

1. the breeze will increase over the next day or two

and 2 No doubt the N Sea will send Happy Spring to us in the East/central areas with its lovely St!

[knocker]

8 minutes ago, johnholmes said:

Lovely day here k, bits of shallow Cu but the breeze takes the edge of things Td is 4 which does not help. I'm making the most of it as

1. the breeze will increase over the next day or two

and 2 No doubt the N Sea will send Happy Spring to us in the East/central areas with its lovely St!

Perhaps not too bad in the NE if the wind veers a tad

[knocker]

Apart from the front on Monday/Tuesday effecting the NW high pressure is more or less in charge over the weekend and through next week, But by the end of the week troughs to the west and south east attempt to influence matters so we need to see how that pans out

Edited March 20, 2020 by knocker

[knocker]

The ecm has a very different take to the gfs next week. It develops a lobe of the tpv over Greenland and tracks it east to merge with the trough to the SE of the UK. This shunts the high pressure east. Clearly this has to be resolved

[knocker]

This evening's ext anomalies all agree on the retreat of the tpv and the subtropical high amplifying in the Atlantic upstream of the trough over Iberia. But there is no agreement on the alignment and intensity of the latter so a watching brief until bthere is some firming up for a more detailed look

[knocker]

A dry and sunny weekend in most areas and although not particular warm feeling quite pleasant in the light winds.Not quite so much along eastern regions with the onshore wind or the south west where it very windy at the moment along with cloud from the ever present front. Later today more cloud will creep into western regions with perhaps some patchy rain/drizzle in the north west.

A clear night with a widespread frost tomorrow morning before a generally sunny day with the usual caveats regarding some coastal regions

Edited March 21, 2020 by knocker

[knocker]

On to the rest of the week

Monday > Wednesday the front(s) and belt of rain will continue to make slow progress south east but not getting very (how far is still up for debate)accompanied by quite strong winds in the NW whilst the rest of country should stay dry and sunny after frosty starts to the days

[knocker]

At the end of the week and over the weekend a trough tracks east from Greenland and then south east as the subtropical high in the Atlantic amplifies strongly again

[knocker]

The 0700 chart. Not very pleasant here with the wind gusting 50mph earlier

[knocker]

merely out of interest the max temps next weekend from the ecm det and ems remembering that detailed specifics at this range are not that reliable

 

[knocker]

The front still effecting the south west with the main cloud layer at Camborne around 6,000ft. And the very strong low level winds advecting 'colder' air. At the surface 100/25kts and at 964mb 105/53kts

Edited March 21, 2020 by knocker

[knocker]

A relatively tranquil period of weather over the next fewdays with some frosty mornings and some rain and strong winds in the NW. But at the end of the week a trough runs east from Greenland and then ducks SE as the subtropical high in mid Atlantic amplifies to bring a cooler showery period.The detail is of course subject to change

Edited March 21, 2020 by knocker

[knocker]

Omega Block

[knocker]

Fairly obviously the alignment of the ridges/trough combination are critical in the more unsettled and cooler outlook in the medium term

And in the ext period. although the amplification in the east disappears, the alignment of and the intensity of the Atlantic ridge still has a key role and there is as yet no agreement on this and thus also the surface analysis

Edited March 21, 2020 by knocker

[knocker]

At midday on Thursday the ecm surface analysis is not a million miles from the fax so taking it from there

Over the next couple of days the subtropical high ridges strongly north east resulting i the trough over Iceland tracking south east down the North Sea. On Friday a front will move south east down the country then giving way to a very showery day on saturday particularly over eastern regions

By Sunday the energy flows are once again quite complex so I'll just settle for: the ridge is now 'squeezed south across the UK

Edited March 22, 2020 by knocker

[knocker]

The ext anomalies this morning have the tpv re-aligned Alaska/northern Russia with the subtropical high amplifying in mid Atlantic flanked a trough to the MW and south of the UK/ There is no agreement on the detail of this but the signs are of a relatively benign period of weather

 

Edited March 22, 2020 by knocker

[knocker]

I haven't looked at the gfs this morning so a glance at the 06 for next weekend

Friday midday and the trough is  starting to slide south east to southern Norway. Thus a weak front tracking south on Friday with colder showery air in it;s wake and a generally showery and 'cold' day on Saturday

It diverges from the midnight ecm on Sunday as it continues with strong ridging NE whereas the latter tracks another trough south north of Scotland

 

Edited March 22, 2020 by knocker

[knocker]

This is the ecm det run at t192 with the subtropical high ridging strongly into Greenland and another trough sliding down the eastern flank. But the clusters do not really support this scenario so definitely a watching bruef

[knocker]

Excellent depiction of the clear skies in the ridge, apart from the frontal cloud in the NW, and the deep low between Iceland and Greenland

[knocker]

Whether this is true reflection of the rainfall from the slow moving over the next three days we shall see

On to the weekend/ On Friday the front is draped across the country as the trough starts to track south east

By Saturday the ridge regains some influence

But further amplification in the west backs the wind northerly and resulting in quite a wet day on Sunday

 

Edited March 22, 2020 by knocker