Models, teleconnections and nowcasting

[knocker]

Tonight's ext anomalies indicate a shift of an elongated tpv across northern Canada and quite strong amplificaton in the Atlantic arena. If this consolidates it would portend a dry period with temps above average

In line with the final warming?

Edited April 11, 2020 by knocker

[knocker]

The fax charts have not been updated since early yesterday evening so an abbreviated post this morning

By midday today the position is pretty much as postulated in previous posts with the brief phasing of the troughs as the subtropical high amplifies to the west.Resulting in pretty much a north south split with cooler cloudy conditions in the former and much sunnier and warmer in the latter. But heavy showers and storms breaking out in the vicinity of the weakening front.

These will tend to dissipate this evening but the south will become cloudy as the frontal systems track south leaving the north much clearer and cooler

Sunny and much cooler in all areas tomorrow as the high pressure becomes more influential but the fronts a little slow to clear the south coast where it will also be quite breezy

A sunny and relatively warm day on Tuesday but note the trough tracking east in mid Atlantic

Edited April 12, 2020 by knocker

[knocker]

From here we are with the gfs for the rest of the week.

Essentially the aforementioned trough crossing the Atlantic is disrupted by further ridging of the subtropical high resulting in the cut off upper low west of Iberia receiving a 'boost' and the surface low edging north which in turn disrupts the ridge and creates a high cell to the north of the UK

An overview of the weather for these days would be getting warmer again, apart from the north and eastern coastal regions, as an easterly wind component creeps in. And  more unsettled in the south courtesy of the movement of the low pressure

[knocker]

The ecm also engages  the troughs resulting in the low pressure to the south west supplanting the ridge over the UK by Sunday. Obvious the detail is a long way from being nailed for next weekend

Edited April 12, 2020 by knocker

[knocker]

The 0600 UTC sat image/ Quite a pleasant morning in these parts with some Ac and Ci

[knocker]

A thunderstorm warning out for N. Wales and the north midland where the latest fax is indicating a convergence zone

[knocker]

Snap, well nearly

[knocker]

A wave on the front at midday (solid Cs and Ac here but brighter now), and current radar/sat

Edited April 12, 2020 by knocker

[knocker]

According to this evening's gfs the low to the south west only has a passing impact before further amplification creates a high cell to the north of the UK

Edited April 12, 2020 by knocker

[knocker]

Predictable the ecm has a different take on this post t120

[knocker]

This evening's ext anomalies are indicating a tpv more or less over the pole with trough extensions eastern Europe N. Canada enclosing a strongly amplifying subtropical high in the Atlantic, the precise position of which is quite critical when it comes to the surface analysis

The spv

Edited April 12, 2020 by knocker

[knocker]

The North Atlantic 500mb and surface analysis for midnight

Any storms will have cleared by daybreak but cloud and some patchy rain associated with the front trailed across the country will linger a while this morning. Otherwise a mainly sunny and dry day as the ridge slips over the country but decidedly chilly with more cloud along eastern regions courtesy of the onshore breeze

Still cloud around in eastern and southern regions otherwise a clear night with a widespread frost

A sunny day on Tuesday and getting warmer, particularly in some NE regions

By Wednesday trough movement in the Atlantic that has previously been discussed is taking place and a cold front linked to the trough in the north will bring cloud and rain/drizzle the far NW. Otherwise another warm and sunny day after a frosty start

Things get a tad more complicated on Thursday as the trough to the south west and associated warm front bring some showery rain to the south. Whilst at the same time amplification of the subtropical high and the movement of the trough over Scandinavia drag the cold front south so colder over northern Scotland and some NE coastal regions

By Friday we are almost back where we started with the warm front draped across the south, with perhaps some heavy showers in the SW,  but much cooler air north of this, particularly eastern coastal regions with the onshore breeze

 

Edited April 13, 2020 by knocker

[knocker]

According to the gfs over the weekend the high cell to the north drifts east to Norway and thus enhancing the easterly component of the surface wind which will be quite brisk in the south by Sunday. But mainly dry apart from in the south west on Saturday where the low pressure is still exerting some influence

[knocker]

The ecm has a much more relaxed gradient next weekend with the high cell drifting NE and low pressure in the SW being a tad more influential. Some marked regional temp differences on Saturday

 

[knocker]

Currently

[knocker]

This is not a good analysis  if one is looking for some Spring warmth

[knocker]

Tuesday > Thurs with the ecm

After a chilly start with widespread frost in many areas not a bad day

Sunny and warmer, with some rain in the far NW

Colder in the NE and eastern coastal regions with showery rain in the S

 

Edited April 13, 2020 by knocker

[knocker]

A wind of 050/25kts at 997mb on the midday Nottingham sounding advects colder air in under the subsiding warmer air above. The temp is 6.8C at the surface, -7.9C at 857mb and +1.5C at 834mb

Edited April 13, 2020 by knocker

[knocker]

With some cross polar assistance the gfs establishes a strong high cell north of the UK resulting in gale force easterlies Well that's the theory

[damianslaw]

2 hours ago, knocker said:

With some cross polar assistance the gfs establishes a strong high cell north of the UK resulting in gale force easterlies Well that's the theory

Emerging trends models today is an easterly, from a cold source, very often happens late April.

[knocker]

Same charts for the ecm

[knocker]

The North Atlantic 500mb and surface analysis for midnight and the UK 0400 surface chart

After a widespread frost this morning it will be a dry and sunny day with any cloud mainly confined to areas with an onshore breeze which will also depress the temps

Apart from the far NW another clear night with ground frost by morning and the odd mist/fog patch

Another sunny day tomorrow apart, once more, for the far north west where cloud is likely to persist Warming up somewhat

The general pattern movement by Thursday has been discussed in previous posts  but in a nutshell a weak front tracks south over Scotland and thus cloudy but colder in it's wake and the low pressure to the south west edges north east to bring cloud and some rain to the south. Another warm day generally

Friday finds the low and associated fronts continuing to push NE bringing rain to Wales and southern England. Clearer bur much cooler to the north particularly the north east

The N/S divide continues on Saturday with a shallow low centred over the south west and thus rain here and still cool in the north, particularly again the north east in the onshore wind

 

[knocker]

According to the gfs this morning the first three days of next week are all about establishing a high cell north of the UK whilst at the same time tracking another trough across the Atlantic which 'tops' up the trough over France/Spain. Thus the UK is squeezed by this pincer movement with the wind having a strong easterly component but the eventual alignment of the main features is critical

[knocker]

For the same period above the ecm has a different structure for the main Atlantic trough with a breakaway element tracking east to the UK on Monday and as it happens, a pretty similar scenario for the UK by Tuesday although  this not the case for the overall pattern. Much still to be resolved

Edited April 14, 2020 by knocker

[knocker]

The EPS this morning has the tpv restructuring in the latter part of the ten day period which, with a lobe dropping into the NW Atlantic, facilitates westward movement of the high pressure north of the UK.

All of which 'coincides' with the final warming

Edited April 14, 2020 by knocker