Short range model discussion - into 2018

[knocker]

The 1500 UTC geostationary

Edited April 5, 2018 by knocker

[knocker]

The GEFS 5 day anomaly and precipitation

 

[knocker]

I lost my earlier massif as my computer froze as I was about to post and no way was I going to plough through it all again so in order to keep track of the evolution I'll skip through and start at T48 00 Sunday.

Here we have the situation where the high block to the east is intensifying and edging NW towards the high area already created over Iceland, whilst to the west the upper trough has been relegated south over Iberia as the conduit ferrying energy from the eastern seaboard is reestablished  Thus a new upper low swings south east to join the one over Iberia, All of this leaves the eastern Atlantic and the UK in a very slack pressure area with various inflows leading to a showery day on Sunday with a complex surface temp structure.

By 1200 on Monday the two troughs to the south have phased but the next upper is in the pipeline to the west and, driven by a strong low level jet, is about to swing south east very adjacent to to Cornwall. In the meantime the UK remains in a rather benign showery regime albeit the temps slightly more uniform

Thus by 1200 Tuesday we find the pattern that is going to be most influential next week becoming established with the upper low west of Brest and both the European and Azores highs amplifying and establishing very positive heights north of the UK. The surface low associated with the trough is 991mb in the western Channel resulting in another showery day but much windier with temps just shading above average.

 

Edited April 6, 2018 by knocker

[knocker]

Within this time frame the ecm is not dissimilar to the above

[knocker]

The 0900 geostationary (courtesy DSRS) illustrates very well the complex area of low pressure to the west and associated fronts, the rain from which is currently affecting Scotland, Ni. Ireland and tip of Wales and Cornwall,

[knocker]

The movement and configuration of this upper low, in conjunction with the amplifying high pressure is quite important vis the evolution next week and at the moment there are sill differences in this time frame between the GFS and ecm,

 

[knocker]

The high res. MODIS at 1233 UTC (courtesy DSRS) I see some temps up to 15C

 

[knocker]

The rain over Scotland will tend to die out this evening leaving some patchy rain on the front further south but during the early hours and through tomorrow morning a heavier batch of rain will track NE from the western Channel courtesy of a wave on the front.

Edited April 6, 2018 by knocker

[knocker]

Well it could be worse

[knocker]

The 1800 UTC geostationary. It is the interesting area to the SSW that will produce the bursts of rain over the weekend and of course the warmer air will also drift NE

[knocker]

Currently there is a complex area of low pressure just to the west, and over the UK, stretching south as far as Iberia. Associated fronts will bring belts of rain up from the south to affect most pars of the UK at one time or another over the weekend whilst at the same time it will be quite mild. One such belt is currently over the south west and it will track north east during the day. Northern Scotland will stay dry but heavy showers will affect N. Ireland. Could well get quite warm in the south east if the sun shines.

Overnight the rain will persist in the far north but cloudy and mild elsewhere but by morning another belt of rain will affect the south east and move north and by 1800 we have this position. I'll leave it there for the minute as there are some problems with the GFS output this morning.

 

Edited April 7, 2018 by knocker

[knocker]

To continue from the above

Over Sunday night and into Monday patchy rain will persist in the south as the UK is briefly in a col with quite a varied temp distribution with a front across the south east. But at 1200 the next upper low is west of Ireland and about to swing south east against the block to phase with the trough over Iberia.Thus by 00 Tuesday there is a large negatively tilted trough over the UK stretching south which initiates not only more showery rain outbreaks but a south easterly surface wind.

By 1800 on Tuesday the upper phasing to the south is complete and there is a large associated complex area of low pressure over France with a myriad  of little centers dotted about with a strengthening easterly wind in the squeeze with the high pressure to the north east. This portends a continuation of the showery routine but the key issue here is really the temp contrasts in the regions subject to different surface flow. Thus the north east coast north of the wash to eastern Scotland will be decidedly chilly in comparison to elsewhere.

No huge change on Wednesday although the temps in the south east will be lower but changes are afoot but that is not for here. This is of course according to the GFS.

 

 

[knocker]

The sun rising on the 0600 UTC geostationary

[knocker]

Forecast sounding for the north east on Tuesday

[knocker]

Nothing to do with the current weather but an interesting image from a week ago

Ship and aircraft contrails are visible over the North Atlantic Ocean west of the Iberian Peninsula. Saharan dust can be seen off western Morocco. The island of Madeira is casting a cloud vortex street. Sediment from river run-off colours coastal waters.

http://www.sat.dundee.ac.uk/gallery/gallery_image.php?id=2383&size=m

[knocker]

The surface chart for 1000

[johnholmes]

2 hours ago, knocker said:

Forecast sounding for the north east on Tuesday

How depressing

[knocker]

The high res. MODIS at 1130 UTC. Cornwall just poking it's nose out and it's actually very pleasant here now. I see temps 16-17C in the SE

[knocker]

Rain persisting in Scotland this evening before clearing whilst another belt tracks NE into the south overnight.

Intrigued to see how this specific temp forecast for the south east works out tomorrow.

[knocker]

The UK is in a very slack pressure gradient at the moment with fronts loitering near northern Scotland and central southern England. Thus cloudy with patchy rain in these areas, particularly the latter, throughout the day. This will continue overnight but elsewhere where the sun breaks though it could feel quite warm although there is the risk of the odd heavy shower.

By the morning another wave is forming on the front and moving north bringing more persistent rai and this will affect all of England and Wales by 1800 whilst at the same time producing a fairly complex temp distribution.

So by 00 Tuesday we have the position we are all familiar with of the next upper trough swinging south east and about to phase with the trough over Iberia courtesy of the block to the east and amplifying high pressure in mid Atlantic (the key to the coming evolution). The associated low pressure has also consolidated  to the south of the UK initiating and easterly flow over the UK, albeit with different inflow sources, leading to marked temp differences N/S but particularly along the north east coast with CAA in the boundary layer creeping inland.

Over the next 24 hours, by 1800 on Wednesday, both the low to the south and the high cell to the north consolidate so the quite strong easterly is maintained and the temp contrast is even more marked with indeed quite unpleasant conditions north of the Humber where dank conditions under leaden shies portend. Elsewhere perhaps some odd shower being generated.

There is a desperate need to get rid of the chilling easterly regime but through Thursday the block remains impervious to the large amount of energy still exiting from North America battering away at it

 

Edited April 8, 2018 by knocker

[knocker]

The GEFS N/H anomaly this morning illustrates very well the intense vortex/lobe over NW N, America, the very strong westerly upper flow exiting the eastern seaboard which diverges in the eastern Atlantic as it hits the block

[knocker]

A bit more detail ob the analysis  12 Mon > 00 Weds

[knocker]

As the sun rises the 0600 UTC geostationary

 

[NickyB]

Thanks Knocker. Supposed to be heading up to Lindisfarne area on Tues, staying in my camper! Not sure I fancy it now ?

[knocker]

32 minutes ago, Chill Pill said:

Thanks Knocker. Supposed to be heading up to Lindisfarne area on Tues, staying in my camper! Not sure I fancy it now ?

Yes I'm afraid your timing for a quick break there does seem a trifle unfortunate as it is turning out Chill Pill