Short range model discussion - into 2018

[knocker]

The deconstruction of the trough and promotion of the ridge is pretty much cut and dried so a return to warmer conditions, certainly for the southern half of the UK. But there is still a fair amount of energy kicking about and the evolution detail for the rest of the week less so and is rather important this determines the position of the very warm air.

Edited July 28, 2018 by knocker

[knocker]

Outlook. Unsettled and cooler than of late becoming more settled and warmer again for most by midweek.

Currently a depression north west of the Hebrides is bringing rain to NW Scotland that will soon move away but further south another low has swept in from the south west and rain is already effecting much of Wales and western England accompanied by strong winds in coastal areas. Haven't seen a Camborne sounding like this for a while

The rain will move quickly north east during the morning, missing most of N. Ireland and western Scotland, clearing most places by early afternoon leaving a breezy showery regime in it's wake. And needless to say, much cooler

The main belt of rain will clear overnight leaving a few showers and Monday will be a mixture of sunny spells and showers but these may well become more concentrated and thundery in troughs within the westerly flow and still quite windy in the north but already warming up a tad in the south east.

With low pressure and an occlusion still fairly adjacent to N. Ireland and western Scotland showers and fairly strong winds will persist in these areas on Tuesday whilst remaining reasonably dry with less wind elsewhere.

Changes are afoot by Wednesday so time to sit back and take an overview which finds an upper trough stretching south in the Atlantic towards low pressure around the Azores with high pressure beginning to nudge into the south of England. On the surface this translates thus

By Thursday the upper trough has edged further east thus promoting the ridge and warmer and stable conditions into the south of England but still with the avenue for systems to track across the the north leaving it cooler and changeable in this area.

The NH profile at T120

[knocker]

The 0500 chart. A lot of moderate rain around

[knocker]

The 0600 geostationary neatly sums it up

[knocker]

The ecm not dissimilar to the earlier post midweek with frontal systems traversing the west and north with high pressure and warmer air pushing north into the south east

[knocker]

The high res. MODIS at midday and the analysis and chart. The rain has ceases here, albeit still cloudy

[Sky Full]

1 hour ago, knocker said:

The high res. MODIS at midday and the analysis and chart. The rain has ceases here, albeit still cloudy

The satellite image appears to show more cloud in the south east than in the west, for a change.....  And that fax chart looks unusually busy with the U.K. being affected by four fronts at the same time!   We have certainly seen the effects here today with bands of heavy rain moving across, although fairly briskly on gusty south westerlies.   Dry at the moment but the models indicate that some rain will persist in the west until maybe Monday midday.

[knocker]

Just now, Sky Full said:

The satellite image appears to show more cloud in the south east than in the west, for a change.....  And that fax chart looks unusually busy with the U.K. being affected by four fronts at the same time!   We have certainly seen the effects here today with bands of heavy rain moving across, although fairly briskly on gusty south westerlies.   Dry at the moment but the models indicate that some rain will persist in the west until maybe Monday midday.

Now don't get JH started on Exeter and their fronts.

[Sky Full]

2 minutes ago, knocker said:

Now don't get JH started on Exeter and their fronts.

Perhaps that's just one front, but segmented/fragmented....?  Anyway, it's well beyond my level of understanding so I'd better go and consult the text books!

[knocker]

16 minutes ago, Sky Full said:

The satellite image appears to show more cloud in the south east than in the west, for a change.....  And that fax chart looks unusually busy with the U.K. being affected by four fronts at the same time!   We have certainly seen the effects here today with bands of heavy rain moving across, although fairly briskly on gusty south westerlies.   Dry at the moment but the models indicate that some rain will persist in the west until maybe Monday midday.

I don't know how much rain/showers will be on the occlusion and the troughs in the circulation but the Icon's take on it

Edited July 29, 2018 by knocker

[johnholmes]

31 minutes ago, knocker said:

Now don't get JH started on Exeter and their fronts.

what me?

[knocker]

After the initial intrusion of the ridge later in the week the gfs is busy developing a heat low. Or so it appears

Edited July 29, 2018 by knocker

[chapmanslade]

42 minutes ago, knocker said:

After the initial intrusion of the ridge later in the week the gfs is busy developing a heat low. Or so it appears

That heat could result in some temperature records falling next weekend. It all depends on timing of the uppers and exactly where they end up, but the French record of 44.1C must be under threat. I'm in the Charente next weekend and just to the south around Bordeaux GFS is suggesting figures of around 42C at 14.00 which must give 43C or 44C a real chance around 17.00 French time. In all honesty with that and minima of 26C, outdoor activities are going to be restricted. Nice hot BBQ anyone ?

[knocker]

The 1800 geostationary. Perhaps a couple of Exeter's fronts?

 

[knocker]

By Wednesday systems are approaching south west Ireland tracking NNE whilst a ridge develops over the south of England. Meanwhile there is a shallow low over Iberia.

But from here onwards the movement of the Atlantic trough initiates some very warm advection from North Africa

[knocker]

The NH profile as of midnight. A quite intense upper low with the UK in a strong SW airstream with the block to the NE stretching west into Greenland.

The strong winds and rain have eased and moved away overnight although there is currently still some rain around over north west Scotland and some residual cloud in central and southern areas.

So today will essentially be a day of sunshine and showers with the latter more concentrated at first over western Scotland and then later running north east from the south west through Wales and the spine of England. Temps no great shakes but picking up in the south east

The showers will tend to dry out during the evening and overnight with Tuesday becoming a mainly dry day with perhaps the odd showers. But the main low to the north west with the associated occlusion has drifted quite close and thus N. Ireland and western Scotland will be cloudier and windier with some patchy rain and appreciably cooler than the south east.

By Wednesday we are slipping into the next phase of the pattern with the upper trough in mid Atlantic which on the surface relates to the next frontal system approaching south west Ireland tracking NNE and with the ridge gaining traction in the south east. Thus mainly dry with light winds apart from N.Ireland and Scotland and quite a marked NW.SE temp differential with latter continuing to warm up.

Thursday sees the waving frontal system over Ireland and the north and generally a much warmer day, particularly in the south east. It should perhaps be noted that this is all part of the process of the upper trough in mid Atlantic splitting and initiating some very warm advecion from north west Africa into Iberia,

Apart from some northern areas, which may see the odd shower, Friday will b dry and very warm, but hot in the south east once again

The NH profile at T120

[knocker]

This morning's updated fax charts Weds/Thurs and the ecm

It's worth noting the ecm NH profile at T120 because from this point the gfs and ecm start to differ, basically on the interpretation of the amplifying high pressure and the position of the upper trough in mid Atlantic which obviously is reflected in the surface analysis

[knocker]

A rather messy 1300 UTC high res Modis with a front lying down the western half of the country.

The medium term EPS mean anomaly this morning continues to indicate some ridging and positive anomalies in the eastern Atlantic with a Scandinavian trough. Thus much cooler over the latter countries than it has been of late with temps a tad below average but with high pressure being influential over most of the UK, albeit perhaps trending towards a N/S, it should remain pretty dry with temps still above average.

 

Edited July 30, 2018 by knocker

[knocker]

The showers today will tend to die out this evening but an area of more concentrated showery rain will track into the south west late on and move north east during the night clearing the south east by morning. It could well be heavy and thundery in places.

 

[knocker]

By Thursday frontal systems are traversing the north bringing cloud and rain to these areas whilst further the ridging from the south west is getting a foothold thus drier and becoming warmer. This evening's fax and ecm take on this

Over the next couple of days the surface ridge becomes an isolated high cell orientated west > east over the UK as pressure is exerted by the cut off upper low in mid Atlantic and energy tracking W > E  to the north of this. This will give a couple of warm days Friday and Saturday, particularly in the south but it's a rather precarious pattern.

 

Edited July 30, 2018 by knocker

[knocker]

The NH profile at midnight

Overnight it has been cloudy down the spine of England with showers tracking NE across the south and frontal cloud approaching western Scotland

The showers in the south east will clear during the morning leaving a mainly dry and sunny day for England and Wales but the aforementioned cloud and rain will move into N. Ireland and Scotland during the morning and later in the day and evening will creep into western parts of Wales and England also. Temps quite cool in the north and west but beginning to warm up again in the east and south east.

Overnight and though Wednesday morning patchy light rain will continue to effect the west bur matters are complicated by another frontal system that tracks into south west Ireland during the morning en route NNE. Thus cloud and rain pushing into N. Ireland by 1200 and Scotland later and becoming quite windy. Remaining cool in the west and north west but again warm in the south east.

Through Thursday the fronts continue to make slow progress NNE so cloudy and patchy rain remains the order of the day for northern and western areas but generally a warm day and very warm in the south east.

Over Friday high pressure in the form of the ridge from the south west becomes more influential and a very warm, locally hot, and sunny day ensues albeit still the odd shower over Scotland.

The pressure continues to build over Saturday and it's another very warm day, hot in the south, but, according to the gfs, it's as well to keep an eye on the upper trough in mid Atlantic.

And the NH profile at T120

 

[knocker]

Nice view of the current situation as the sun rises on the 0600 geostationary

[knocker]

Friday/Saturday

As with the gfs, worth keeping an eye on the Atlantic trough

[carinthian]

12 minutes ago, knocker said:

Nice view of the current situation as the sun rises on the 0600 geostationary

That so called cold front really struggling to make headway into the continent. Last nights min 21c and above in the low countries and Germany last night.. Looks like heat to build back again into France and Southern Britain as this week progresses as shown on the UKMO projections.

C

[knocker]

The EPS mean anomaly this morning. Consistent. And the 0900 UTC geostationary