Short range model discussion - into 2018

[knocker]

Nice high res. MODIS at 1110 UTC (courtesy Dundee Satellite Receiving Station) and the 1100 chart. Plenty of sunshine but temps and dew points noticeable down

[knocker]

METO max temp progression

Tomorrow 23C

Sat           24C

Sun          26C

Mon          27C

Tues         29C

Weds        30C

 

[Sweatyman]

24 minutes ago, knocker said:

METO max temp progression

Tomorrow 23C

Sat           24C

Sun          26C

Mon          27C

Tues         29C

Weds        30C

 

That for London Knocker?

[knocker]

Just now, Sweatyman said:

That for London Knocker?

No, not specifically. I suspect the will be other areas vying for top spot on some of the days.

[knocker]

A key factor vis this evening's gfs is the strong ridging in eastern Europe winch disrupts the trough to our east, creating cut off upper low to our south east, and allowing the rejuvenated Azores to connect with it to eventually form a very impressive block with the high [pressure consolidating in the eastern Atlantic.

[knocker]

Not a bad evening looking at the 1800 geostationary

[knocker]

My take on the medium term just to put the short range in context, The hot and sunny spell next week has been the percentage play for a while now with the orientation of the high cell the remaining consideration which is of some importance. A glance at last evening’s GEFS and EPS anomalies illustrate why this is not nailed down, perhaps because there is some uncertainty how the sub tropical high building in the south east US will effect the trough in the north west Atlantic. Anyway something for the det. runs to sort and in the meantime things looking good.

So back to the short range and this has been nailed down for a while and, as has previously been stated, basically over the next few days sees a gradual warming over the UK as the high cell moves east. So it’s really a matter of looking at the detail and keeping the waffle to a minimum.

With the UK still in the eastern quadrant of the high it has been a clear night but quite chilly in the light northerlies but it will warm up quite nicely during the day giving a warm and sunny day for most. The only exception being Shetland and northern Scotland where it will be mainly cloudy with some patchy rain as fronts skirt by to the north of the high cell.

Another clear night and dry and sunny day on Saturday and getting warmer except for the far north which will still be effected by cloud and noticeable cooler.

The progression continues on Sunday but still perhaps still the far north west cloudier and windier.

A quick reminder of the overall picture on Monday as there are other players in the mix who may play a role at a later date with the major trough to the NW still battling away with the strong jet running NE across the Atlantic.

But this does mean that the high moves a tad further east and Atlantic fronts just about impinge on the far north west

Not dissimilar on Tuesday but the movement of the high may just be enough to introduce an easterly component into the mix which could well augment any sea breezes in eastern regions.

 

[knocker]

UKMO in the same ball park as the gfs and then it's a matter of renewed ridging NE around the cut off upper low.

[knocker]

The ecm surface analysis at T120 and max temps Sun > Tuesday

Edited June 22, 2018 by knocker

[knocker]

Whilst sitting down at the beach this morning having an ice cream I was musing over the possible complications forecasting the max temps next week as one does on a Friday morning. My thinking was along these lines

There are normally four prerequisite conditions for very hot weather in the British Isles (loosely, maxima of 33–34 °C or above):

(i)   An established high soil moisture deficit (dry soil absorbs less solar radiation in evaporating moisture, leaving more energy available as sensible heat).

(ii)  A high solar angle.

(iii) A warm anticyclone allowing a feed of warm air from a hot Continent on a south or south-easterly flow.

(iv)  Anticyclonic subsidence ‘capping’ vertical mixing of strongly heated surface air.

The first three are okay and if the high cell parks itself over the UK for three or four days then we could easily get very dry subsided air not far aloft which could well reach the surface following entrainment owing to boundary layer turbulence. This turbulence comes about because the strong surface heating causes dry convection and this would have the effect of extending the boundary layer higher than normal. Thus in certain hot spots the max could well be higher than expected

Anyway, that's this morning's thoughts from Portreath

Edited June 22, 2018 by knocker

[knocker]

High res. MODIS at 1340 UTC ( courtesy DSRS) and 1300 chart

 

[knocker]

A cloud free zone on the 1500 geostationary.

[knocker]

At T96 an adjunct of the main Canadian/Greenland trough and the energy exiting the eastern seaboard again disrupts the Bermuda ridge and as the system moves east it performs two functions. Forming a trough in mid Atlantic which boosts once again the Iberian low whilst the pressure exerted on the UK high cell realigns it to the NE of the UK.

[knocker]

By T120 the gfs and ecm are differing on the Trough/ridge interaction. This needs to be sorted before confidence is high for the later evolution

[knocker]

ecm max temps Sun > Tues

[knocker]

The period of sunny, warm and then hot, weather has been nailed on for a while now so it’s merely a case of sorting the detail for the next few days. Currently the high pressure that is set to dominate the period is centred to the west over Ireland but over the next five days it will move east to be over the North Sea by midday Wednesday. During this progression temps will gradually rise before steadying.

It's been a relatively clear night in many areas with some cloud around, consequently quite nippy in places ( see WV and chart for 0300). But it will soon warm up into pleasant sunny day, albeit a fair bit of Ci is forecast, born out possible by the 250mb humidity chart and a forecast sounding which is very moist in the upper troposphere. The exception being the north of Scotland and Shetland where it will be cooler with some patchy rain, courtesy some fronts trailing around the high. This will be the case for the rest of the weekend through Monday

.

Sunday similar but getting warmer and perhaps minus the Ci

another sunny day on Monday and getting warmer, the usual caveat vis northern Scotland, but the high cell is nudged a tad further east under some pressure.

By midday Tuesday the high cell is now over the North Sea courtesy of continued pressure from the west where the eastward movement of the trough has temporarily disrupted the north east ridging of the high pressure. Still a warm and sunny day for the UK, albeit the temps tending to plateau.

Although another warm and sunny day is indicated for Wednesday the orientation of the high cell is now such that an E/SE wind component has been introduced and thus tending to the west/east split as cooler (relatively speaking) air is advected from the North Sea.

Edited June 23, 2018 by knocker

[knocker]

The ecm also pushes the high cell ENE mid week as it also becomes much less defined leaving the high pressure, the center of which is a long way to the south west, to renew the north east ridging around the Iberian low This it has to do against the backdrop of the energy still running east south of the trough in the north west Atlantic. Bottom line, a pleasant few days in store and quite likely some more to follow but not to get too carried away with detail at this stage. Looking forward to a trip up to the Somerset Steam Railway tomorrow.

[carinthian]

Great morning up date @knocker. Think your presentation is first class. The picture  below you posted again highlights the forecast high temps in the Manchester Basin. Its been a constant feature so far with these synoptics. Certainly does well t in that location with flow just south of east ( May be the longer land track comes into effect, or some local fohn off the high peak). Anyway ,our rather cool summer continues here in Eastern Alps. Looking forward to watching the cricket on Sky Sports at Old Trafford tomorrow, should be played under almost cloudless Manchester skies !

C

Edited June 23, 2018 by carinthian

[knocker]

Latest EPS 15 day rainfall figures

[carinthian]

Looking at that soundings chart for mid day over Northern England sort of confirms the current observations that show high cloud of some depth. With a surface wind still in a westerly vector , temps possible a bit disappointing under a opaque sky ( at a guess) . Think this upper moisture will dissipate tomorrow with much sunnier skies and temps nearer to 21c ( Manchester ).

 C

[knocker]

High res. MODIS at 1100 UTC

[knocker]

The MODIS overhead at 1245 UTC (courtesy Dundee Satellite Receiving Station)

[Mokidugway]

2 hours ago, carinthian said:

Looking at that soundings chart for mid day over Northern England sort of confirms the current observations that show high cloud of some depth. With a surface wind still in a westerly vector , temps possible a bit disappointing under a opaque sky ( at a guess) . Think this upper moisture will dissipate tomorrow with much sunnier skies and temps nearer to 21c ( Manchester ).

 C

I can confirm this cloud has some depth , a moribund day here

[carinthian]

1 hour ago, Mokidugway said:

I can confirm this cloud has some depth , a moribund day here

Hopefully, a sunnier and warmer day tomorrow @Mokidugway  in your part of the world. At least no rain bearing clouds ! Ground must be dry up north. My friend who lives in Skipton reports very little over the past 8 weeks with river levels much lower than normal.

C

[Mokidugway]

28 minutes ago, carinthian said:

Hopefully, a sunnier and warmer day tomorrow @Mokidugway  in your part of the world. At least no rain bearing clouds ! Ground must be dry up north. My friend who lives in Skipton reports very little over the past 8 weeks with river levels much lower than normal.

C

Indeed very little rain in the period and the ground is the driest I've ever seen here