Short range model discussion - into 2018

[knocker]

The trough on Thursday and the showery, perhaps thundery, outbreaks through Saturday. and Sunday

Edited May 22, 2018 by knocker

[knocker]

Nice 1800 geostationary highlighting the not unimportant low west of Portugal

 

[knocker]

As we move through the end of the week and into the holiday weekend an overall summary of dry, warm/hot and sunny would not be out of order but must come with a couple of caveats relating to the specifics of the daily analysis. They are the regional temp variations and range and intensity of any convective activity, whether home grown or imported from the continent  

Today. It has been a clear night for most but the low cloud.mist eastern Scotland and the north east yesterday did spread further south and inland by this morning. This will burn back as the sun rises but will still affect NE/E coastal regions throughout the day so whilst elsewhere will experience another warm and sunny day temps in these regions will be depressed. Again there may be a few showers bubbling up in the south east this afternoon and late in the evening a more concentrated batch will arrive from the south east.

The concentrated band of showers associated with the trough will continue to track NW across southern England into Wales through Thursday and some of these will be heavy with the odd thunderstorm  So although another warm day is on the cards a fair temp variation denoting the specific analysis as be seen on the temp chart.

A quick look at the general pattern on Friday finds the Azores> Scandinavia corridor and the cut off upper Iberian low  in good working order.

and specifically the high cell is creeping NE NW of Ireland and the trough north over England and wales producing sporadic heavy bursts of rain all of which, on a basically warm day, does again produce some marked regional temp variations

By 1200 Saturday the high is north of Scotland and with low pressure pushing north the gradient tightens resulting in the easterly winds increasing a tad and thus on another warm day, warmer air has now arrived in the south,eastern regions will again be adversely affected temperature wise. Still a chance of the odd shower in the south.

Sunday a generally warmer day with the usual east coast caveat and elsewhere if sea breezes kick in, and a chance of thundery outbreaks in the south

Edited May 23, 2018 by knocker

[knocker]

Just catching up so the ecm take on some of the trough precipitation this week and the complex temp variations on Friday.

The 0900 geostationary (courtesy DSRS) showing the low cloud quite slow to burn back

[knocker]

Brilliant high res. MODIS at 1140 UTC (courtesy Dundee Satellite Receiving Station). The Algal bloom is still there

Edited May 23, 2018 by knocker

[knocker]

The 1500 UTC geostationary indicates the low cloud still very adjacent to the eastern coasts and this is due to ingress back further inland again tonight. Elsewhere glorious sunshine except the south east where cloud and showery rain associated with the trough to the south east of Kent has already arrived. This is due to track north west overnight and through tomorrow and could produce some heavy showers and some thunderstorms in south central and Wales.

[knocker]

Over the next few days the weather is certainly not without interest and that being the case nothing simple about it either. it was ever thus..

Overnight the low cloud and mist did creep back inland in the north east and a band of showers tracking north west associated with the trough/waving front that has pushed north from the continent, did produce the odd thundery outbreak, The mist/low cloud will retreat again during today but the showers will continue to track north west from the south east and there could be some substantial downpours, with thunder in the mix, anywhere on a line from Kent > north Wales and points to the south west of there. All of which depresses the temps in these areas with the best of the sunshine/temp mix western Scotland and down the spine of England.

Overnight and through Friday the front and shower belt continue to push north leaving the area south of it cloudy and quite muggy whilst further north, particularly western Scotland,  will get the best of the clear sunny weather with the usual caveat vis the north east coast. All of which gives a varied temp distribution.

So on to the weekend.

The transitional high cell is now to the north east and importantly this repositioning has achieved two things. It has allowed the low pressure to the south to push north whilst increasing and veering the easterly flow over the UK facilitating the advection of the warmer air, particularly in the south.This is underway on Saturday with the added complication of a trough bring some showery rain to the south west. This can be seen better on the 1000mb-500mb thickness charts. So a generally fine and sunny day and getting warmer

Sunday another warm day and quite humid with the chance of the odd thundery outbreak in the south and of course not forgetting cooler along the eastern coastline.

A very similar story on Monday

This is of course according to the gfs and it is noticeable that, although a tongue of the warmer air stretches north west over the UK, the main 'plume' is to the east. It will be interesting to see what the ecm comes up with. In any case, forby all of that, it looks being a pretty good weekend for most excepting eastern regions in Scotland and England.

 

 

Edited May 24, 2018 by knocker

[knocker]

Satellite 0614 UTC

[johnholmes]

1 hour ago, knocker said:

 

 

A very similar story on Monday

This is of course according to the gfs and it is noticeable that, although a tongue of the warmer air stretches north west over the UK, the main 'plume' is to the east. It will be interesting to see what the ecm comes up with. In any case, forby all of that, it looks being a pretty good weekend for most excepting eastern regions in Scotland and England.

 

 

The 12Z Fax chart above is ludicrous. Why on earth so many trough lines, and at this range no one, can have the faintest idea where any, if there are any, will actually be.

Senior man must have been on something last night in my view.

ignore it.

[knocker]

The ecm over Sunday to Tuesday gradually fills the low pressure and negatively tilts the high cell to the north east as it slips south east. This will tend to put most of the UK into a slack pressure gradient and alleviate the easterlies somewhat and possible help the north east, albeit the temps still down on a generally warm period elsewhere.

[knocker]

In conjunction with the latest fax the ecm take on the rain tomorrow

[knocker]

1 hour ago, johnholmes said:

The 12Z Fax chart above is ludicrous. Why on earth so many trough lines, and at this range no one, can have the faintest idea where any, if there are any, will actually be.

Senior man must have been on something last night in my view.

ignore it.

John whilst I totally agree vis the troughs is there any reason to assume the actual analysis is duff? I only mention it because it's not a million miles away from the ecm.

Edited May 24, 2018 by knocker

[johnholmes]

43 minutes ago, knocker said:

John whilst I totally agree vis the troughs is there any reason to assume the actual analysis is duff? I only mention it because it's not a million miles away from the ecm.

The overall pattern looks fine, I can hardly go against that from the Senior man at Exeter. It's just the splattering of troughs. Based on the science of meteorology I have to say, being very careful, it is not sound in my view. How can he or any computer generated data 5 days away do this with any meaningful accuracy?

[knocker]

17 minutes ago, johnholmes said:

The overall pattern looks fine, I can hardly go against that from the Senior man at Exeter. It's just the splattering of troughs. Based on the science of meteorology I have to say, being very careful, it is not sound in my view. How can he or any computer generated data 5 days away do this with any meaningful accuracy?

Oh I quite agree John and I also find the complexity of the frontal analysis on occasion, shall we say, a little daunting. And what can be quite annoying is that the trough over southern England does have support elsewhere. Onwards and upwards.

[knocker]

N. Ireland and the west coast of Scotland enjoy for a change. The 0900 geostationary

[knocker]

Another great high res. MODIS at 1233 UTC (Courtesy Dundee Satellite Receiving Station)

[Biggin]

Algae already in the N Sea ??

 

[knocker]

12 minutes ago, Biggin said:

Algae already in the N Sea ??

 

Yes indeed a large Algal Bloom

[knocker]

Overnight and in the early morning the showery rain and the odd storm across central England,, Wales and tthe south west will slowly move away and dissipate but a new batch on the swiveling front will impact the Lincolnshire coast and track north west across northern England, This will depress the temps in the aforementioned regions but they will rise quite well in the south east with the clearance. N. Ireland and western Scotland will again be warm and sunny being joined tomorrow by north east Scotland coastal regions as the onshore wind backs somewhat. Not unfortunately not affecting the English north east coast.

Edited May 24, 2018 by knocker

[knocker]

The ecm has a band of showery rain? traveling north into the south west Saturday evening and another a tad further east Sunday. {probably to do with this trough. (i know, I know)

[knocker]

A good illustration of the plume on Sunday with the NW 'tongue' over the UK

[knocker]

To begin this morning with a quick look at last night's EPS 5 day 500mb mean anomaly chart because IMO it illustrates very well how the major players, have come together to facilitate the analysis this weekend and the advection of the warm air from the south which should produce a fairly memorable weekend. Remembering the continuing evolution of the high pressure and the formation a few days ago of the last cut off upper low that drifted southeast west of Iberia.

Anyway on to more pressing maters

Currently there is a frontal system straddling the country and this going to bring bursts of showery rain, sometimes heavy with thunder in the mix, to the midlands, the north, Wales and parts of the south west during the day. N. Ireland and Scotland will have the best of the sunny weather but the south east will get quite warm behind the front which may trigger the odd thunderstorm. Thus the temps will vary across the country being a little depressed under the inclement weather, particularly in the north.

The thundery showers will tend to linger a while in the north early Saturday but elsewhere generally fine and getting warmer in the south as the unstable air over France pushes north accompanied by some thundery outbreaks which may well impinge on the south. North east coastal areas will again be cooler under the influence of the onshore breeze with the high cell just west of southern Norway.

Sunday will generally be another warm day (to emphasis again the model temps are not definitive but are a guide to variation) with again norh east and eastern coastal regions feeling the affects of the onshore wind. Thundery outbreaks are also likely to move across the channel and affect the south and south west. The 850mb chart shows very well the plume across eastern France branching north west across the south.

Monday a very warm day, hot in the south as the plume pushes north just to the east and again the chance of thundery showers popping across the Channel  Usual caveat vis the east coast.

a very similar day on Tuesday with the plume nudging slightly further east and maybe the odd thundery shower drifting a little further north

So in summation, apart from the odd blips mentioned above, this has the makings of a fine weekend for most.

Edited May 25, 2018 by knocker

[knocker]

The 0400 analysis showing a lot of moderate rain in the Midlands and quite cool in the north east.

[knocker]

The instability drifting north through Saturday according to the ecm

[knocker]

Forgot and Sunday afternoon