UK meteorology

Malcolm's thoughts part 1:
Little to add to the outlook that hasn't been said before. The battle between the energy out west and the block to the east continues apace resulting in very marked regional variations of weather and temps which can generally be summed up as a NW/SE split.





Meanwhile...................Cloud associated with yesterday's front is still lingering in places, mostly from south east Scotland down through the spine of England, with still the odd patch of showery rain around, but this will tend die out and the cloud to thin as the day progresses. Elsewhere it will be sunny, fresher and cooler in the north west but becoming increasingly very warm in the south east. This may well trigger the odd storm again. By evening more cloud and some patchy rain will effect north west Scotland as a warm front, associated with a low over Iceland, approaches.








Over Saturday night and through Sunday the warm front will track south east, fizzling out as it goes, so not much rain on it but cloudy and humid and misty conditions prevail behind it in the warm sector until the cold front clears the far north west later, Meanwhile in the south the temps will once more climb and it will become very warm.





 
Part 2:
Overnight Sunday and though Monday the cold front will stagger slowly south east long with some patchy rain whilst south of this temps will once more escalate, again emphasizing the regional differences.








A similar scenario on Tuesday. With low pressure still over Iceland and weakening fronts straddled across the country, the north west will be fresher with some showers whilst it will be very warm in the south east





A similar fayre on Wednesday with perhaps the odd storm in the east/south east.





And at T120 the NH profile with particular interest in the offshoot from the vortex and how this will play out


 
Heatwave updat - next Friday, Saturday and possibly Sunday likely to see a surge of heat - high thirties likely in SE and EA, high-twenties/low thirties elsewhere. Drought likely to continue away from north-western areas, with no rain likely in SE until mid-August.
 
Malcolm's post for this morning part 1:
It is useful to keep an eye on the short term NH profile and anomalies just so that we have a pretty precise idea of the framework within which the det. runs are operating. No big surprise that there has been little change of late with the dominant features remaining the trough to our west centred to the NW and the impressive block in northern and north west Europe, aided and abetted by low pressure in SE Europe.


Thus we have a brisk SW/SWS upper flow over much of the UK but little eastward movement of any Atlantic systems, allied to the strong north easterly drift of the much warmer air over north west Europe just to the east. All of which portends a W/E split over the UK with quite marked regional temp variations. It's this knife edge scenario and detail that the det. runs have to sort,





So on to the detail. Currently a cold front over Scotland, preceded by a trough,





is bringing cloud and some patchy rain, and these will move erratically and slowly south east during the day, There may also be some early cloud and mist in the south west but out side of the areas mentioned it will become a sunny and very warm day, particularly in the south east.











The front will more or less fizzle out over the midlands during the evening and overnight but there will still be some showery rain around on Tuesday so again some marked regional temp differences with it again getting very warm in the south.





 
Part 2:
A quick reminder of the overall picture on Wednesday, The main upper low is between Greenland and Iceland with the trough extending to the south east where a wave is forming on the front. This is due to track north east.





Wednesday will generally be another warm day and again very warm in the south east.





By Thursday the wave and associated fronts are over Ireland but any rain stays to the west but this general moment does drag some warmer air north over much of the UK resulting in a very warm day generally.





By Friday the front has made some headway east and we are entering W/E split territory with it again being very warm south east of a line roughly the Tyne to Dorset and now there is some risk of the odd storm being triggered,





And the position at T120




At T96 the ecm has the front associated with the wave, now absorbed by the main low, over Ireland and it's about to traverse the UK into the North Sea over the next 24 hours. Meanwhile NE of Newfoundland another low has formed and will track rapidly east, then north east, on the jet which is the result of the Polar jet and sub tropical combining in the western Atlantic.





 
I haven't posted the usual today, but here's a post showing the extreme temperature contrast between the massive European/Scandinavian ridge and the Greenland/Iceland trough, in addition to thoughts for us:
Interesting looking at the 06z GFS charts at T30hrs to see the distribution of heat going right up to N.Cape(Norway) at around 70N suggesting surface readings in the 20's C even right up there.


We can see the temperature contrast either side of the jetstream as it heads up the Norwegian coast line.





Plenty of red colours around the hemisphere with only Greenland standing out as the island of blue.


That Atlantic trough seems an almost stationary feature out west just modifying the heat somewhat for the UK from time to time especially further north and west but this is quite a notable dry period with any Atlantic rain bearing features quickly losing their strength as they move into the UK.
 
Malcolm's thoughts part 1:
As I've no doubt everyone is aware quite a complicated picture over the next couple of days, much of which will be real time observing, before a more mundane period sets in so this will merely be a simplistic outline.


It's been a pretty clear night for most





But for all that temps have remained high in many areas, still hovering around the 20C mark in the south. This sets the tone for the rest of the day which will be generally sunny and very warm, particularly in the south east where it will be hot. Cloud will bubble up and a few isolated storms could be generated in the east/north east. Out to the west the wave depression is tracking rapidly north and the associated front is over Ireland so cloud and patchy rain may impinge on N. Ireland and western Scotland later.








Overnight Thursday the aforementioned cold front moves slowly east and the general movement of the system to the west drags even warmer air up from the south thus eastern and south eastern regions could well be hotter than today. But this is complicated by storms also tracking north east and later the cooler air from the cold front entering the mix thus all the ingredients for some nasty storms developing in eastern areas with possibly, hail, lightening and localized intense rainfall if you catch one. The storms. cloud, etc is a complicating factor vis the max temp








 
Part 2:
By Saturday the cold front is in the North Sea with a complex area of low pressure to the NW/N thus a much cooler day for everyone albeit still some storms and showers around.





Sunday sees the next wave depression and associated fronts arriving from the south west so a generally cloudy, rainy day, with strengthening winds and certainly much cooler than of late.





The rain will generally clear by Monday except for N. Ireland and Scotland which may well still experience some heavy rain and quite strong winds





The NH profile at T120


 
On what, in my area could well the the hottest July day ever, with storms forecast for this evening, here are Malcolm's thoughts:
It has been a very warm and humid night for many with some storms still lingering in the east and cloudy over N. Ireland and western Scotland and the far west of England and Wales as the cold front edges in from the west.





And this will be the story of the day. Cloud and some patchy rain edging east but in the latter temps will rise very rapidly and it will become very hot, particularly in the south east but away from the west it will be very warm generally. This will trigger more storms as the day progresses and some of these could be severe but, as is the case with storms, pot luck where they occur. Thus there could well a fair amount of rain in a short space of time in some places. (the max temp may well depend on the cloud/storm distribution)











The threat of storms will continue through the evening and early part of the night but all the time the cold front, with patchy rain and cooler conditions, is tracking east and will have cleared everywhere, apart from Scotland, by 1200 Saturday leaving cooler and showery conditions in it's wake with a dramatic drop in temps in some places after today.
 
Part 2:
The threat of storms will continue through the evening and early part of the night but all the time the cold front, with patchy rain and cooler conditions, is tracking east and will have cleared everywhere, apart from Scotland, by 1200 Saturday leaving cooler and showery conditions in it's wake with a dramatic drop in temps in some places after today.











So by Sunday 00 something we haven't seen for a while, cyclonic domination, with an intense upper low south of Iceland





and another wave depression that is swinging around the main low by the same time is just south west of Ireland en route to western Scotland as it becomes absorbed by the main low. This, and the associated fronts, will bring rain and strong winds to most of the UK on Sunday and a much cooler day generally.








The fronts will have cleared by Monday and with the main deep surface low to the north west sunny intervals and showers will be the order of the day but the latter more concentrated in the north west.





With the main low drifting south of Iceland Tuesday will be another day of showers and sunny intervals but cloud and rain may encroach the north west late on


 
Our drought has ended over two months since the last appreciable rain, plus we've had a spectacular show of inter-cloud lightning from the elevated storms. The nearby UEA wether station, which showed 33C (91F) earlier is now showing 18C (69F)!
 
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