UK meteorology

As a self proclaimed man of science surely you can appreciate the impressive G's the pilot accurately pulled for those testicles.
I'm no physicist, Tony, but you're right - he had to have balls to try that manoeuvre.:D

Anyway, my friend on Netweather has posted his latest thoughts regarding the week ahead, based, as ever, on some of the more reliable model outputs:
Today. The cloud and rain from yesterday has cleared and with a transitional ridge moving in most places will have a dry and sunny start to the day day albeit a bit nippy in the much colder air. Bur it is rather a brief interlude as the next system is moving east and the cloud from the warm front will start affecting the north west and then the the south west during the day. It wills be accompanied by rain which will as snow over the high ground in the north and particularly Scotland as the warmer air hits the colder air in situ. This will spread to all areas tomorrow as the wave and fronts traverse the country.



So on to the gfs this morning. First a brief overview. It is looking like being very unsettled this week and the beginning of next so the main concern will be rain and the possibility of gales.

After the above wave has cleared we arrive at the complexities of this week By 12 Tuesday we have a complex upper trough to the WSW running all the way down to north west Africa whilst another trough has slipped south between Iceland and Scotland and is about to phase with it. On the surface this translates to the main depression to the SW with the associated front running from Scotland down to west of the Azores on which a wave has formed to be west of Scotland 995mb at same time. This will bring rain (snow over the hills in Scotland although it maybe too far north) and quite strong winds as it tracks into the North Sea and deepens over the next 12 hours.



The front make little progress south as it comes up against the high pressure to the south east although far enough to introduce colder air over Scotland. Quite important this as another frontal low has formed to be 982mb just off the SW tip of Ireland by 12 Wednesday. Over the next 12 hours this deepens considerable and by 00 Thursday is 968mb over Ailsa Craig with gales and possible blizzards over the high ground in Scotland and strong south westerly winds and rain further south.





By Friday 00 the intense low has tracked into the west coast of Norway but the cold air behind does not get very far south on this occasion and the next systems that arrive, spawned by the large positively tilted upper trough also track east over Scotland which again could produce snow over the high ground



But the main trough continues to edge east and the next intense little surface low tracks across south England which greatly facilitates the ingress of the colder air to all parts of the UK by the weekend. The ecm starts differing with the gfs by Thursday when it is much more progressive with the upper trough which then deconstructs taking the main trough NE into the Norwegian basin and forming a cut off low to the south west of the UK. Thus the colder air is introduced over the UK much quicker in the north westerly gales and wintry weather behind the intense surface low.to the NE
 
F.A.O. Count - Met Office have a weather warning for heavy rain for your area on Wednesday:
Heavy rain is expected across north and northwest England on Wednesday. Spray and flooding on roads will probably make journey times longer. Bus and train services will also probably be affected with journey times taking longer. Flooding of a few properties is possible.
 
More from Netweather poster:
I'm not going to attempt the detail over the next couple of days as that can be found elsewhere so suffice it to say the main concern is rain, first in Scotland this morning and then later today and tomorrow in the NW of England as a complex systems of fronts and associated lows traverse the north of the country Elsewhere south of these areas cloudy, some sunny breaks and very mild. It topped 17C yesterday.





So on to this morning's gfs. At midnight Thursday there is a positively tilted upper trough orientated SW > NE to the west of the UK giving a complex surface analysis with small lows littered about and a marked delineation between the warm and cold air. Over the next 24 hours one of the lows to the west becomes more organised and tracks into Scotland and could well bring some snow in the mountains in the north and the associated front has tracked south to be over the channel with a link to the extended trough in the south west.



It is here that a little low develops and intensifies as it tracks NE to be 989mb over the west Midlands by 06 on Saturday It is quite possible the precipitation will fall as snow on the leading edge of the front over the higher ground in Wales and the Midlands as it engages the colder air but that will need to be sorted later as that's pretty much very dependent on detail. By 18 the low is west of Denmark and the UK is in a cool north westerly with wintry showers in many places, particularly the north and west, and the high pressure attempting to ridge north to the west.



I say the HP attempting to ridge north advisedly as it merely ends up ridging across the UK on Sunday, albeit it does cut off the cool north westerly as the next upper trough tracks east from Canada putting it under pressure and at the same time creating another complex low pressure area to the west of the UK with rain and front already over Ireland by 12 Monday. Over the next 24 hours the front traverses the country and the depression becomes more organized and by 12 Tuesday is 979mb approaching the western Isles and perhaps more snow to the mountains in Scotland.



To cap this we now have HP ridging (tenuously) north towards Greenland which forces the low south to be in the Channel by 12 Wednesday, Throughout these shenanigans the temps are around average, perhaps a little below.

The ecm doesn't agree with the gfs take for Saturday and has the front tracking south across France on Friday and no developing low to the SW to track north east. Thus the UK is already in the cool north westerly/northerly over Saturday into Sunday.
 
Updated weather warning from Met Office:
Chief Forecaster's assessment
Heavy and persistent rain is expected across parts of northwest Wales, northern England and southern Scotland on Wednesday before gradually easing during Wednesday night. Many places within the warning area will see 25-50 mm of rain, with around 100 mm possible over higher ground. Heavy rain will gradually clear eastwards during Wednesday night. There remains some uncertainty with regards to the exact location of the heaviest rain. Heavy rain will be accompanied by strong winds across many parts of the warning area.
 
"There remains some uncertainty with regards to the exact location of the heaviest rain. "

Bet I can guess! eh @JohnnyO

That's it Count, hit a guy when he's down ! We're presently living in what seems like living in low clouds must be like. Constant rain, poor visibility with grey mist and damp all round. Somehow your two foot thick walls seem strangely attractive.

JohnnyO. o/
 
That's it Count, hit a guy when he's down ! We're presently living in what seems like living in low clouds must be like. Constant rain, poor visibility with grey mist and damp all round. Somehow your two foot thick walls seem strangely attractive.

JohnnyO. o/
You might get something drier and colder over the weekend and possibly into next week as well, Johnny.
 
Models this morning appear to have changed completely - much more wet, windy and fairly mild weather next week now appears more likely:

Today and tomorrow can be best summed up as various low pressure areas and associated fronts will cross the country. The main features will be strong winds, gusts up 70mph in places, heavy rain with up to 100mm in places in the north, which will fall as snow overnight and tomorrow in Scotland.



So on to this morning's gfs. By 12 Friday the fronts and lows will all have cleared with a positively tilted upper trough which is deconstructing lying across the UK with main centre to the north east with Scotland within the circulation of the deep surface low giving snow showers in the north. At the same time high pressure is ridging north west of the trough. Over the next 24 hours a wave depression associated with front connected to the cut off low to the south west crosses France into northern Germany and thus initiates a cool northwesterly across the whole of the UK



Simultaneously another upper trough has been ejected from the Canadian vortex lobe (as can be seen) with the surface front orientated a long way south upon which waves are forming. So the progression over the weekend into Monday is for everything to move east with the ridge nudging into the UK on Sunday which is quickly suppressed by the front and depression tracking quickly east bringing snow to Scotland with perhaps some significant falls in the north. by 06 Monday



The low does not clear the UK quickly as two things occur, One it merges with the main trough to the north east and secondly the simultaneous amplification of the HP in the west forces the subsequent complex area of surface low pressure south briefly plunging the UK into a N/NE regime (unsettled but not particularly cold in the well mixed air) before the ridge topples across.



From here a strong westerly regime becomes the order of the day but this is looking way too far ahead.


The ecm in fair agreement up to the beginning of the week although it does take the wave on Monday a tad further north which would probably remove the snow threat in Scotland, but it also phases the low with the main trough to the north east and initiate high pressure amplification in the west

So by T168 there is also a complex area of low pressure in the vicinity of the UK generally centred in the North Sea being pushed slowly south, and the the UK in a northerly or northeasterly pretty well mixed airstream. Thus by midweek a wintry mix without anything horrendous.

From this point it differs drastically from the gfs as the ridge is strong enough to resist the east bound energy which is diverted to the trough in the south west which eventually promotes a high cell to the north of the UK. But again this is getting ahead of ourselves.
 
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