Short range model discussion - into 2018

[knocker]

The 500mb and surface analysis for midnight. Two things to note here. The ridge nudging north east, and the different airmass is well highlighted on the Castor Bay sounding, and the trough over Greenland that is shortly going to become quite influential,

With the movement of the ridge showers have become concentrated in eastern and southern regions, perhaps spreading some way inland, and this will remain the case throughout today and still quite breezy in the south. The showers will be of hail/rain with maybe some thunder thrown in.Elsewhere with lighter winds and clear skies, after a widespread frost to start, a sunny and cold day.

Overnight the showers will continue in the east but with very light winds and clear shies a widespread frost by morning with perhaps some freezing fog around

Through Monday , once any fog has cleared, it will be a sunny and cold day but showers will persist in eastern areas, perhaps becoming quite concentrated on occasion.

By midnight Tuesday the trough mentioned earlier is plunging south east west of Ireland and the low over south east France is moving north, but struggling against the block to the east. Thus a straggling front to the west and note also trough activity in the western North Sea.

This process continues through Tuesday and the quite intense low is steered into the southern North Sea in it's struggle with the block.from whence it tracks north. Thus some wet and windy conditions for much of eastern Britain which could well be of snow in Scotland. Generally another cold day.

So by midday Wednesday the low is near southern Norway with the straggly front now bringing patchy rain to western regions. Dry elsewhere but still not particularly warm. But further to the west, off the eastern seaboard and on the western flank of the high pressure, TS Oscar is beginning to engage with the jet.

On Thursday a wave has developed on the front which will bring rain to Wales and southern and central England, albeit temps are now on the rise And to the west Oscar is on the move.

And the NH profile at T120 and as can be seen, all of this has initiated some very impressive WAA into Europe

 

Edited October 28, 2018 by knocker

[knocker]

As the trough digs south into Iberia on Tuesday, the low over France tracks north into the North Sea along the western flank of the ridge, bringing some wet and windy conditions to eastern Britain whilst initiating impressive WAA into Europe.

Edited October 28, 2018 by knocker

[knocker]

Outlook - Unsettled and temps below average

The 500mb and surface analysis for midnight. An anticyclonic squeeze

After a clear night, but still some shower activity in the east. today will start with a widespread frost and some freezing fog, particularly in the west. But this will clear fairly quickly resulting in a sunny but quite chilly day with still some shower activity in eastern regions.

This evening and overnight a repeat in western regions of clear skies and frost but in the east the shower activity peps up with an occlusion adjacent ito the coast and more widespread and heavy rain encroaches the south east as the low to the south east and associated fronts move north west into the North Sea. For the moment the rain associated with the complex trough in the Atlantic remains west of Ireland.

Through Tuesday the rain and quite strong winds in the south east will track north with a few showers likely further west and here the waggly front has nudged slightly east to be over Ireland. Generally still quite a chilly day with temps below average.

Overnight Tuesday the rain clears as the low moves into southern Norway leaving a somewhat complex low pressure area to the west of the UK on Wednesday that will initiate some patchy rain in western regions  Elsewhere should remain dry with temps maybe rising a tad but still no great shakes

The slack low pressure remains over the UK on Thursday and with a few troughs scattered about sunny intervals and showers are the order of the day which will still be quite cool with temps below average. But meanwhile moves are afoot out to the west where TS Oscar has hitched a ride with the developing trough tracking east from Newfoundland

From here and into Friday there is a major disagreement between last evening's fax from Exeter and the gfs so I will discard the latter for this post and await the ecm. Thus the low continues to deepen and track quickly north east, leaving Oscar to fill to the south west, and by midday Friday is 974mb to the west of Northern Ireland with the associated fronts bringing rain and strong winds to western regions of the UK.

The NH profile at T120

 

 

Edited October 29, 2018 by knocker

[knocker]

The ecm does partially phase Oscar with the trough resulting in quite an elongated structured low which then tracks north east to bring some very wet and windy weather to the UK on Saturday. Along the same lines as the fax albeit with some differences, the timing being one.

[knocker]

The 0600 surface chart

[knocker]

Hardly a cloud at 1300

[knocker]

Clear skies and light winds will continue in western areas resulting in a cold night with widespread frosts. But further east the showers, that have continued through the day' will pep up overnight as a weakening occlusion tracks west from the North Sea. And also. but by no means least, heavy rain and strong winds. associated with the low moving into the North Sea from the south east, will start to impact the south east after midnight.

Perhaps give Clacton a miss tomorrow

 

[knocker]

Not very impressive temps today

http://www.met.reading.ac.uk/~brugge/15.html

[knocker]

Still some uncertainty vis the intensity and track of the intense low at the end of the week

At T72 the ecm and this evenings fax are okay

And from here the ecm tracks it between Iceland and Scotland which is good but still a very wet and windy Frid/Sat for the UK with the emphasis on the west/north west

Edited October 29, 2018 by knocker

[knocker]

Outlook - becoming wet and windy by the weekend. As mentioned yesterday still some uncertainty vis the track and intensity of the low.

The 500mb and surface analysis for midnight and the WV image for 0300 which shows the incursion of cloud and rain from the low currently tracking into the North Sea.

A clear and frosty start to the day in western regions and it will remain sunny for much of the day although cloud will spread west in central areas and east further north. later But showers will continue in eastern regions, perhaps pepping up through the morning,and rain from the system mentioned above will track north before exerting into the North Sea by 1800 before reaching the east coast of Scotland. All in all a pretty cold day, particularly so in the east in the very breezy northerly wind on the west flank of the low.

Tonight a reversal from last night with the clear skies and some frost  in the east with cloud and patchy rain from the waggly occlusion encroaching western regions

This much the order of the day for Wednesday with cloud and patchy rain, from the odd trough/front littered about, in the west and north and dry in the east with temps improving a tad.

Overnight Wednesday and through Thursday a very similar picture with fronts scattered across, or adjacent to, the UK resulting in sunny intervals and showers, perhaps some longer periods of rain.and the temps still a tad below average

Over Thursday and Friday this morning's gfs continues to differ quite markedly on the evolution of the low with Exeter's fax updates last night so again I will discard the former and await the ecm.  Exeter has the low intensifying and tracking north east to be west of the Hebrides 961mb by 1200 Saturday and thus wet and very windy weather effecting the UK Friday/Saturday.

 

 

Edited October 30, 2018 by knocker

[knocker]

This morning's ecm is also at variance with the fax charts. It doesn't completely phase TS Oscar with the trough that has exited the baroclinic zone around Newfoundland and so we end up with quite an elongated low at T84 with the main center 966mb

Over the next 24 hours this complex structure tracks north east bringing heavy rain and strong winds to the UK through Friday evening and Saturday with the emphasis on the west and north west. Warmer than of late

[knocker]

MODIS image at 1140 UTC

[knocker]

Less than impressive temps today as the rain is just about leaving the Norfolk coast Although I must admit it was very pleasant up on Carn Brea early this morning.

Edited October 30, 2018 by knocker

[knocker]

The ecm on the weekend low.

[knocker]

Outlook – remaining changeable with temps slowly on the up

The 500mb and surface analysis for midnight

Today starts with quite a widespread frost in many areas with fog patches but warming a tad in the west where cloud from the front(s) has encroached with patchy rain into NW/W areas.This rain will make slow inroads east during the day but not getting that far so temps in the east much better than yesterday.

During the evening and overnight the band of rain will continue to track east and another band will also move north across the south east associated with another frontal system

So through Thursday cloud and rain will continue to effect central and eastern England with clearer weather and showers elsewhere.

By Friday the fronts and rain have cleared to be replaced by a transient ridge thus a dry and fairly sunny day, albeit the temps no great shakes. But out to west the deep low has arrived on the scene tracking north east and strengthening wind and rain from the associated front will effect N. Ireland and western Scotland by Friday evening.

By midday Saturday the low is 959mb NW of Ireland with the cold front across eastern Scotland and down the Irish Sea, It's fair to say the track and timing of this low has been a bit of a headache. Thus quite strong south westerly winds across the UK but stronger in the NW/W which is where much of the rain is also concentrated. And the south westerly airflow has introduced warmer air across the UK

And by Sunday we are back in familiar territory with the low now away to the north east. Amplification of the high pressure to the west, in combination with the block to the east, once again forcing the next trough south east leaving the UK generally unsettled with patchy rain around with temps around average, perhaps a tad above.

And the NH profile at T120

Edited October 31, 2018 by knocker

[knocker]

The 0600 chart

[knocker]

The high res. Modis at 1233 UTC. After a fine early morning here Ac and Ci, along with some large Cu started encroaching around 1100 and now a lot of Cu around. And right a cue a heavy rain shower is underway

 

Edited October 31, 2018 by knocker

[knocker]

Through this evening and tonight the front will continue to track unevenly east resulting in some moderate rain in places and perhaps the odd storm in the south west. Behind the front in the north west clearer with some showers and maybe some fog. Simultaneously another frontal system tracks north from the south east and by 0600 a pretty wet picture down the eastern side of the country. This is reflected in the temps by morning

Edited October 31, 2018 by knocker

[knocker]

A nice symmetry

The 500mb and surface analysis for midnight

The two bands of rain associated with different frontal systems currently effecting Britain will tend to coalesce over eastern England today and not clearing until late afternoon. Leaving this area quite wet whilst the rest of the country will enjoy  a large amount of sunshine with just a few showers in the west. Temps rather on the cool side.

Once the main rain has cleared a clear night is on the cards under a transient ridge, still a few showers in the west, resulting in a widespread frost by morning with some fog patches.

A similar scenario on Friday with the showers being restricted to the north west and another quite cool, nut not unpleasant, day. But by dusk cloud, rain and increasing wind, associated with the deep depression at 30W, will be effecting N. Ireland and western Scotland.

Over the next 24 hours the low is relatively slow moving but the fronts do traverse the country resulting in strong south westerly winds on Saturday with gales in the north and bands of rain, much of which will be concentrated to the north west and west. But on the plus side this does introduce warmer air.

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By Sunday the low is filling and tracking north of Scotland so still quite strong winds here with rain and patchy rain as well over Wales and central southern England as the weakening cold front meanders south east

Still the odd front front lingering in the vicinity on Monday but overall a pretty dry day with temps around average. But more to the point the next upper trough is tracking east on a strong jet and has quickly suppressed the ridge that built in the wake of the last low and is on it's way to deliver some more wet and windy weather.

And the NH profile at T120

Edited November 1, 2018 by knocker

[knocker]

The Modis at 1130

[knocker]

In the 'colder' air behind the front at midday

Edited November 1, 2018 by knocker

[knocker]

Outlook - unsettled and warmer than of late

The 500mb and surface analysis for midnight

A clear start to the day for all, still a few odd showers around in western Scotland, with quite a widespread frost. And this is the order for much of the day with plenty of sunshine and light winds, albeit still on the cool side. But by 1800 cloud and rain, with the wind picking up, will be effecting N. Ireland as the warm front, associated with the deep low 955mb at 30W, edges in.

Overnight everything is a tad further east and and the rain is into Scotland and north west England where it also becoming quite windy. Further to the south east still remaining clear with frost around again by Saturday morning.

The warm front quickly clears to the north east through saturday morning leaving the UK in a sweeping and strong south westerly and the warm sector so the rain may ease in some areas for a time but not the west of Scotland. The issue here is, as the low to the west fills and tracks NNE, how fast will the cold front move as it tracks south east? This is paramount when considering how much rain will fall in the north west.and below is just the wrf take on this. The upside of this is the south westerlies have introduced warmer air

Overnight and through Sunday the low continues to track NNE to be east of Iceland whilst the cold front weakens and more or less comes to a standstill across central England so patchy rain cloud and patchy rain here with showers in the north west.

But, as can be seen, over the next 48 hours a sequence is underway that has been touched upon recently.. The subtropical high pressure in the Atlantic ridges north west which, in conjunction with the block to the east, forces the next Atlantic trough that is tracking east on a strong jet to dip south east which results in a large negatively tilted trough just to the west of the UK.

Regarding the UK all this means is that on Monday the cold front is now forced north again as a weak warm front but generally dry and that by Tuesday a large complex area of low pressure resides just to the west with fronts struggling to move east so some patchy rain in western areas. Both days temps above average, perhaps significantly so in the south east on Tuesday.

 

The NH profile at T120

 

 

 

 

Edited November 2, 2018 by knocker

[knocker]

Started getting Cs and Ac encroaching about 1300 which is well indicated by the midday sounding an the high res Modis at 1300 UTC. Now virtually total Ac.

[knocker]

The rain is currently over N. Ireland and western Scotland and this will spread east and a tad south through this evening and tonight with the main band into the North Sea during the early hours. Thus some easing in the warm sector but by early morning the main band associated with the cold front is effecting N. Ireland and western Scotland. It will become quite gusty in the northern areas as well. Further to the south east clear skies will continue and thus temps will drop again.

[knocker]

Outlook - unsettled but the pattern is encouraging a W/E divide for the UK whilst at the same time promoting some quite unusual WAA in to Europe.

Meanwhile the 500mb and surface charts for midnight

Currently much of the northern half UK is in the warm sector with the moderate rain from the cold front over western Scotland. This will track slowly south east during the day and it will also be quite gusty for a while in central/southern Scotland. Further south again dry and relatively warm.

During this evening and overnight the front and rain continue to make slow progress before coming to a halt and easing as the filling low tracks NW of Scotland. Still quite a strong south westerly wind blowing across the UK, particularly in the north where it will be accompanied by showers, so a much milder night in the south east with no frosts

But further to the south west a wave has formed on the front, which now appears to have become double structured, and this along with rain will track north during Sunday effecting the south west and Wales during Sunday afternoon. Again the south east escaping whilst showers continue in the north west with temps above average

Over Sunday night and through Monday the wave continues north to be west of Scotland by midday and all of this skews the front back again so cloud and patchy rain will persist in western and northern regions  whilst the south east will continue to be dry and quite warm

By Tuesday the wave is way up east of Iceland and the front has staggered east across the country thus spreading the rain around a bit more but further to west the situation gas developed that has been touched upon in earlier posts. That is the upper trough in the Atlantic has tracked east and become negatively tilted to the west of the UK resulting in new deep surface low NW of Ireland and the associated fronts bringing rain into the south west.and the winds freshening once more. Temps above average, particularly in the south east

By Wednesday the upper trough is extended across the UK which portends unsettled showery conditions, perhaps some longer spells of rain, with some sunny intervals and temps still generally above average.

And the NH profile at T120

And I would like to add a further comment which pertains to comments made elsewhere yesterday. Whatever my weather preferences might, or not be, they are totally irrelevant to any discussion I post vis the model outputs and do not influence the latter one jot. Nor should they

 

Edited November 3, 2018 by knocker