Short range model discussion - into 2018

[knocker]

I'm sure everyone is aware of the current weather situation so just a quick overview.

A moist, unstable airmass currently covers the UK and this is spawning some very severe thunderstorms accompanied by torrential rain and the danger of flash floods. During this evening and overnight these will be concentrated in central southern areas, the south west and Wales, but storms could also pop up elsewhere.

The storms will still be affecting Wales and the west Midlands overnight and through tomorrow morning but will be slowly moving north over north west England, N. Ireland and into south west Scotland during the day. Elsewhere another muggy generally cloudy night with the Haar not far away from the east coast but where the sun breaks through tomorrow it could get quite warm again.

 

 

 

Edited May 31, 2018 by knocker

[knocker]

First class image from the 1800 UTC geostationary

[Snowyowl9]

Some large rainfall totals in certain areas next 12 to 18 hours,alot of places still bone dry.

Had a quarter of sunday morning`s total so far that was extreme,looks dry for a gap now.

Edited May 31, 2018 by Snowyowl9

[knocker]

An update on last night’s medium term anomalies as I see them and what appears to be an upcoming major test of the very impressive block

The major players are the north Canadian vortex and associated trough into the north west Atlantic, which is connected to the main vortex N. Russia and cold European trough with in between the European and Azores still combining to formulate the strong ridge running north west into Iceland.

But the orientation of the trough in the north west Atlantic has shifted a tad north east which effectively diverts more of the energy exiting north America south around it, albeit it still diverges in mid Atlantic around the block and down to the Iberian low pressure.

So currently the UK remains in a very slack pressure area with high and low pressure to the north and south so likely the temp will remain above average but leaving the det runs with a lot of niggly regional detail to sort.

But the question is will this transfer of energy and movement of the trough eventually wear down the block?  Probably not rapidly?

On to a few more details

Over the next couple of days the UK will largely stay under the influence of the warm, moist, unstable air which is conducive to triggering heavy showers/storms with the possibility where these occur of localized flooding. As the airmass slowly shifts north, thus introducing quieter conditions in the south, then so will the showers/storms.

Currently there is still shower activity over Wales (the 0300 UTC geostationary WV)

whilst, apart from the north and north west, over the rest of the UK a muggy cloudy day dawns, But as heating gets under way convection will be triggered in many west and central areas spreading north and storms could crop up virtually anywhere. Where the sun appears it will actually get quite warm with the usual caveats vis Haar and the eastern coasts.

During this evening and overnight there will be a lull in the storms but another humid night with a lot of cloud around in central areas and the Haar ingressing inland again in the east. But as temps rise again tomorrow more heavy showers and storms are triggered concentrated more on central and eastern regions but spreading north west into Scotland where their could be some very intense stormy outbreaks. Another warm day but 'cooler' weather slipping in to the south west.

The overall pattern on Sunday sees the high cell to the north west becoming more influential with any residual showers mainly in Scotland and the north east but also that means back to a north easterly drift whilst elsewhere another very warm day.

Monday sees a marked west/east split with warmer conditions in the west with the chance of the odd shower but much cooler and cloudier in the east in the brisk north east wind.

Tuesday will be a generally dry and quiet sunny day but still with the west/east bias with more cloud in the latter half of the country

 

 

 

 

 

Edited June 1, 2018 by knocker

[knocker]

The 0500 UTC chart noticeable again for high dew points and widespread mist/haze

 

[knocker]

The 0600 UTC geostationary

[knocker]

This morning's ecm pretty much of a piece with last night's anomaly so the question remains if the Atlantic trough continues NE into the Denmark Straight will it allow the eastbound energy to push some fronts east over the UK?

[knocker]

The 0900 UTC geostationary (courtesy DSRS)

[knocker]

The  high res. MODIS at 1322 UTC

[knocker]

Showers and the odd storm currently affecting north central to southern Scotland and N. Ireland will mainly fizzle out this evening leaving many places cloudy and humid overnight once again with low cloud along the east coast, By morning clearer air is creeping in to the south west but another batch of pretty intense convection will swing north west into the east coast by tomorrow morning and move up into southern Scotland during the day. Varied temps but where the sun breaks through quite warm that could trigger more home grown storms in Scotland but as mentioned drier clearer air is ingressing the south so not here.

Edited June 1, 2018 by knocker

[knocker]

Good example of the jet exiting N. America south of the upper low and then hitting the block. But how will it unfold?

[knocker]

The 1800 UTC geostationary/ Looks pretty wild over Ireland

[knocker]

On Monday the high ridging east north of the UK runs up against the low to the east that temporally initiates a brisk NE flow over the UK and a cooler regime, particularly in the east

 

[knocker]

Today sees the start of the transition away from the current humid and unstable airmass to a clearer regime by Monday. But in the meantime it has been another cloudy and humid night in many areas with high dew points as noted on the 0200 chart and the 0300 UTC geostationary WV

So today will start cloudy in many areas but it will become quite sunny and warm in some, particularly north west Scotland and the south east which could easily trigger some storms, whilst the clear air will spread into the southwest/west. But another area of concentrated area of convection is already approaching East Anglia and points north and this will track north west during the day and places that catch a storm could see some intense rainfall and a danger of localized flooding.(even a couple of convergence zones on the fax

Sunday will be a very warm day with temps well above average in places and with much clearer air over Wales and most of England just a few showers impacting the south west on occasion, But still a tendency for showers and thundery outbreaks further north

The general pattern by Monday sees the Azores ridging strongly north east north of the UK wedged between the upper low in the western Atlantic and the extensive trough to the east. On the surface this initiates much clearer air over the UK but also a brisk north east flow which again will impact the eastern half of the country. Generally dry but still showers in the west, particularly N. Ireland and Scotland.

Plenty of sunshine Tuesday but the usual caveat vis the east coast.

A not dissimilar day on Wednesday but the onshore wind will have veered somewhat and some showers may creep into the south courtesy a weak front in the Channel

 

Edited June 2, 2018 by knocker

[knocker]

The ecm temp profile Mon > Weds and the 0600 UTC geostationary (nice depiction of the low south west of Ireland)

[knocker]

Currently there is a band of showers, sometimes coalescing into more organized periods of rain over southern Scotland and northern England whilst further south  generally warm and sunny and with western Scotland also still cashing in

 The showers/rain will hang around this evening  and then might even pep up a tad over the central belt of Scotland through the night and only slowly clear tomorrow. Elsewhere another mild night but not so humid before a warm day in many places, particularly in the south, and perhaps triggering a few showers.

Edited June 2, 2018 by knocker

[knocker]

The gfs this evening is again creating a cut off upper low west of Ireland as the burgeoning high pressure splits the Atlantic trough. So once again a large slack area of low pressure in the eastern Atlantic and western Europe sitting under the high cell

[knocker]

The ecm is slightly more positive in creating the cut off low a little further east than the gfs and this period is quite crucial to the following evolution. In particular the merging of said low with the low pressure to the south and whether the Azores to the west will resist a permanent channel

[knocker]

There was some disagreement on last evening’s det. runs on if, and when, energy tracking east south of the Canadian/NE North America/southern Greenland trough complex will slowly erode the European/Azores block and introduce Atlantic systems into the mix over France and the UK. The short term anomalies do not provide an answer but they give a good overview, imo, of the problem

In addition to the aforementioned trough complex the main players are the main vortex lobe in the eastern Arctic and associated east European trough underpinned by the European high pressure ridging into Greenland. And to complete the mix, the Azores high/Iberian trough combo to the south.

Currently the energy exiting N. America is diverging in mid Atlantic as it encounters the block, leaving the eastern Atlantic and the UK in a slack pressure area with high pressure to the north and low to the south which would portend temps still above average and the probability of mainly dry weather during the this period.

Which is where we came in. Will the energy eventually create a conduit, via the trough in the west,  through the block and forge another link to the Iberian trough? We shall see what today brings forth.

Back to the here and now.

The persistent rain still over central and southern Scotland will continue for a while before slowly petering out this morning. Elsewhere a mainly clear start to the day, but not so humid as of late, continuing on  to give a warm and sunny day in many places,  which could well trigger some storms in Scotland and east/southern parts of England. These may continue to pop up during the evening before dying out.

 

Through Monday night and through the day cooler air is introduced behind the decaying fronts slipping south and this will initiate quite a marked west/east split on Monday  and in the warmer and sunnier west showers again could well pop up whilst the east suffers some more from low cloud and mist from the onshore wind.

The overview on Tuesday sees the Azores ridging north east whilst getting a gentle nudge from the trough to the west with the Iberian upper low still in situ. Which on the surface translates to a fine dry day but again with a west to east bias with a continuation of the light onshore winds.

Wednesday sees no significant change over the UK so again dry and warm/caveat east coast, but the trough over northern France is creeping closer, and to the west the trough has made some progress in splitting the ridge.

By Thursday the trough is still sitting to the west with the UK remaining under a very slack gradient which portends another warm and dry day but with the possibility of it being cloudier in the south with some thundery outbreaks as the aforementioned trough takes closer order.

And so the battle continues with nothing particularly sinister lurking in the woodshed according to the gfs.

 

 

Edited June 3, 2018 by knocker

[knocker]

Signs this morning from the GEFS anomaly that the trough continues to make headway east

 

[knocker]

The 0600 UTC geostationary

[knocker]

The ecm continues to be more decisive with the eastward movement of the trough at T72 but followed immediately by further amplification of the Azores which creates an intense little cut off upper low west of Ireland that by T120 is merging with the Iberian trough Which on the surface puts another slack area of low pressure over the UK, centred to the south west which portends some unsttled weather towards the end of the week in southern areas

Edited June 3, 2018 by knocker

[knocker]

The high res. MODIS at 1122 UTC (courtesy Dundee Satellite Receiving Station)

[knocker]

The MODIS at 1310 UTC. There is some complex medium and high cloud here after a pretty good morning, courtesy of that trough I would imagine

[knocker]

Any showers currently affecting N. Ireland and Scotland will fizzle out tonight but may return tomorrow in what will be another warm day in western areas. Not so in the east where the low cloud and mist that can be seen currently ( 1500 UTC geo) in the North Sea will ingress inland during the night and hang around in many eastern areas tomorrow.