Short range model discussion - into 2018

[knocker]

The waving front

[knocker]

Tied in with the track of the deep low on Friday is the track and intensity of Leslie following closely on. The gfs at six  has it swinging and deepening NNE west of the UK, mainly because it has the upper trough a long way south and catches it with the jet but the 00 ecm is having none of this.  The consensus does appear to have it generally NE but without the rapid intensification, Of course the eventual track of the Friday low will influence this.

More detail on this very unusual storm

http://flhurricane.com/cyclone/stormspotlight.php?year=2018&storm=13

 

[knocker]

Interesting frontal cloud on the 1500 geostationary image

[knocker]

A familiar story this evening as the waving front continues to bring wet and quite windy weather to western Scotland with the rain probably moving north away from N. Ireland. Further south over England and Wales remaining rather cloudy but hopefully with the wind backing somewhat during the night a clearer day will dawn tomorrow.

Edited October 8, 2018 by knocker

[knocker]

This evening's ecm take on the Friday storm and secondary low and very active front could well produce some very inclement weather on Saturday/

Edited October 8, 2018 by knocker

[Sky Full]

2 hours ago, knocker said:

This evening's ecm take on the Friday storm and secondary low and very active front could well produce some very inclement weather on Saturday/

Those charts are quite graphic illustrations of the stormy conditions in parts of the Atlantic.  The first chart reminds me of a yo-yo being rewound on its string straight back to the hand holding it.  Where's the hand?  Right over the UK!  I suspect the intensity of that feature will have subsided quite a bit before (if?) it makes landfall in our neck of the woods though.

[knocker]

The pattern change that has been indicated for a while now really gets underway today with strong ridging eastern Pacific>Alaska>Arctic and the ejection of the vortex lobe N. Canada that initiates the plunge of the deep trough into the Atlantic in the next 48 hours as indicated by last evening’s EPS. Thus over the coming few days a very changeable picture albeit still tending towards the NW/SE divide

The 500mb and surface analysis for midnight

With the front still straddled across Scotland the persistent heavy rain has continued through the night across western Scotland and N. Ireland and this will continue through today, although gradually moving north and clearing the latter and remaining quite windy. Further south quite cloudy in many central and northern areas of England and Wales but sunnier further south and east and starting to warm up.

The front and rain will continue to edge north overnight with the rain finally clearing the far north just before dawn.

By Wednesday we are into opening comment territory with the Atlantic trough/European high amplification and a vigorous wave is forming on the front south west of Ireland but a corollary of this is the wind backing southerly and the UK catching the western flank of the WAA that has been initiated over Europe. Thus a sunny and very warm day for all and certainly a welcome relief in the western Isles.

Overnight and through Thursday the wave deepens and curves north forcing the cold front across the UK with patchy rain but temps still holding up okay. But away to the WSW another low is deepening rapidly and tracking rapidly east on a 150kt jet around the southern quadrant of the upper trough

This low proceeds to swing NNE west of Ireland portending some wet and very windy weather early Friday, in particular over Ireland, Wales and western and northern areas of England and Scotland.

The intense low quickly swings away north but another complex low has formed in the base of the trough and this also tracks NNE bringing more rain and strong winds to western and norther areas of the UK on Saturday. But temps are still above average in the south westerly flow, significantly so in the south east, where it remains quite dry.

And the NH profile at T120

Edited October 9, 2018 by knocker

[knocker]

The ecm for Friday and Saturday merely confirming a very windy and wet couple of days in most areas.

[knocker]

Two halves

[knocker]

The MODIS image at 1122 UTC (courtesy Dundee Satellite Receiving Station)

[Interitus]

22 hours ago, knocker said:

Tied in with the track of the deep low on Friday is the track and intensity of Leslie following closely on. The gfs at six  has it swinging and deepening NNE west of the UK, mainly because it has the upper trough a long way south and catches it with the jet but the 00 ecm is having none of this.  The consensus does appear to have it generally NE but without the rapid intensification, Of course the eventual track of the Friday low will influence this.

More detail on this very unusual storm

http://flhurricane.com/cyclone/stormspotlight.php?year=2018&storm=13

 

Very different a day later with the GFS having it do another circuit of the subtropical high in the mid-Atlantic then the 00z has it transforming into a deep low which passes south of Iceland while the 06z has it dissipating and absorbed into the trailing front to the south of the UK. In both cases beyond 10 days, might have some time to run yet. In the meantime it remains warm cored, becoming more symmetric and organised with time and may even restrengthen a little as it heads west to warmer waters again.

[knocker]

5 minutes ago, Interitus said:

Very different a day later with the GFS having it do another circuit of the subtropical high in the mid-Atlantic then the 00z has it transforming into a deep low which passes south of Iceland while the 06z has it dissipating and absorbed into the trailing front to the south of the UK. In both cases beyond 10 days, might have some time to run yet. In the meantime it remains warm cored, becoming more symmetric and organised with time and may even restrengthen a little as it heads west to warmer waters again.

And the ecm has it dissipating over Morocco at T144

[knocker]

A mostly clear night for most of the UK with perhaps a few fog patches in the south by dawn. But the rain in the north west of Scotland has a final hurrah with some more pulses along the front before clearing by around 0500

Edited October 9, 2018 by knocker

[knocker]

This evening the ecm has the low that has formed in the southern circulation of the Atlantic trough over Ireland by 1200 Saturday, and in conjunction with the front that is still linked to Leslie away to the south west. will bring some more wet and windy weather to the UK. By Sunday the front is in the North sea and Leslie is losing it's identity.

Edited October 9, 2018 by knocker

[Methuselah]

I wouldn't know what to do without your forecasts, Malcolm!

[knocker]

It's worth another look at the astonishing WAA into northern Europe in the near future

[Mike Poole]

I know myself and others have been chasing this warm spell on the MOD a few days ago, it's here now and is not in anyway record breaking as a few earlier GFS runs had suggested.  Instead  it is a notable warm spell for most of the south of the British Isles for the time of year, ARPEGE 12z here at T26:

Maybe the last taste of summery weather until next year, enjoy!  I will! Now roll on winter.

Edited October 9, 2018 by Mike Poole

[knocker]

Last night’s EPS anomaly does have the Atlantic trough edging a tad further west so always a possibility of more general unsettled weather over the UK but essentially still tending towards a west to east divide and with quite a long south westerly fetch of the upper flow some of the UK remaining within the influence of the WAA into Europe  that this pattern is likely to initiate.

On to more detail starting with the 500mb and surface analysis at midnight and an overview of the WV at 0300 which encapsulates this quite neatly

The upshot of all this today is that front. on which an intense little low is forming to the west of Ireland, has finally cleared the north of Scotland and with the high cell a way to the east the UK is under a southerly breeze so a warm and sunny day for just about everyone once any early morning fog/mist has cleared.

But systems to the west are edging in and a trough tracking north does bring some showery rain into the south west by early evening and later to other areas.

During Thursday the wave depression to the west has deepened considerably and is 961mb south of Iceland whilst the associated cold front traverses the country accompanied by a line of heavy showers, perhaps thundery. Remaining dry and quite warm to the east of the front

Meanwhile another low has formed in the southern quadrant of the intense upper trough and undergone explosive cyclogenesis and is tracking rapidly NNE west of Ireland. This and the associated fronts will bring some wet and very windy weather to much of the UK on Friday, but particularly the west and north. But pertinent to the opening comment, although i many ways irrelevant, temps quite a way above average.

Over Friday night and through Saturday another low forms at the base of the trough, fortunately no explosive cyclogenesis involved this time, but it does track NNE over Scotland and with the associated fronts will bring more rain and strong winds to the west and north with the south east probably remaining dry with temps still significantly above average.

The front(s) do eventually cross the whole of the country by Sunday so all areas are in a cooler airmass

And the NH profile at T120 is not a million miles from where we came in

[knocker]

A fair bit of mist around in England and Wales and cooler along the east coast

[knocker]

This morning's updated fax for Friday/Sat and apart from some very strong winds some significant rainfall is on the cards

[Badgers01]

42 minutes ago, knocker said:

 

 

Potential for a significant rain event showing for parts of Wales and the NW of England - that blob of 6”< of rain over the south of the Lake District must have caused some raised eyebrows at the environmental agency. If that conveyor belt of rain gets stuck over the hills there you can get some incredible accumulations of rain.

Edited October 10, 2018 by Badgers01

[knocker]

And Michael has now reached cat 4. Not looking good over the north east Gulf Coast

[knocker]

MODIS high res. at midday. Warming up nicely up to 23C

 

[knocker]

Michael at 1215

[knocker]

The 1400 chart. Must feel like high summer in north west Scotland. A fair bit of high, patchy,Ac down here recently

And for the US

 

Edited October 10, 2018 by knocker