Short range model discussion - into 2018

[Man With Beard]

Yes it looks as if most areas are going to escape this storm completely (save the usual winter gales on southern/western coasts), but there's still this nagging problem that the storm will be deepening as it crosses the UK and E England (Norfolk in particular) still needs to keep a very close watch - slight earlier deepening that forecast could make an enormous difference.

The EURO4 is perhaps the best we can look at for the shortest range - these are mean wind speeds - note how the storm has developed as it goes into the N Sea.

      

So expecting 60-70mph for S/W coasts and East Anglia, maybe 80mph in East Anglia if it bombs

[knocker]

According to the Icon the position of the low at 0200 with the  main rain belt through England and Wales with snow N. Ireland northern England and southern Scotland  The strong wind band over Wales, the Midlands and the south.

The winds will veer during the track into the North Sea and perhaps strengthen in the east of England.

[weirpig]

Gfs  takes the highest winds over Wales  the Midlands then in to east anglia   Around 60 mph ish   however even at this range still subject to change

[weirpig]

Arpege  Takes the Low through a similar track  but notches the winds up slightly  as it deepens.  winds close to 70 mph   across Midlands and East Anglia

Edited January 17, 2018 by weirpig

[FetchCB]

5 minutes ago, knocker said:

According to the Icon the position of the low at 0200 with the  main rain belt through England and Wales with snow N. Ireland northern England and southern Scotland  The strong wind band over Wales, the Midlands and the south.

The winds will veer during the track into the North Sea and perhaps strengthen in the east of England.

That second chart shows the North East getting the rather scaled down version of the NorEaster that dumped 12 inches on Boston, especially those at elevation away from the coast such as Consett at 270m ASL

[knocker]

By midday tomorrow the low is over northern Germany and the extensive upper trough is to the NW/N and east of the UK which is back in a showery north westerly. Across the Pond the twin troughs are getting organized whilst the high pressure ridges somewhat in mid Atlantic.

Over the next 24 hours by 12 Friday, although the UK is still in the showery north westerly, everything has moved east a tad, including the lows and frontal systems associated with the twin troughs off the east coast of N. America, and the warm front is now orientated WNW/ESE in central Atlantic.

Roll on another 24 hours to midday Saturday and the low has filled and slipped east allowing some transitional ridging and a very slack gradient over the UK which also results in a little cold pooling whilst at the same time the Atlantic systems continue to track east under pressure from the twin energy flows and the warm front is now running southern Ireland to Cornwall.

So the questions are as the warm front moves further east and encounters the colder air, will it produce snow and if so where and how much?

Edited January 17, 2018 by knocker

[knocker]

Latest surface analysis

[chrisbell-nottheweatherman]

11 minutes ago, knocker said:

Latest surface analysis

Seems that our storm has yet to become a closed-circulation low?

[knocker]

5 minutes ago, chrisbell-nottheweatherman said:

Seems that our storm has yet to become a closed-circulation low?

Indeed but looking at some heavy snow in the north and southern Scotland and still very windy for a time further south.

[chrisbell-nottheweatherman]

4 minutes ago, knocker said:

Indeed but looking at some heavy snow in the north and southern Scotland and still very windy for a time further south.

Perhaps the FAX charts and surface analyses of this storm might be useful for demonstrating the effects of a surface low deepening rapidly around the UK rather than the usual set-up wherein it's already completed cyclogenesis and possibly started to weaken before hitting the UK/Republic of Ireland.  I for one didn't realise that low presure areas could present the possibility of severe wind and precipitation without a closed core.

[matty40s]

tis a thing of beauty

 

nullschool

[knocker]

The 1800 fax

[knocker]

Continuous moderate rain here with wind getting up in the last couple of hours WSW 32mph gusting 50

Edited January 17, 2018 by knocker

[Rocheydub]

1 hour ago, knocker said:

Continuous moderate rain here with wind getting up in the last couple of hours WSW 32mph gusting 50

Pretty close to what's happening here knocker. Wind has sufficiently picked up since 7pm and now is changing direction and went from a 2mtr temp of 3.5c to 10 c fairly quickly and expected to go sub zero by daylight! Great weather watching!

[knocker]

The chart above has updated and the low is now in the North sea after, I imagine, a very rough night in many places for various reasons. No snow in these parts but wet and very windy with a full gale for a time and gusts 60mph but now easing quite quickly and plenty of stars around.

Considering this was the low 54 hours ago (from midnight) all in all I think the models did a pretty good job handling it

Edited January 18, 2018 by knocker

[knocker]

Once the storm has had a final flourish this morning as it move rapidly into Poland and points south east the next couple of days can be best summed up by saying the upper trough that has been so influencing our weather will slip slowly south east and by 12 Saturday be in the this position with some transient ridging to the west. But as also can be seen the next troughs are leaving the North American coast courtesy the two energy flows, one from the Canadian vortex lobe and the other across the southern US.

So what does this mean on the surface? This morning still very strong winds down the eastern side of England, perhaps gusting 75mph in coastal ares and reaching violent storm 11 in the North Sea before the low departs, Elsewhere back into the unstable north westerly and squally showers with hail in the mix,  mainly down down western areas and more frequent the further north you go. This will continue overnight and into to tomorrow with more wintry stuff in the form of snow in the north west as perturbations form in  the flow

But by 12 Saturday as the upper trough slips south east there is a very slack area of low pressure to the north and east of the UK which is under a transient ridge and quite cold air, whilst out to west the systems associated with the aforementioned upper troughs are tracking north east and the warm front associated with one low is now orientated southern Ireland to Cornwall.

As the the front continues to track north east it will bring rain to most but could well be of snow in the north and in Scotland with much milder air in it's wake.

 

 

Edited January 18, 2018 by knocker

[knocker]

The ecm also has snow on the leading edge early Sunday but it also forms another wave in the southern quadrant of the main low to the west of Ireland which is 990mb over NW Ireland by Monday 00 en route across norther Britain. Thus more rain and quite possibly more gales.

[knocker]

Something I skated over a bit earlier as the ecm had it tracking just to west of Cornwall is the wave that forms on the approaching front Friday/Sat and slips south east impacting Cornwall with maybe some heavy rain. There is no unanimity on how this will unfold, it would appear quite complicated with the fax running a double front structure.

[chrisbell-nottheweatherman]

35 minutes ago, knocker said:

Something I skated over a bit earlier as the ecm had it tracking just to west of Cornwall is the wave that forms on the approaching front Friday/Sat and slips south east impacting Cornwall with maybe some heavy rain. There is no unanimity on how this will unfold, it would appear quite complicated with the fax running a double front structure.

That's a new frontal structure for me!  Presumably the warm fronts are so close to each other that the ppn. will cover both?  Makes for a very expansive warm sector, though.

Edited January 18, 2018 by chrisbell-nottheweatherman

[knocker]

The low is currently causing a bit of mayhem in Germany where gusts of 90mph have been recorded in the NW.

[knocker]

Showers will continue overnight and through tomorrow again concentrated in the west and particularly the north west.

Late Friday and into Saturday morning a frontal wave will form on the approaching front and pop south east and bring rain to the far south west

The aforementioned front will continue to track north east bringing rain to most parts overnight saturday/Sunday but perhaps some snow in Scotland and the north as it meets the colder air.

By 00 Monday the front is in the North Sea but after some very brief ridging the next low is on it's way driven by the east bound energy and is duly over Ireland 990mb at 06 on Monday bringing more rain as it duly traverses the country en route to the North sea.

But it also drags in some very warm air and a marked thermal gradient latitudinally across the UK

Sidney...........................

Edited January 18, 2018 by knocker

[knocker]

Looks like Exeter may be slightly more progressive with front(s) on sunday

Edited January 18, 2018 by knocker

[knocker]

Sacre Bleu, the ecm is tracking another little wave into Cornwall and the south 0600 Monday.

Edited January 18, 2018 by knocker

[chrisbell-nottheweatherman]

6 hours ago, knocker said:

The low is currently causing a bit of mayhem in Germany where gusts of 90mph have been recorded in the NW.

Given that it's finally become a closed-centre low, perhaps the Met Office will name it?!  On the model, it's instructive to notice the closest isobars to the west and south-west of the centre on that surface chart.

[knocker]

Chris Meteo France named it storm David.

https://blog.metoffice.gov.uk/2018/01/18/should-the-met-office-have-named-last-nights-storm/