Model Output Discussion 19th January 2014-18z onwards.

[cooling climate]

Well I certainly will not be waxing the skies just jet.I see no reason to

change my initial thoughts of rather cold with some hill snow next week.

Perhaps the chance of something more wintry further south from t168 onwards

but unlikely to see any proper cold laying snow until February now.

Just like the ECM op I have not been overlly impressed by it ens members

either this winter.

Anybody forget to mention the UKMO model tonight synoptics look ok but lack

of cold air is a problem.

[Allseasons-Si]

HOLY COW.. we should bring back snow watch  

And lamp watch too

[EML Network]

Well the 18z just goes to show what would happen it the initial Low pressure system merges with another, stalls and takes it's time to shift south. 

 

The cold air is readily mixed out and the really cold air stays far out to the East of the UK, we never really tap into it at all. 

 

I'd say that given the current output that rain is by far going to be the major concern. 

 

It's a case of rinse and repeat on this run, the Atlantic onslaught just shows no sign of backing down and round after round it's winning hands down over the block to the East, which just stays in situ. 

 

so the 12z showed a Bartlett beginning to take shape in the later stages, this run shows a relentless Atlantic steam. 

 

The Met Office clearly under the impression that the NW effected by the most unsettled weather with the SE seeing the best of the dry weather, which is indicative of somewhere in between the 12z and 18z GFS runs. 

 

And a classic + NAO outlook. 

 

Sadly I think this is going to end up as yet another missed opportunity and time is beginning to run out. 

[bluearmy]

Eml, why place so much faith in gfs ??

Anyone hanging around for the london ens?

[Cloud 10]

Well I certainly will not be waxing the skies just jet.I see no reason tochange my initial thoughts of rather cold with some hill snow next week.Perhaps the chance of something more wintry further south from t168 onwardsbut unlikely to see any proper cold laying snow until February now.Just like the ECM op I have not been overlly impressed by it ens memberseither this winter.Anybody forget to mention the UKMO model tonight synoptics look ok but lackof cold air is a problem.

 

UKMO looks pretty decent with low heights and thicknesses and sub -4 850's?

 

[nick sussex]

Very unusual to see complete agreement from all ECM ensemble members for the wind direction in De Bilt during the mid week period:

 

 

Then the ensembles in graphical format:

 

 

The coldest clusters appearing next Thursday.

 

http://www.weerplaza.nl/15daagseverwachting/?r=midden&type=eps_pluim

 

Further delving into those ensembles, you can see both the operational and control run are wind speed mean outliers and also gust outliers,for 31 into the 1st the suggestion being that the main clustering keeps low pressure further west or has a shallower feature.

 

Overall in terms of trends you could expect some westward correction in the ECM tomorrow aswell as a more favourable tilted low and shallower which drives more energy under the block, the deep cold cluster of about 45% suggests cold being advected westwards from further east and not circulating round the main low.You can see there are still a further cluster of-2 to 0 over there but the 45 represents a stronger signal for where the air would be sourced.

 

So I think we're at a crossroads here in terms of the best chance for the UK to see some appreciable snow and much colder temperatures however the real interest is still a little too far ahead and even though theres good support in those ensembles for a colder solution than tonights ECM operational run theres still the area to the north of the UK re shortwave activity that still could be problematical, you need the block sufficiently west to moderate the effect of any phasing between upstream low pressure and shortwaves hanging around Iceland.

 

Cautiously optimistic this evening especially if the east Pacific ridge can hold on for a while longer and delay the push east of the PV chunk out of Canada.

Edited January 23, 2014 by nick sussex

[Jason M]

Well I certainly will not be waxing the skies just jet.I see no reason tochange my initial thoughts of rather cold with some hill snow next week.Perhaps the chance of something more wintry further south from t168 onwardsbut unlikely to see any proper cold laying snow until February now.Just like the ECM op I have not been overlly impressed by it ens memberseither this winter.Anybody forget to mention the UKMO model tonight synoptics look ok but lackof cold air is a problem.

I tend to agree with this as things stand tonight. Marginal won't cut it this year either as the soil temps will be an issue.That said, it will be interesting to see how things develop tomorrow as I can see some interesting possibilities down the line. For the moment though the sledge remains stowed in the garage but the lifeboat remains close at hand!If you live up a hill or in the NE though, interesting times ahead. Down here in the SE a sleetfest I'd imagine

[Panayiotis]

It looks like the NAE has finally been trashed on the weatheronline website. 

Edited January 23, 2014 by Panayiotis

[fergieweather]

As things stand, the UKMO concerns re snow (though still insufficient confidence for warnings) are for the NE and also in the wrap-around across SW on Monday. Modified GM T+96 attached to illustrate this.

Edited January 23, 2014 by fergieweather

[damianslaw]

Tonights FAX chart for Tuesday is a cold wintry one for the northern half of the country - as the low is forced on a southerly path across the country allowing sub 528 dam air to invade down to the midlands. Indeed it is quite a snowy chart, all will depend on dewpoints with the air from off the N Sea rather than deep continent it does look quite marginal for low level snow, but I've seen far less promising synoptics deliver snow down to low levels.

 

Fast developments are likely to happen over the next 48 hrs or so - whether to a much colder and possibly snowier picture remains to be seen, but we are seeing the best chance of such a scenario occurring within the reliable timeframe all winter.

[karlos1983]

London 12z on the mild side then

Edited January 23, 2014 by karlos1983

[Cheese Rice]

As things stand, the UKMO concerns re snow (though still insufficient confidence for warnings) are for the NE and also in the wrap-around across SW on Monday. Modified GM T+96 attached to illustrate this.Screenshot_2014-01-23-23-03-18-1.png

 

Would it possible for your thoughts on any snowfall potential on Sunday please?

 

Yesterdays forecast was showing two big blobs over N.England/Scotland 

 

 

Today's forecast don't show the map just the forecast for selected cities on Sunday. 

 

I have a sleet symbol for Sunday where I am (Leeds Bradford airport 210M) 

[SMU]

GFS Ensembles coming on board- only scanned 1-9

 

but 7 & 9 look potent ( like the NAVGEM 18z)

 

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=144&code=7&mode=0&carte=1

 

S

[Joe Levy]

As things stand, the UKMO concerns re snow (though still insufficient confidence for warnings) are for the NE and also in the wrap-around across SW on Monday. Modified GM T+96 attached to illustrate this.Screenshot_2014-01-23-23-03-18-1.png

Are the snow showers being modelled as mostly on windward coasts or could they push further inland? Or is it too soon for that sort of detail to be picked up?

[Mucka]

London 12z on the mild side then

 

I take it you mean the Op and not the suit. 

 

Colder than the 00z set with the 31st almost an ice day according to the mean, hmmm.

[Captain Shortwave]

One thing is for sure, the weather from Sunday onwards will be headline news. Question is will it be further flooding or significant snow.

[karlos1983]

I take it you mean the Op and not the suit. 

 

Colder than the 00z set with the 31st almost an ice day according to the mean, hmmm.

Yes sorry, I wish the mean lol

[fergieweather]

Are the snow showers being modelled as mostly on windward coasts or could they push further inland? Or is it too soon for that sort of detail to be picked up?

Inland. All models (albeit likes of E4 are much better) are known to be deficient with inland shower penetration. Plus wrap-around likely a more coherent entity anyway. Edited January 23, 2014 by fergieweather

[SMU]

http://www.meteociel.fr/modeles/jma/runs/2014012318/JN84-21.GIF?23-18

 

Interesting update on the 18z JMA ( & note to all + IF)

 

Im starting to see the potential for trough disruption on this deep low

 

looks close at the 84 JMA shows the low sheared into 2- & a kink appearing over Scandi- If your looking for cold that's the best case scenario because the cold will flood SW to the UK quicker & then at the western end the separated main low swings south over NW france.

 

Look for this type of kink at between T 102 & 108 in the morning..... over NE England...

 

http://modeles.meteociel.fr/modeles/gens/run/gens-7-1-114.png?18

 

If that develops fast enough its rain to snow for the UK faster by day 5

 

Also watch out for the alignment of the DEEP DEEP cold from Russia at 120- that's still lurking in the NE heading our way but the GFS keeps missing it....

 

S

Edited January 23, 2014 by Steve Murr

[draztik]

Updated EC32 broadly in line with previous updates; a propensity for lower heights to our nw, with any negative anomaly in Europe fading as we progress through Feb. Temperature trending below average at the 5k level, before we lose the negative anomaly as we progress further into Feb.

Edited January 23, 2014 by draztik

[fergieweather]

Re Monday - yes, Dep Chief confirming likely easterly movement of wintry ppn into some southern-central areas with time (not expected disruptive for those districts at present), but current E4 PPN discrimination, albeit not yet to be taken too literally, highlights Bristol-B&NES- to S of M4 corridor; parts of Devon/SW Somerset etc at greatest risk of what could be disruptive snow/hail/ice issues (because potentially phasing with AM rush hr rather than because of amounts per se). I'm not allowed to copy the high-res charts; sorry... but it's an interesting signal.

Edited January 23, 2014 by fergieweather

[nick sussex]

The GEFS ensembles are mixed but there was one which stood out in terms of being very unusual number 16 at T156hrs shows a pool of - 8 to -12 uppers approaching Ireland from the wnw! That's incredibly rare to see the depth of cold surviving the sea modification.

 

That one also looks like a big snow event ! Feb 1996 revisited! A bit different in all honesty but its a slider which turns into a Channel Low.

Edited January 23, 2014 by nick sussex

[laheymichele]

Inland. All models (albeit likes of E4 are much better) are known to be deficient with inland shower penetration. Plus wrap-around likely a more coherent entity anyway.

Will this stand for the North Midlands Ian? Edited January 23, 2014 by laheymichele

[Mark Bayley]

The GEFS ensembles are mixed but there was one which stood out in terms of being very unusual number 16 at T156hrs shows a pool of - 8 to 12 uppers approaching Ireland from the wnw! That's incredibly rare to see the depth of cold surviving the sea modification.

 

That one also looks like a big snow event !

 

Yes, my favourite is probably number nine, and shows the potential of any colder snap to become a colder spell!

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=192&code=9&mode=0&carte=0 

[Joe Levy]

Re Monday - yes, Dep Chief confirming likely easterly movement of wintry ppn into some southern-central areas with time (not expected disruptive for those districts at present), but current E4 PPN discrimination, albeit not yet to be taken too literally, highlights Bristol-B&NES- to S of M4 corridor; parts of Devon/SW Somerset etc at greatest risk of what could be disruptive snow/hail/ice issues (because potentially phasing with AM rush hr rather than because of amounts per se). I'm not allowed to copy the high-res charts; sorry... but it's an interesting signal.

Thank you for this, very interesting. In a region where wintry weather is exciting no matter what the extent of it is, this possibility is certainly appreciated! It will be interesting to see how this develops