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

[Frosty.]

I’m not sure the models over do the PV so much as underestimate blocking, as I say things remain on knife edge, stray just a little and all shall fall to ruin, or rather I mean we remain on the milder side of any cold and thus any snow will be localised and the cold not entrenched across the whole UK.

I think matt taylor said it could get a little bit colder next week with rain at times, could this be underplaying the potential perhaps? unless mogreps has imploded, the 00z models are telling me we will be plunged into deep winter during the course of next week with those mega height rises to the north east / north spreading out and the uk having snow event after snow event.

Edited January 24, 2014 by Frosty.

[Man With Beard]

ECM Ensembles even colder this morning in T120-T192 range, for example:

 

 

I note all models (except GFS) now sufficiently cold for snow throughout all of the UK by T144.

UKMO this morning demonstrates what could happen if the Atlantic is held up later next week ... Scandi block moves west ... does anyone else sniff the chance of a 1991 rerun?

[Frosty.]

ECM Ensembles even colder this morning in T120-T192 range, for example:

 

 

I note all models (except GFS) now sufficiently cold for snow throughout all of the UK by T144.

UKMO this morning demonstrates what could happen if the Atlantic is held up later next week ... Scandi block moves west ... does anyone else sniff the chance of a 1991 rerun?

I sniff January 1987.......Brrrrrrrrrrrrrrrrrrr

[nick sussex]

I think matt taylor said it could get a little bit colder next week with rain at times, could this be underplaying the potential perhaps? unless mogreps has imploded, the 00z models are telling me we will be plunged into deep winter during the course of next week with those mega height rises to the north east / north spreading out and the uk having snow event after snow event.

Frosty if only it was that simple! I suspect they may hold fire in terms of their tv broadcasts until shortwave issues are resolved to the north of the UK, that IMO is the only thing holding me back from going into ramp mode.

 

I don't think at the moment its the cold that will be the story but more the possible snow if things fall favourably, however we need to wait a few more runs because the phasing timing to the north and how far east any of this occurs will be very important to the UK in terms of cold undercut potential.

 

For this reason even though they may drop a few hints in the further outlook I can't see them saying too much at present.

Edited January 24, 2014 by nick sussex

[snowice]

What about  Carlisle?(only joking)

ECM Ensembles even colder this morning in T120-T192 range, for example:

 

 

I note all models (except GFS) now sufficiently cold for snow throughout all of the UK by T144.

UKMO this morning demonstrates what could happen if the Atlantic is held up later next week ... Scandi block moves west ... does anyone else sniff the chance of a 1991 rerun?

 

 

[shaky]

My word those ecm mean charts look even better than yesterday for undercutting and snow!!this could be memorable peeps!!

[snowking]

It doesnt get much better than this at 192 from an ensemble mean if it's snow-hunting you're in to:

 

 

Very positive trends this morning which could set us up for a very interesting start to February. Anyone concerned by the GFS det. should note it is much further North with the pattern than it's ensemble suite:

 

 

Still a way to go with this one yet - we saw just a short while ago how quickly things can fall apart in complex situations like this, but we are now seeing just how quickly fortunes can change for the better too.

 

SK

Edited January 24, 2014 by snowking

[beng]

 Scandi block moves west ... does anyone else sniff the chance of a 1991 rerun?

 

LOL - let's wait until it's t48 before bringing up Feb 91. Right now I'd say only Northern areas are most certain for snowfall. 

 

It's a different kind of setup IMO, as right now we don't have the Scandi hook jet modelled (my own terminology! - where you get a loop running up over Scandi, down through Russia and a streak back round through the UK in a loop) - that helps bring the really deep cold from Russia around the high. Instead we have a more powerful SE jet - so it'll be harder to bring in the really deep cold, but it could still result in a lot of snow if we get lucky.

 

Here's the jet pattern from 1991

http://www.meteociel.fr/modeles/archives/archives.php?day=6&month=2&year=1991&hour=0&map=3&mode=0

 

 

The further North and East you are, the better if you're looking for snow, but if the very gradual retrogression of the pattern continues, then the snow zone will expand.

Edited January 24, 2014 by beng

[Average Joe]

Frosty if only it was that simple! I suspect they may hold fire in terms of their tv broadcasts until shortwave issues are resolved to the north of the UK, that IMO is the only thing holding me back from going into ramp mode.

 

I don't think at the moment its the cold that will be the story but more the possible snow if things fall favourably, however we need to wait a few more runs because the phasing timing to the north and how far east any of this occurs will be very important to the UK in terms of cold undercut potential.

 

For this reason even though they may drop a few hints in the further outlook I can't see them saying too much at present.

As Mr. Ferguson repeats, but doesn't seem to want to be heard by some, rain amounts is their main concern at present!!

[East_England_Stormchaser91]

End of ECM, the HP over Scandi should be nicknamed the ohminator as the jet forms a pattern looking just like the ohm symbol We can say its living up to its name though with all the resistance to the Atlantic its providing!

[Cecil Hogmanay Melchett]

Given the ECM ensembles and the GEFS trend I would be shocked if the UKMO didn't change their outlook to at least include more uncertainty and more possible snow.

 

If we can get the low to sink favourably and the blocking  a bit further west then it does look like even with another pulse of a stronger jet out of the USA that this could be diverted se.

Agreed Nick

If we dont see at least a subtle change in the outlook  then i for one will begin to worry.

EDIT Im looking forward to the GFS06Z and impatiently waiting for the misery model to correct south.

Edited January 24, 2014 by Cecil Hogmanay Melchett

[Paul_1978]

very interesting model runs this morning lead me to one conclusion......... "Must...........resist........urge......to.....tell.......the family.........& kids........that....snow......is.......coming......"

*MIGHT* be coming. ;-)I'm staying very cautious until things get closer!!

[Downpour]

Lets face it the models and the Meto were forecasting heavy rain for the South East all today, as late as yesterday, and now it looks to be dry day.

Indeed they were. I think certain members would be wise to remember that before they try to close down debate on a weather forum. Great to have Ian F's updates but I'm sure even Ian is happy to be challenged. That's what it is all about.

[legritter]

Well things certainly looking rosy for us coldies ,becoming very Knife edge stuff looking at current models ,and then mid week next week thats 6/7 days away which is a long time in meteorology becomes possibly very productive .I will ceertainly be keeping an eye on that block to our n /east as it would only take a rise slightly higher than currently forecast to take us into real winter .But stand by your beds for many swings and finer details will appear each day .but pressure to our north and n/ east i think is the key .GFS good for possible detail out to 6 days ,but dont take last 3 frames of ECM too seriousely as these will change twice per day on a bigger scale .dont forget fax as this can give much more detail .And remember many a good snowfall in the uk is a result of Marginal synoptic situations .Now over too FROSTY for those colourfull charts .And  BOOM TIME ,CHEERS stELLAS ON ice .

[Weather Boy]

Has anybody noticed at 240h on the ECM12z the H-PRESSURE IS 1060MB. That’s going to make it hard for the Atlantic to break through, and February could spring lots of snowy surprises!

 

I stand to be corrected by those more knowledgable than me, but (counter-intuitive though this may sound) I don't think the block's "strength" is determined by how high the peak pressure is.  Although a weak HP can often be moved by stronger energy, very "strong" blocks can and do move and I don't think it's right to assume that a HP cell of, say, 1060 mb is less likely to move than one of say 1035Mb.

 

That's my understanding anyway.

 

As it happens, though, none of the models are suggesting that this High is moving anywhere soon.  Indeed, I wonder if that could be the problem because at present, we have a Russian rather than Scandi high.  Coldies are ideally looking for a migration towards Greenland creating a mega-block to our north causing a negative NAO and LP's being forced towards its low height buddies in the med, rather than their more traditional track around the Scotland/Iceland corridor.  If the HP can't be persuaded to move west, there's a risk that the colder flow stays in Scandanavia with us in the mild sector.

 

This happened last year, with a Russian high there forever in December 2012 and not moving west, despite the models wanting it to (hence, "it's coming!": unfortunately, no it isn't).

 

For me, that's the greatest fear of failure.

 

As for what the Meto say, I don't really think that they would need to say anything more than 'colder next week' to the general public, when things are a long way off.  Why bother when you might be wrong?

[Gibby]

Good morning folks. Here is the report on the midnight outputs from the big 5 weather models for today Friday January 24th 2014 lifted from my website at http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm

 

All models show a distinctly disturbed pattern as we move through the next 5-6 days with Low pressure slipping slowly down over the UK early next week to lie close to Southern Britain by midweek. I can more definitively confirm too this morning that it is going to turn colder across all areas next week allowing some of the rain to turn to sleet and snow, principally but not exclusively towards the North and East. Much of the rain and snow will be showery though a prolonged spell of heavy rain is likely to sweep East on Sunday with strong Westerly winds early in the week swing easterly by midweek over all areas except Southernmost Britain.

 

GFS then shows a brief respite in the wind, rain and snow later next week with frost at night for a time before further unsettled and chilly weather with rain at times and snow on hills return from next weekend onward to the end of the run with further snow at times on Northern hills.

 

The GFS Ensembles this morning show a period of colder weather on the way if not desperately so. Nevertheless with unsettled conditions continuing throughout there is plenty more distressing levels of rain shown at times with certainly some snowfall over the higher ground in particular before a trend towards more average temperatures but still unsettled weather is shown towards the end of the run.

 

UKMO today shows a cold Easterly flow across the UK through the middle section of next week with Low pressure just to the South. Outbreaks of rain across the UK will fall as snow in places with some accumulation possible over the hills, more especially but not exclusively in the North and East.

 

GEM today shows increasingly cold and wintry conditions next week with further spells of rain turning to snow giving some accumulations of snow at times, even in the South as cold Easterly winds undercut advancing Low pressure towards the SW of the UK.

 

NAVGEM shows the colder weather midweek with rain and snow clearing away South to be followed by a return to milder westerly winds and rain at times by the end of next week.

 

ECM shows an altogether colder feed of air across the UK as the North Sea trough backs West. the net result is a colder spell to come with spells of rain still bothering in amount at times across the South and West. In addition with colder air making deeper inroads into the UK from both the East and NW at times the trend towards rain turning to snow in places next week is an increasing one even in the South.

 

The ECM 9 and 10 Day Mean Charts show that the trough that has been shown down the North Sea, too far away from the UK to receive anything cold from the East pulled back West by 200 miles or so over the last day or so to lie down across the UK and on SE into Europe. This has increased the risk of cold weather developing widely across Northern and Eastern areas later next week with snow at times and with Low pressure areas expected to continue to slide SE down across the SW of the UK then some of this could extend to Southern and western areas too at times. The charts also indicate that there is unlikely to be much relief from flooding issues either with pressure values circa 1000mbs or less.

 

http://www.wetterzentrale.de/pics/Reem2161.gif

http://www.wetterzentrale.de/pics/Reem2401.gif

 

The Jet Stream is currently undergoing it's strengthening across the Atlantic, turning South to the West of the UK and then turning East across Europe. The flow diverted South to the West of the UK rather than over the UK (shown in recent days) is as a net result of colder conditions from Europe making more inroads into UK air space.

 

In Summary this morning I can easily declare this to be my most wintry report so far this Winter. With a shift West of the trough which has recently been lying down the North Sea recently looks like it is going to lie across the UK later next week. As a result the UK rather than the North Sea becomes the battleground for Low pressure areas bumping into the cold block to the East with cold air allowed to undercut from the East, all this following a Low pressure sinking South away from Southern Britain midweek with it's own mixture of rain and snow to get rid of. Snowfall will be most coherent across the North and East especially over the hills with rain rather than snow still most likely towards the SW. However, this remains unwelcome news as there remains little prospect of anything other than misery for quite a while yet for those flood stricken areas of my area in the SW with so much more precipitation of any form likely.

[i luv snow]

well there was an update from Meto early this morning for Sunday to Tuesday, which is a tad more exciting. I would imagine there will be a more wintry feeling Further Outlook today with the current output! From Meto:

Outlook for Sunday to Tuesday:

Wet and windy on Sunday. Colder thereafter, with showers or longer spells of rain, much of this turning increasingly wintry, particularly across northeastern parts. Staying windy across most areas.

Updated: 0308 on Fri 24 Jan 2014

"

[Frosty.]

Frosty if only it was that simple! I suspect they may hold fire in terms of their tv broadcasts until shortwave issues are resolved to the north of the UK, that IMO is the only thing holding me back from going into ramp mode.

 

I don't think at the moment its the cold that will be the story but more the possible snow if things fall favourably, however we need to wait a few more runs because the phasing timing to the north and how far east any of this occurs will be very important to the UK in terms of cold undercut potential.

 

For this reason even though they may drop a few hints in the further outlook I can't see them saying too much at present.

At least the met office are now cranking up the wintry potential for next week nick. especially for the north & east...this should be a golden time for coldies during the next few weeks and oh boy do we deserve it!

Edited January 24, 2014 by Frosty.

[shedhead]

Another step in the right direction for cold next week, with the chances of snow having increased quite a bit on the overnight runs, especially across the northern half of the country. No need to look any farther than today to see just how much trouble the models have when trying to bring rain eastwards into a cold block, even one that is centred 1500 miles NE of us, with the MO's forecast from only 12 hours ago pretty much bust as far as timings are concerned.

 

As of now though rain remains the main concern. Stalling fronts well might be great news if your #1 priority is an increased chance of sleet or wet snow, but areas that do not need the rain could really do with them pushing though as quickly as possible. Hopefully Sundays will be the last one, with Tuesdays diving SE into France....sorry Nick.

 

Edit-: Having declared my original cold, wintry Feb forecast dead, I would now like to officially reincarnate it...

Edited January 24, 2014 by shedhead

[Downpour]

As Mr. Ferguson repeats, but doesn't seem to want to be heard by some, rain amounts is their main concern at present!!

So questions about their mid range prognosis are invalid are they? Sorry I thought the UKMO did a MRF too - I could be wrong...

[UV-RAY]

Morning. The simple answer is us members can afford to be less cautious than the Met O. Take todays output for example. Now for days I have been saying the Met O forecast appears out of kilter with the output and this is especially true today. What is happening in the output is the models have backed away from what appeared at first to be a brief E,ly followed by milder W,lys. The output has been trending towards a more prolonged E,ly due to the block being stronger followed by sliding LPs. Take for example the ECM at +168. http://www.wetterzentrale.de/pics/Recm1681.gif What we have here is a low pressure moving SSE rather than W-E. This is a snow event as the fronts will be encountering cold air already over the UK but due to the track it will also pull in colder air on its N flank. Another trend im beginning to see is at +240 the models are wanting to increase heights towards Greenland. So in summary the main theme of todays output is a stronger block to our NE, Sliding LP systems.

Excellent post and great to see you posting again on a regular basis TEITS, as usual it's informative for both newcomers and old hands alike. Hope your keeping well.

[Duane S.]

Has anybody noticed at 240h on the ECM12z the H-PRESSURE IS 1060MB. That’s going to make it hard for the Atlantic to break through, and February could spring lots of snowy surprises!

 

It's very good indeed. Only one way forward from here..

 

 

In particular the energy dropping off the Greenland shelf by D10 not only looks to have left much weaker heights where the all conquering vortex once sat but it is dropping to the SW of us instead of through us. This is what we need to set up a potential cold spell as opposed to snap. Hopefully the Azores high moving away will become a continued trend, as we do need to.

Edited January 24, 2014 by s4lancia

[itsnowjoke]

Keep this just between us dont be tempted to tell any friends or family..espeacially the kids...as we tend to look a little puddled when it doesnt come off..but on the other hand when i havent mensioned the S word in the past and it has Sn##ed my kids are like " if your glued to NetWeather all day how come you didnt know it was gonna snow ?"....so either way i kind of look stupid.

[phil nw.]

Further signs this morning that the blocking is looking to extend west later holding back the Canadian vortex on the ECM outputs This trend is setting up a more prolonged colder pattern.

If we flick through the mean charts it is noticeable how the subsequent trough disruptions ease further west and and at a better angle to draw on that cold from further east.

http://www.wetterzentrale.de/pics/Reem481.gif

http://www.wetterzentrale.de/pics/Reem1681.gif

http://www.wetterzentrale.de/pics/Reem2161.gif

 

-5C uppers over much of the country by day 7 on the mean outputs.

 

Similar signs of the cold block becoming more influencial on the UKMO too.

 

http://www.wetterzentrale.de/pics/Rukm1441.gif

signs there that the next low is heading further west.

 

GFS op seems a little further north than it's own mean by day 6 onwards but still shows those Scandinavian heights ridging west

towards Iceland by day5 before the extra push from the Atlantic.

http://www.wetterzentrale.de/pics/Rtavn1201.png

 

So all in all further signs of the cold getting closer.

A while to go before confirmation but the very positive trend from yesterdays runs especially the ECM and UKMO continue today.

[Man With Beard]

LOL - let's wait until it's t48 before bringing up Feb 91. Right now I'd say only Northern areas are most certain for snowfall. 

 

It's a different kind of setup IMO, as right now we don't have the Scandi hook jet modelled (my own terminology! - where you get a loop running up over Scandi, down through Russia and a streak back round through the UK in a loop) - that helps bring the really deep cold from Russia around the high. Instead we have a more powerful SE jet - so it'll be harder to bring in the really deep cold, but it could still result in a lot of snow if we get lucky.

 

Here's the jet pattern from 1991

http://www.meteociel.fr/modeles/archives/archives.php?day=6&month=2&year=1991&hour=0&map=3&mode=0

 

 

The further North and East you are, the better if you're looking for snow, but if the very gradual retrogression of the pattern continues, then the snow zone will expand.

I'm just thinking, if the Atlantic can't knock the Scandi down having thrown the kitchen sink at it, any lull in the pattern/jet could mean it moves back west, and there's a massive great High stretching back to the Russia so a long-fetch easterly could follow ... yes agree with everything you write too but hey, part of the fun of this thread is speculating on what might happen! Hope the Daily Express doesn't quote me though