Model Output Discussions 18z 31/01/2016

[shane303]

I think the main concern at this moment is the possible damaging winds on Sunday / Monday in the south. The cold is not important at the moment. 

[BLAST FROM THE PAST]

4 hours ago, Fozfoster said:

Hi BFTP, this winter it always seems to be 9-10 days away!!

I should have said and agree that ECM is a reasonable run throughout but looks very interesting days 8+.  The problem is we have a nice runner come Sat/Sun but the resident trough to our north prevents real cold air being in place thus its almost a wasted runner just being wet and very windy.  Very much an issue for this segment of the NH

 

With the potential volatility coming our way we cannot pinpoint a particular run though, but stormy for sure and I think we'll be getting many more weather warnings ahead.

I agree with Gibby's round up

That was to save reposting it but it's got splashed all over this page now anyway. 

 

BFTP

Edited February 2, 2016 by BLAST FROM THE PAST

[Gibby]

Just an observation but all this talk and seeking cold misses the potential severity of the weather that lies ahead. While the models all point to a period of damaging winds and heavy rain it hardly gets a mention here lost within the tedious hunt for a flake of snow. It's model output discussion and every weather type should be discussed in equal measure. This is the UK and cold is and always has been relatively rare even in Winter and with such a powerful Jet Stream at the moment some very interesting storm systems that could cause major disruption late in the weekend and early next week should mean there be more important things to discuss rather than snow. If these major storm systems are still shown in a couple of days expect early warnings to be issued and certainly not just for the North.

Edited February 2, 2016 by Gibby

[stodge]

21 minutes ago, Gibby said:

Just an observation but all this talk and seeking cold misses the potential severity of the weather that lies ahead. While the models all point to a period of damaging winds and heavy rain it hardly gets a mention here lost within the tedious hunt for a flake of snow. It's model output discussion and every weather type should be discussed in equal measure. This is the UK and cold is and always has been relatively rare even in Winter and with such a powerful Jet Stream at the moment some very interesting storm systems that could cause major disruption late in the weekend and early next week should mean there be more important things to discuss rather than snow. If these major storm systems are still shown in a couple of days expect early warnings to be issued and certainly not just for the North.

Very true, Martin. There still seems to be a lot of uncertainty over the weekend's storms and their exact track.

GFS 06Z Op output for Sunday showing perhaps the worst of the immediate conditions for the usual suspects (central belt of Scotland) but plenty of time for that to change and for secondary features to develop further south.

As we are where we are, it would be remiss of me to point out there were once again a lot of cold options among the GFS 00Z members this morning and a number showing the PV shredded or sent off to Hudson Bay so there's a lot going on up there at present  with any number of possibilities (including west-based negative NAO) on the table as we move toward the middle of the month.

[shane303]

With the jet stream heading south the severe gales/ storm risk comes with it not looking good especially Saturday onwards some named storms likely and affecting an higher amount of the U.K. Population. 

[Nick F]

Does look to turn rather windy again from Friday and over the weekend, as we see a 'parent' depression deepen underneath Iceland with secondary waves running NE across or north of the UK beneath - where these secondary features track is not too certain yet this far off, but Sunday looks earmarked for widespread gales or severe gales across the UK, with 60mph+ gusts indicated by 06z GFS in the south, higher in the north and west. Looks quite snowy across Scotland on Sunday too:

After the weekend, a colder W to WNW flow indicated Monday, then the next deep low arrives on a more southerly track for Tues/Weds, indicative of the jet stream diving further south. 06z GFS takes the low south of the UK - bringing gales to W and SW France. This is quite a big jolt south of the jet and Atlantic depressions moving in next week from the 00z and more akin to the ECM, which brings a low in across the UK next Tuesday, though not as far south as GFS. So tendency for Pm air dominating a lot more next week, but still the threat of gales or severe gales as the jet remains very active.

The 00z ECM ans 06z GFS bringing a more southerly tracking jet next week, with lows on a more southerly track as a result, cross polar ridging between west Canadian and Kara highs perhaps forcing the jet to track further south this side of the NH. Though still never getting cold enough for snow away from higher ground in the north and west.

By day 9-10, there are hints from the EPS mean of ridging in the Atlantic while troughing digs deep over Europe, though it may not last, as the extended EPS mean joins low heights spreading out of N America with the deep trough anomaly across the UK.

So all-in-all, more seasonal/average temps, cold at times in the north with hill snow, but also very windy and wet at times. No signs of any prolonged pressure rises in the Atlantic yet and certainly no signs of a big pattern change - albeit less mild signal next week. Think we may have to wait another week to see whether the MJO and strat may or may not start to shift or change the wave patterns to a more colder/blocked evolution to end Feb.

 

Edited February 2, 2016 by Nick F

[Frosty.]

The Gfs 6z shows more polar maritime influence next week as the jet takes a more southerly track so polar air increasingly into the mix, especially further north and there is a chance of snow at times and not exclusively for upland areas. There are also some calmer interludes with night frosts but also some very stormy spells...No towel being thrown from me yet!

[fergieweather]

1 hour ago, Gibby said:

Just an observation but all this talk and seeking cold misses the potential severity of the weather that lies ahead. While the models all point to a period of damaging winds and heavy rain it hardly gets a mention here lost within the tedious hunt for a flake of snow. It's model output discussion and every weather type should be discussed in equal measure. This is the UK and cold is and always has been relatively rare even in Winter and with such a powerful Jet Stream at the moment some very interesting storm systems that could cause major disruption late in the weekend and early next week should mean there be more important things to discuss rather than snow. 

Totally agree (the same 'snow-or-nothing' myopia was evident in winter '13-14, which - for 'neutrals' on the forum - was so noteworthy and fascinating as we sat under an unprecedented, relentless train of spectacular storms). I've personally found this winter equally compelling and unique.

Some bothersome-looking EC-ENS solutions are emerging more for southern areas into next week through to mid-month. 'Cold' issues are quite evidently a mere sideline in terms of current medium range model interest. It's going to be a very interesting period (for those with broad weather fascination) with potential for some decidedly volatile conditions. 

[MP-R]

1 hour ago, Gibby said:

Just an observation but all this talk and seeking cold misses the potential severity of the weather that lies ahead. While the models all point to a period of damaging winds and heavy rain it hardly gets a mention here lost within the tedious hunt for a flake of snow. It's model output discussion and every weather type should be discussed in equal measure. This is the UK and cold is and always has been relatively rare even in Winter and with such a powerful Jet Stream at the moment some very interesting storm systems that could cause major disruption late in the weekend and early next week should mean there be more important things to discuss rather than snow. If these major storm systems are still shown in a couple of days expect early warnings to be issued and certainly not just for the North.

With the greatest respect, Gibby, and I do greatly value your posts, I think an equal number of people on here are now simply interested in something dry/warmer as well as cold. Yes, of course, the current models are still showing severe weather, especially given the time of year, but the fact is a large proportion of us aren't balled over by wind and rain, however severe. This weather is hardly of interest anymore having been going strong since late October and is irritatingly repetitive. Hence, people will find anything other than that in the models to discuss as if we just keep posting charts showing raging zonality, this thread becomes incredibly boring.

That aside, GFS 06Z shows an evolution regarding that low on 09th//10th, that would favour snow on the northern/western flank if only there were cold enough uppers to tap into. I'm amazed how little cold air is around at the moment. The -5 isotherm only offers a 'blink and miss it' passing to the southern UK, with the +5 isotherm covering the whole UK without a problem on the 16th (FI granted). I much prefer the latter slides of the ECM 00Z showing a general slowing of the jet after the 10th, with more cold air in place and more opportunities for dry/sunshine beyond. Before that, a pretty horrid weekend to come from a wind point of view. Not sure on precipitation levels yet - yesterday, although windy, was bone dry down here!

[ukpaul]

I, for one, am concerned about these storms given their effect on me as well as others. The one I am most concerned about is this, as below. Being overnight I doubt I'll be able to sleep, with added noise and vibration. 2013-14 was the absolute nadir, I managed to travel away from some of the worst of it over Christmas but spare a thought for those who are 'trapped'!

This, for example. I'd even endure 30 degree heat for a week than have this again.

Edited February 2, 2016 by ukpaul
Map wasn't visible

[BLAST FROM THE PAST]

Nice to see Fergie using 'volatile' as well. nothing else to describe  it better really.

I'm going to use a blend of 2 runs here to show that it's still too difficult to define detail yet.

00z

now if we go that with trough to NNE aligned better to bring colder air furthe south and more widely than 06z at that point and then had a runner like 06z

 

Could get more interesting.  It's fascinating to see that we still aren't getting enough cold air to flood down to produce a 'general' snow event.  It seems that westward bulge near Iceland is preventing and modifying any northerly shot.

 

BFTP

 

Edited February 2, 2016 by BLAST FROM THE PAST

[Man With Beard]

GEFS Northern Hemisphere profile: some blocking in N Atlantic, but all members retain strong vortex over Canada, so a chance of a temporary block but not likely to last long

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=240

ECM ensembles London: if anything, they are back on an upward trend for temperatures - very few runs that could be described in the "cold category" even out to D15

At present, what we can see suggests colder spells limited to 24/48 hour affairs at most.

Fence panels, however, are not so safe - a number of ECM members at T120 with gales or better, in various locations:

 

 

[Singularity]

Yes, while we wait to see if the sliding lows can do anything useful mid-month from a snow perspective, there is plenty of active weather to keep track of!

The first significant threat for the south comes along Saturday or overnight into Sunday, in the form of a secondary low that ECM turns into a nasty looking feature (below-left), but with GFS not so interested, the 00z shown below-right (and the 06z has an even shallower feature):

  

Intriguingly, GFS produces a narrow band of 50-60 mph gusts on both its 00z and 06z runs, suggesting a very active frontal boundary regardless of just how much the secondary low develops, perhaps featuring a potent squall line or two.

ECM separates the secondary low from the parent low more, allowing for more independent development and further south, which places a seriously tight pressure gradient across the far south. Enough for a short spell of 70 mph gusts even inland, with 80 mph not out of the question where particularly exposed.

UKMO, meanwhile, tracks the feature yet farther south and would probably bring more of a heavy rain threat to the south (rain band pivoting, countering eastward movement for a time, prolonging the rain) with strong winds hitting France instead.

 

With this range of options, it seems at least a brief spell of winds strong enough to bring a few branches down is likely but by no means certain, with a near equal chance that these winds could miss to the south or turn out to be stronger and hence capable of causing structural damage. 

GEFS cluster analysis supports this analysis, with 60% similar to the 00z or 06z det. runs, 25% more like ECM, and 15% more like UKMO.

 

Following this relatively focused event comes a far more widespread event, from a deep storm tracking further south than we've been seeing for much of this winter, and more importantly looking to develop a secondary feature along the base which threatens to bring some very strong winds somewhere across the southern half of the UK for a time.

 

  

Comparing the 00z output from big three (ECM, GFS then UKMO), we can see that ECM tracks the core of the low further south than GFS, but GFS develops more of a secondary feature on the south side. ECM has the core pressure at 952 mb just prior to reaching the UK while GFS was at 960 mb for the low at that position. Peak winds could be pretty similar for both scenarios, this being 60-70 mph widely inland with 80 mph or so affecting the coasts. UKMO has the storm at both a similar position and intensity (955 mb core) to ECM for that same moment in time, which is quite the coincidence!

However, at this sort of range, although the general theme will be well sorted, notable timing differences can be expected from run to run. Case in point, the GFS 06z has turned out to be a fair bit faster with the low, similar in intensity to the 00z but with less of a secondary low. This limits peak inland winds to around 60 mph for example. The intensity is still open to some question as the exact position of the storm relative to the near 200 mph jet stream is important.

 

 

Looking still further ahead, and the idea of a cut-off low has lost some favour this morning. Instead we have more of a sliding low but again with an unusual lack of trough disruption, resulting in type of 'bowling ball on a ramp' low that can bring prolonged heavy rain to a large part of the country. GFS produces 20-30 mm widely which is notable given how poorly it captures convective elements - these being an increasingly significant component at this time of year, as the sun gains some strength.

I daresay ECM's version would be nasty across much of England and Wales, as the low deeper than GFS has it, and rife with secondary features that tighten the pressure gradient and increase rainfall amounts. 

 

We have drawn so many short straws from the pot of late, surely there can only be long ones left? 

[Frosty.]

I'm actually quite encouraged about next week and beyond because according to the experts it looks like temperatures will begin to fall a little, meaning an increased risk of seeing night frosts and also more in the way of snow, especially across high ground and more generally in the north which sounds like a blend of what all the major op runs and ensembles are showing...so, it could become more wintry next week than some think, at least for the north and towards the end of next week and into the following week we could have a settled spell with frost and fog. As a cold / snow starved coldie, it doesn't look like we will go back to the nadir we experienced in December!

Edited February 2, 2016 by Frosty.

[SLEETY]

no sign of anything wintery for most uk ,just stormy it seems ,

[fat chad]

1 hour ago, ukpaul said:

I, for one, am concerned about these storms given their effect on me as well as others. The one I am most concerned about is this, as below. Being overnight I doubt I'll be able to sleep, with added noise and vibration. 2013-14 was the absolute nadir, I managed to travel away from some of the worst of it over Christmas but spare a thought for those who are 'trapped'!

This, for example. I'd even endure 30 degree heat for a week than have this again.

Given that this storm is 5 days away, what are the chances of this storm actually hitting the uk or otherwise hitting France instead.. ?

[snowray]

This looks Wintry, quite surprised to see that chart from the high res GFS for tomorrow morning. Upgrades!!

[Timmytour]

4 minutes ago, fat chad said:

Given that this storm is 5 days away, what are the chances of this storm actually hitting the uk or otherwise hitting France instead.. ?

Given that it concerns the weather that we don't really want and not the cold and snow so many of us do want......I'd say the chances are pretty high it hits us!

[shane303]

12 minutes ago, SLEETY said:

no sign of anything wintery for most uk ,just stormy it seems ,

No a downward trend in temperature so don't agree with no sign of wintry. Snow likely in the north and even further south at times in the next 14 days or so also some overnight frosts. 

Edited February 2, 2016 by shane303

[Jimmyh]

also bear in mind what has been said by Fergie that it is not all about the snow and ice hitting us as it is the permutation of the south being hit by one of these barrel storms. 2013/2014 was hell down here not had a storm so bad this winter but I know that we are due one.

 

All of the models are pointing towards a nasty spell of weather and it is now within the timeframe of it hitting

[Fozfoster]

http://earth.nullschool.net/#current/wind/isobaric/1000hPa/orthographic=-6.50,58.35,1216/loc=-1.460,51.932

This link shows you whats happening our side of the world plus far left is the next storm...

[ukpaul]

9 minutes ago, fat chad said:

Given that this storm is 5 days away, what are the chances of this storm actually hitting the uk or otherwise hitting France instead.. ?

Singularity gave it a good summary a few posts earlier, maybe 60% chance (at the moment), could be even windier as per ECM or equally sending it to France as per UKMO Nothing against the French but more rain but less wind would be my preferred outcome.

[pdiddy]

3 minutes ago, Jimmyh said:

also bear in mind what has been said by Fergie that it is not all about the snow and ice hitting us as it is the permutation of the south being hit by one of these barrel storms. 2013/2014 was hell down here not had a storm so bad this winter but I know that we are due one.

 

All of the models are pointing towards a nasty spell of weather and it is now within the timeframe of it hitting

There's a lot of IMBYism going on here... Central Scotland has had 80mph winds twice in the last week, but we should now get excited because it's the South?

Anyway, back on topic, jet sinks further South, models twitching about the SSW and the MetO talking of a colder spell mid-month.  Models also showing some more wet and windy weather to come...  Interesting model weatching indeed.

[Long haul to mild]

We get wind and rain pretty much all year round so while I agree there is some notable weather in the medium term, I use the models to look for something different. 

Therefore my focus will remain on the hope of something either  involving cold and snow or some pleasant unseasonable warmth. Certainly no sign of the latter at present in the models but looking at the outputs today, it wouldn't take a lot to turn a UK trough to something that would open the floodgates to a Northerly. 

ECM and some GFS ensemble members have continually shown interest in something wintry as we go to mid month and a slight nudge in the right direction (East and South!) will pay dividends. 

[Mucka]

It would be nice if people didn't try to dictate what others post about within the model output thread. (Beyond mods doing their thing)

If you want to post about a particular aspect then do so (Gibby and others)  and I won't tell you what to post about in return. Personally I find wind and rain tedious as it is our staple diet in Winter but I am more than happy to read others views on it if it floats their boat.

Bottom line is different people get different things out of the weather and there is room for all, no need for gags or lashes.

On that note, no real sign of an end to the stormy mobile weather in the charts so far today so we are now looking to mid month for the trough to dig South into N Europe and ridging behind, Fergies update was very positive in that respect so although no end of the zonal train really in sight yet I am still hopefull we can see soemthing quieter and colder to see the Winter out.