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Model Output Discussion - 23rd Jan - 12z onwards


Paul

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Posted
  • Location: Dublin, ireland
  • Weather Preferences: Snow , thunderstorms and wind
  • Location: Dublin, ireland

What a vast improvement in the GFS ensembles from last Sunday compared to today.

 

 

post-2637-0-01322100-1422580654_thumb.pn

post-2637-0-27591200-1422580665_thumb.pn

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Posted
  • Location: Gillingham, Kent
  • Weather Preferences: Snow, Thunderstorms,
  • Location: Gillingham, Kent

Tonights ensembles remind me of 2010.. The swift in all ensembles for mild to cold happened more or less overnight.

 

We're looking at, at least 8 days of cold, probably likely to be extended further too

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Posted
  • Location: Maidstone ❄kent❄
  • Weather Preferences: Snow,Snow & Snow.
  • Location: Maidstone ❄kent❄

Models seem to be singing from the same hyme sheet this morning of a break down in the cold theme towards the end 

of next week. Its all right rolling out the JMA models etc but when do they ever verify, hardly ever.

Good morning,

When u say a breakdown do you mean the Atlantic coming in or high pressure moving in and cutting of the northerly ?

Many thanks.

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Posted
  • Location: Crayford/Baker Street By Day
  • Location: Crayford/Baker Street By Day

Ok first technical post from me just had a look at the ensembles and they are solidly below -5 right the way through till Friday of next week 850's so why people call the end at 160+ of this cold spell is beyond me

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

The models are all singing from the same hymn sheet, they are all showing a very cold week ahead with widespread moderate / severe frosts and increasing amounts of snow showers around the coasts and perhaps further inland at times, also a threat of more persistent wintry ppn into the west /sw early next week.

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Posted
  • Location: Drayton, Portsmouth
  • Location: Drayton, Portsmouth

Well, Polar Vortex seems to have predicted the ECM to be fair to him, not sure how you can do that an hour early though!

Proper milder air trying to break through at T216 as the Euro trough collapses somewhat. It's not an unreasonable option for where this is going but it seems a bit progressive compared to the ens from last night.

In all honesty though, really not much point looking beyond T168, FI is always nearer in a UK cold spell.

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Posted
  • Location: st albans
  • Location: st albans

Hi,

 

This may have been asked before but I cannot find the answer on the learning part of the forum:

 

What is the difference between the control run and the operational run and which is the most accurate , if either may be the case?

 

I do understand the concept of the ensembels and the different perturbations etc.

John - the gefs control is running at a lower resolution than the op (much lower now) but with the same starting data. It runs at the same resolution out to the end of the run. The other gefs ens become lower res at T192.

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Posted
  • Location: Weymouth, Dorset
  • Location: Weymouth, Dorset

Models seem to be singing from the same hyme sheet this morning of a break down in the cold theme towards the end 

of next week. Its all right rolling out the JMA models etc but when do they ever verify, hardly ever.

It's only you singing from your own hymn sheet I'm afraid. The name sort of gives it all away anyways...

A 'heading milder' option at D10+ on the model output is always going to be there in any cold spell, even if it transpires I suspect it will be more transient than a pattern change, the best is yet to come.

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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

Morning all

 

On the face of it a breakdown in the cold looks to be arriving by  next weekend however if we had also believed output a few days ago the breakdown would have been occurring by Tuesday so I think we need to wait and see if this is modelled within the T144hrs timeframe.

 

The overnight runs do diverge somewhat in terms of flow into the UK, the UKMO is least interested about drawing in a more ne flow, the ECM does bring that in for a few days and this is of course will be of interest for those towards the east and se, the GFS also supports this.

 

The reason I'd urge some caution re the outlook is once again the conflicting signals regarding the MJO, the GEFS has this moving into a decent amplitude phase 7 then 8, the bias corrected into phase 7 then towards the COD, the ECM scrapes this into phase 7 but has low amplitude.

 

On recent history the actual result has been a blend of the GEFS and GEFS BC so I think we need to wait to see if theres a convergence across the model suite.

Edited by nick sussex
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Posted
  • Location: Wellseborne, Warwickshire
  • Weather Preferences: Southerly tracking low pressure in winter. Hot and thundery in the summer
  • Location: Wellseborne, Warwickshire

Forgive me for not posting charts my iPad is up the duff at the minute . But if you have a look at the ecm at t96 , we have a good northerly , a very strong atlanitc block , then jump to t120 and we have it seemingly pushed aside with low pressure ridgging over the top , it just doesn't look feeseble to me . It's the most progressive model to do this , I don't no where we'r heading , I thought we would see a move to a Scandi high this morning tbh , but it's not really evolved . Yes we get a slack easterly of sorts on the gfs especially but not what I had in mind . But hey ho , I don't really think anyone can say where the breakdown is gonna come from . If at all .

Really think we'r gonna see an easterly by mid February .

As re the polar low I had heavy sleet . After heavy snow showers all eve its washed the snow away . Some polar low ! The lesson : if the met isn't raving about it , then it's not gonna happen .

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Posted
  • Location: Peterborough
  • Weather Preferences: Snow and frost in the winter. Hot and sunny, thunderstorms in the summer.
  • Location: Peterborough

The operationals are certainly not as positive as last night, but the net result still stands that the keep a cold or very cold feed until around next Friday instead of Wednesday which was the trend 24 hours or so back. The pattern tending to recycle the Atlantic ridge with a brief north easterly before toppling it again.

At this juncture I would still say a true easterly is more than possible. It's just the case that no model really goes with it this morning. 

GFS mean for Next Saturday

gens-21-1-192.png

Still cold for all with a north easterly feed across the south. So the GFS at least seeing this cold spell last throughout next week.

 

ECM ends the coldest weather on Friday, GEM is also Friday and the UKMO looks the flattest but its still Thursday and there is still a wind from the north which could bring scattered snow showers.

Edited by Captain shortwave
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Posted
  • Location: Epsom, Surrey, 100 Meters above sea level
  • Weather Preferences: Anything Extreme
  • Location: Epsom, Surrey, 100 Meters above sea level

A thought has occurred to me this morning, something which I have been thinking for a time, but really didn't want to accept. 

 

But, given how things are shaping up, many of us could very well go through this entire cold spell without seeing anything falling from the sky that is white, the charts look cold yes, but the consistent theme is that they are also looking dry. 

 

I'll be really gutted if we get to the end of this cold spell and don't see any snow, that would be a harder pill to swallow than not having the cold at all. 

 

The UKMO at + 144 doesn't look great to me , OK it's not mild, but it's as dry as a bone, the Easterly being shown by the ECM is too slack for any PPN and it's all too brief an affair. 

 

UW144-21.GIF?30-06

Indeed further North there is no easterly feed at all on the ECM

ECM1-168.GIF?30-12

 

The 18z GFS Ensembles were pure heaven, I've not yet seen the 00z , but looking at the OP it's not really giving much thought to an Easterly setting up shop either. 

 

gfs-0-144.png?0

 

Don't get me wrong some people have had snow and that's great, we've all had the cold and that' great too, it's just I can see a lot of folks seeing naff all in the way of snow from this, if it pans out as the big 3 are showing, what use if having the cold if it aint gonna produce the goods. 

 

I hope we see a shift toward a more beefy Easterly in the coming days, or at least a reload from the North West to keep things interesting

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Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire

Just want to echo the thoughts of others this morning.

 

I distinctly remember a few days ago replying to WIB saying the cold spell looks to continue until at least the 4th Feb and now that date appears to be Feb 8/9th. At the moment next week looks more notable for hardfrosts rather than snowfall but the period between +96 & +144 could easily see this swing towards a colder, more wintry E,ly.

 

Sorry my post is brief but last night's fun and games have worn me out.

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Posted
  • Location: Bournemouth
  • Weather Preferences: Dry mild or snow winter. Hot and humid summer.
  • Location: Bournemouth

Met office hinting at breakdown next weekend.

http://images.meteociel.fr/im/7859/ECH1-240_bki1.GIF

Output suggesting this possibility, yet when someone suggests it they often get shouted down...

If this were the other way round, not many would have a problem with people hunting for cold....

A little respect to others opinions and each other would be a good discussion I feel.

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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

Forgive me for not posting charts my iPad is up the duff at the minute . But if you have a look at the ecm at t96 , we have a good northerly , a very strong atlanitc block , then jump to t120 and we have it seemingly pushed aside with low pressure ridgging over the top , it just doesn't look feeseble to me . It's the most progressive model to do this , I don't no where we'r heading , I thought we would see a move to a Scandi high this morning tbh , but it's not really evolved . Yes we get a slack easterly of sorts on the gfs especially but not what I had in mind . But hey ho , I don't really think anyone can say where the breakdown is gonna come from . If at all .

Really think we'r gonna see an easterly by mid February .

As re the polar low I had heavy sleet . After heavy snow showers all eve its washed the snow away . Some polar low ! The lesson : if the met isn't raving about it , then it's not gonna happen .

The thing is the ECM and UKMO are pretty close at that timeframe, the issue going forward is really how the ridge topples and how far north this will be which will of course effect any cold on its southern flank.

 

The UKMO is pretty cold at T120hrs as a parcel of -10 850's finally get pulled se in to the UK. The current cold however is really not supportive of all snow events and that's my criticism of this spell so far, this northerly is not really a proper Arctic one yet as the sourcing is north of Norway and not a direct feed from the Arctic.

 

As northerlies go this gets 2 stars, to get towards 4 and 5 stars this needs to be in relation to proper blocking over Greenland. This northerly is really just a flow running anti clockwise round the Euro troughing. This might sound a bit picky but the current cold spell whilst delivering some snow and decent totals  to some locations fails the "crunchy snow" test!

Edited by nick sussex
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Posted
  • Location: Wellseborne, Warwickshire
  • Weather Preferences: Southerly tracking low pressure in winter. Hot and thundery in the summer
  • Location: Wellseborne, Warwickshire

The thing is the ECM and UKMO are pretty close at that timeframe, the issue going forward is really how the ridge topples and how far north this will be which will of course effect any cold on its southern flank.

The UKMO is pretty cold at T120hrs as a parcel of -10 850's finally get pulled se in to the UK. The current cold however is really not supportive of all snow events and that's my criticism of this spell so far, this northerly is not really a proper Arctic one yet as the sourcing is north of Norway and not a direct feed from the Arctic.

Agree in the main . This northerly is only really setting it from tomorrow and we can see kinks in the isobars on the models particulary on gfs , which surely would bring some snow South ? Early next week looks best for this . Monday and tue I would say . But the low dropping South on Sunday from Iceland doesn't really look like reaching land fall now so think the threat will recede in met forecast . Hope I'm wrong though ?

post-9095-0-93299000-1422605468_thumb.jp

Woooo iPad working !

Edited by Severe Siberian icy blast
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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

Agree in the main . This northerly is only really setting it from tomorrow and we can see kinks in the isobars on the models particulary on gfs , which surely would bring some snow South ? Early next week looks best for this . Monday and tue I would say . But the low dropping South on Sunday from Iceland doesn't really look like reaching land fall now so think the threat will recede in met forecast . Hope I'm wrong though ?

attachicon.gifimage.jpg

Woooo iPad working !

If you look at the precip associated with that shortwave its actually towards the sw and Ireland, its ironic really because if the pattern was less amplified that would go se not s/sw but then that would be a bellwether that the upstream pattern was flatter and hence less likely to develop ridging ne afterwards.

 

The latest ECM postage stamps are out, still a lot of variation at T120hrs in terms of potential for a colder easterly to develop.

 

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2015013000!!/

Edited by nick sussex
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Posted
  • Location: Reigate, Surrey 78m asl
  • Location: Reigate, Surrey 78m asl

The GFS ensembles keep us in the cold until at least 7th Feb - the op is towards the upper end at that stage... Many keep the cold uppers until the 9th at least and then there's much scatter - most off the milder options are likely high pressure?

post-686-0-26242500-1422606107_thumb.jpg

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Posted
  • Location: Wakefield, West Yorkshire
  • Location: Wakefield, West Yorkshire

Met office hinting at breakdown next weekend.

http://images.meteociel.fr/im/7859/ECH1-240_bki1.GIF

Output suggesting this possibility, yet when someone suggests it they often get shouted down...

If this were the other way round, not many would have a problem with people hunting for cold....

A little respect to others opinions and each other would be a good discussion I feel.

Totally agree. Someone yesterday said about the 18z and then waking up for the 0z that it's likes going to bed with a 10 and waking up with a 6. This morning is one of those days again.

Lots of ramping last night about upgrades and then we have this mornings disappointment. HOWEVER as the saying goes it's only one run (albeit with reasonable agreement).

Funnily enough I was watching Francis Wilson's Feb 1991 forecast on YouTube this morning - what I'd give for another forecast like that!

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Met office hinting at breakdown next weekend.

http://images.meteociel.fr/im/7859/ECH1-240_bki1.GIF

Output suggesting this possibility, yet when someone suggests it they often get shouted down...

If this were the other way round, not many would have a problem with people hunting for cold....

A little respect to others opinions and each other would be a good discussion I feel.

 

Yes, well said. Some are picking up on a potential breakdown, albeit the ens don't really agree.

 

I would try to focus on getting the cold in place first though, before looking for the end on charts 10 days away.

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