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Model output discussion 13th Feb onwards


Paul

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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

Just when you thought the worst was over, along comes the Gfs 00z op run with a swarm of angry looking atlantic depressions taking dead eye aim at the uk through early march. The week ahead looks very unsettled with further bouts of strong winds and heavy rain, early next week a low spills in off the atlantic and then remains in situ as a slowly filling feature before the next low sweeps in from the west and engulfs it's remains to reinforce the unsettled spell. Colder air does gradually seep south by the end of next week as a sliver of high pressure extends south from iceland which briefly cuts off the atlantic express with a dry and brighter period with widespread frosts but into next month the truce ends with the atlantic juggernaut blasting through once again, on the plus side of all this, it does look like a rather colder spell is on the way with a higher risk of snow, at least across northern hills, and an increasing incidence of overnight frost and ice during the quieter intervals.

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Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

The cool spell beginning to wander into UKMO field of view. Very good model agreement across all models on the general idea just a lack of proper cold uppers. When it gets closer if it doesn't disappear it will be worth checking with the will it snow guide to get a feel of what might happen.

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Posted
  • Location: st albans
  • Location: st albans

charts which appear to show wintry nirvana will often disappoint once we get to late feb and beyond. given the dearth of wintryness thus far, i suspect even wet snow would be welcome! The charts do look promising but at the moment but we dont have all the models showing the same depth of cold and we dont have inter run consistency. A long way to go yet and that doesnt allow for the fact that the current runs dont really show snowfall away from elevation.

The ecm ens for london showed only a handful of members finding a sub 4c max day over the next two weeks. More encouragingly, the mean precip now drops nearer 25mm and the gefs precip also looks more muted apart from a few days this upcoming week. the upcoming cold period upstream and resultant stronger atlantic jet is not modelled to pile trough the uk - the usa cold not digging as far south as previous spells and with a slacker thermal gradient means the jet streak not quite as strong as previous.

Roll on spring and some warm sunny days..........

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Posted
  • Location: Kilmersdon Radstock Somerset
  • Weather Preferences: None Really but a snow lover deep down
  • Location: Kilmersdon Radstock Somerset
Good morning. Here is the report on the midnight outputs from the big 5 this morning being Saturday February 22nd 2014 and taken from my website at http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm
 
All models show a developing and strengthening SW flow across the UK today and tomorrow. Troughs of Low pressure will move quickly NE across Scotland today with heavy rain with the trailing cold front meandering only slowly SE across the UK later today, tomorrow and into Monday with copious heavy rain totals over the hills of the North and West. Then on Monday the cold front scoots away east over England to be followed by another complex Low pressure area and fronts develivering further rain then showers across the UK in westerly winds by midweek. It will be mild in the South and East until Tuesday when average temperatures return for all.
 
GFS then shows midweek and the end of the week for that matter as very unsetteld with further rain and showers in cyclonic winds and average temperatures before things turn colder under a Northerly flow at the weekend with wintry showers towards the North and East and frosts at night generally. Through the remainder of the run changeable conditions persist but the weather will be much less wet than recently over the South in particular with the most frequent and heavy rainfall likely to the NW. With drier and finer weather in the South frost at night could be more common if skies stay clear.
 
UKMO closes its run with the end of next week with Low pressure over the North Sea with a showery WNW flow across the UK with most of the showers in the North and West where they will become wintry over the hills by the weekend.
 
GEM shows a colder and showery period next weekend with wintry showers almost anywhere but more especially over the north and East in NW or North winds allowing frosts to develop at night under increasingly clear skies at night by the end of the run.
 
NAVGEM introduces colder weather too by next weekend but it shows unsettled weather persisting with rain at times or indeed snow over the hills as it turns colder with frost at night likely.
 
ECM at last shows a drier spell developing from next weekend as an extension of the Azores High throws a strong ridge our way with any wintry showers fading ahead of dry and bright daytime conditions and frosts at night.
 
The ECM 9 and 10 Day Mean Charts indicate less support for the operational than one would of liked with the maintained link of low pressure from the NW down across Britain to Europe which would maintain an unsettled and somewhat cool feel to things over the UK. 
 
 
 
The GFS Ensembles indicate an improvement in conditions after next week especially across the South with the azores High exerting more influence over this part of the World with most of the rain from Atlantic systems likely across NW Britain through Week 2.
 
 
The Jet Stream supports an improvement longer term as at last the flow ridges strongly North over the Atlantic and up towards Iceland in Week 2 allowing the Azores High to play a bigger role in domination of the Southern North Atlantic and Western Europe.
 
 
In Summary the signs of improvement shown over the last few days from certain outputs is gaining some momentum this morning (although I would of preferred the ECM Ensembles to of been more supportive) as a break in the flow of Atlantic Low pressure areas begins next weekend. The better weather may be preceded by a colder period where some wintry showers are possible as winds switch Northerly ahead of the developing ridge. there is better evidence that the ridge may hold firm rather longer across Southern areas at least and finally dislodge the Jet stream from it's Southern aspect and take it further north towards it's more common position North of the UK keeping Atlantic low pressure well North and keeping rain bearing fronts influential more towards the NW than recently. Temperatures never look like getting very low and daytimes could feel quite springlike especially with the higher elevation of sun now and the much lighter winds likely as a result.
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Posted
  • Location: West Dorset
  • Weather Preferences: Warm summers, Snowy winters.
  • Location: West Dorset

A little bit into FI but a definitive sign from the ECM that probably our coldest air so far is coming early March.

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Posted
  • Location: West Sussex
  • Weather Preferences: Extreme cold & snow
  • Location: West Sussex

Just a reminder of what March can bring if things fall into place.

 

Last year for example...

 

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It couldn't happen again could it, nearly a year to the day? 

 

Tonights 18Z below...

 

Cold uppers approaching from the North East.

 

Oh well, we live in hope Posted Image

00z and as they used to say on Monty Python

 

"and now for something completely different"

 

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Looks like rain is going to be very low in the NE of Scotland over the next 2 weeks if the GFS ensemble is anything to go by

 

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Further south and more lengthy periods of dry weather look likely for England as well

 

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Decent agreement as well at this stage for something cooler to develop during early March

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

from my daily check on each of the 3 main anomaly charts this morning

 

Sat 22feb

Ec-gfs

Both show the atlantic ridge and +ve heights turning the flow n of west into the uk with the marked  trough into Europe on both-heights around the 540dm mark in the s of uk, in spite of the ridging effect, so on this run looking a coldish possibly rather unsettled spell less unsettled nearer the ridge w/sw uk

If noaa at 6-10 again follows  this evening with its pattern from yesterday and before then, in spite of some variations over the last few days then it will look a ‘done’ thing. If not then still uncertainty.

As to how long this colder interlude will last=as ever hard to predict, 4-6 days perhaps, starting in 4-6 days time?

both latest outputs below

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

do NOT expect surface detail to be clear from these charts, that is not what they are for. They are used to show what the upper air pattern is probably going to be 6+days from now, maybe in this case 4-6 days from now. The detail will slowly become apparent on the synoptic outputs from the 3 main centres. Do not expect to know if it will snow in your backyard more than 24 hours either whichever model you prefer to use. That is IF this works out as it currently seems probable it may do.

 

If the upper air pattern on the synoptic charts is very similar to what those above show then you can be fairly sure that in most instances the surface pattern should fit reasonably well with what the actual shows when it arrives. If they do not fit then forget that model run.

Edited by johnholmes
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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

Yes pretty good agreement of a cold upper trough digging south across the UK at the end of the week as shown in the operational this morning and from those anomaly forecasts.

http://www.meteociel.fr/modeles/ecmwf/runs/2014022200/ECM1-144.GIF?22-12

 

I am just wondering as that trough starts to warm out around day 10-shown here in the means-if at last the Azores High will build more noticeably towards the UK.?

http://www.meteociel.fr/modeles/ecmwf/runs/2014022200/EDH1-240.GIF?22-12

http://modeles.meteociel.fr/modeles/gens/run/gensnh-21-1-240.png?6

 

Later NAEfs indicating gradually rising pressure over the near continent.

http://modeles.meteociel.fr/modeles/gens/naefs/run/naefs-1-0-300.png?0

 

the Azores high still looking a little flat for widespread fair weather here and of course the mean picture would dilute any sharpness in the ridging.However this could be enough to bring some further improvement with longer drier intervals and brightness, especially further south,as we go in March.

Edited by phil nw.
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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

ECWMF has ridging from day 9 and 10, it's no March 2012 but we're getting to the time of year when the sun alone can force a durinal range.

 

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Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

Well the GFS 06oz starts banging the nails into the cool spell with the downgrade setting in. If it follows the normal trends this winter the cool spell will just end up with average temps  and the normal damp wet stuff. However after this weekend it's looking like we're entering a quieter spell with most of low's energy spent spinning fish rather than launching projectiles on land. So quietening down which has been the trend in the last couple of days overall.

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Posted
  • Location: Manchester
  • Weather Preferences: Sunny and warm in the Summer, cold and snowy in the winter, simples!
  • Location: Manchester

Looks like we are lining up for a brief Northerly toppler

 

Here comes winter in March - but don't blink or you will miss it!

 

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If we can get the pattern backed West and a stronger ridge things would be a little more interesting

Edited by Mucka
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Posted
  • Location: Cardiff/Reading Uni
  • Weather Preferences: Snow, Sun, Heat, Cold,T/storms via Spanish plumes *rare*
  • Location: Cardiff/Reading Uni

Finally!! Frosty, crisp and most of all dry  at the end of high res on the 12z!

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Edited by Panayiotis
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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Looks like we are lining up for a brief Northerly toppler

 

Here comes winter in March - but don't blink or you will miss it!

 

Posted Image

 

If we can get the pattern backed West and a stronger ridge things would be a little more interesting

 

Yep blink and you'll miss it with out doubt with high pressure starting to move in next weekend, bringing some clam weather with overnight frosts

 

Welcome back high pressure just in time for the start of spring

 

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Just what the doctor ordered for the flood hit communities

 

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Edited by Summer Sun
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Posted
  • Location: Cardiff/Reading Uni
  • Weather Preferences: Snow, Sun, Heat, Cold,T/storms via Spanish plumes *rare*
  • Location: Cardiff/Reading Uni

Nothing new here but the GEM is going for the colder option...

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Posted
  • Location: Wildwood, Stafford 104m asl
  • Weather Preferences: obviously snow!
  • Location: Wildwood, Stafford 104m asl

GFS finally corrected Monday's rain, could not believe last 10 runs had it stalling to the west, giving midlands a dry day, now matches the FAX chart and moves monday's rain east, giving a very wet morning away from the SE

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

ECM following on from its 00Z run with high pressure building later next weekend before that we get north to north westerly winds to start spring

 

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Then from Sunday pressure builds

 

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ECM ends on a settled note with pressure building nicely its nice to see high pressure appearing just in time for Spring with some very welcome settled weather for all those affected by flooding this winter

 

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Edited by Summer Sun
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Posted
  • Location: Wildwood, Stafford 104m asl
  • Weather Preferences: obviously snow!
  • Location: Wildwood, Stafford 104m asl

Yeah a novelty, GFS on board so could well happen, HP to be in charge 02 Mar, unusual setup, last time a high close was 01 Dec, low pressure is boring

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Posted
  • Location: Coastal West Sussex
  • Weather Preferences: Hot Humid & stormy
  • Location: Coastal West Sussex

ECM following on from its 00Z run with high pressure building later next weekend before that we get north to north westerly winds to start spring

 

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Then from Sunday pressure builds

 

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ECM ends on a settled note with pressure building nicely its nice to see high pressure appearing just in time for Spring with some very welcome settled weather for all those affected by flooding this winter

 

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would that mean mild or cold ? nice sunshine and dry just what we need

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Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

Okay I'm not getting excited about FI as divergence  between the models is now setting in. Any cool spell note cool not cold is now looking a little bit iffy. GFS worst in levels of performance coming in normally no.3 does actually bring cold uppers in. None of the others follow this idea.

I got the feeling in the next few runs we end up again with more mobile wnw flow across the uk without any real cold uppers and just average temps for the year.

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

would that mean mild or cold ? nice sunshine and dry just what we need

 

Most likely it would be cold to start with before gradually turning milder towards the end though given it would be early March in any sunshine it should feel fairly pleasant

 

But most importantly it should become drier for all areas which can only be a good thing after the wettest winter on record for some

Edited by Summer Sun
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