Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Model output discussion - proper cold spell inbound?


Paul

Recommended Posts

Posted
  • Location: portsmouth uk
  • Weather Preferences: extremes
  • Location: portsmouth uk
49 minutes ago, Froze were the Days said:

CFS monthly runs not exactly picking up a cold/very cold signal either, March/April 2013 it was consistent with it's runs showing blocked conditions.

CFS monthly runs are about as useless as a 3 legged horse doing the grand national.

Anyway back to the real models and more realistic timeframe ECM has brought things forward each run for the last couple of days.

Consistent in my opinion.

ECM has modelled today very well 6am this morning 7c and now 3.3c sun shining with showers not far behind pretty cold northwesterly flow.

Snow for fair few especially west and Northwest some pushing well inland.

Very seasonal and pretty much likely leading to colder conditions as the vortex fragments and pushes jet and deep lows more and more on a southeasterly direction.

There will be milder interludes to but overall still heading in a good direction for the coldie crew.

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Bournemouth
  • Weather Preferences: Dry mild or snow winter. Hot and humid summer.
  • Location: Bournemouth
18 minutes ago, Summer Sun said:

Sure

ukm2.2018021600_168_lant.troplant_prp_fcst.gentracker.thumb.png.fadd93b85eab999d07337c4ea3721346.png

Many thanks. I would suggest more like ecm than gfs but a difficult call. The start of a ridge tho imo and less phasing as per nicks analysis.

Edited by That ECM
  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Bedfordshire/Herts border 40m asl
  • Weather Preferences: Cold, crisp, calm and sunny
  • Location: Bedfordshire/Herts border 40m asl

With such model uncertainty until the SSW outcomes begin to emerge I’m tempted to prescribe anti anxiety medication, therapy sessions and finally, circa mid next week, a nonbenzodiazepine hypnotic such as Zopiclone to aid desperately needed sleep, after each and every model run is pounced on, forensically scrutinised, over analysed and discussed in minute detail during the next three to five days.  Should the nw server crash in the meantime, meltdown referrals for inpatient care will go through the roof.... :help:  

Now, do I self prescribe or forceably limit myself to a once a day model watching-only brief? :unsure2:

Link to comment
Share on other sites

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

At least Google concur with the Ecm 00z run.:D:cold-emoji:

240_mslp850.png

240_mslp850uk.png

240_thickuk.png

doodle-snow-games-day-1-4597519198715904.2-l.png

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

So let's see... all 00z runs had Arctic height rises by day 5 but ECM and GFS keep a trail of low heights through Svalbard that prevents a linkup to the W. Asia height rises and leaves us waiting for the Atlantic zonal winds to tumble before we can get that continental flow set up (with only ECM delivering in this regard).

Given the forcing from above I would have though the models in general would be more keen to break down that trail of low heights but as it is, UKMO is the only one doing this within the next 5 days while GEM takes two days longer and the others even longer than that.

UN120-21.GIF?09-06 gemnh-0-168.png?00

 

I will admit that this reluctance is surprising me; I was anticipating a stronger, clearer model response to the first phase of warming that's focused a little NE of the UK. 

Obviously I have overestimated either the model's ability to handle the process prior to the SSW date (Sunday) or the SSW's ability to force strong blocking high development in the face of pre-existing troughs. Hopefully the former of the two as otherwise it's much harder to establish a long-fetch easterly that has the right alignment of flow to bring deep cold air from the likes of Siberia.

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

Posted
  • Location: East Ham, London
  • Location: East Ham, London

Morning all :)

On we go into February and with the vortex split now imminent and a possible SSW beyond that, more interesting chart watching ahead.

This morning I'm going as far as Monday February 19th.

Starting with ECM 00Z OP at T+240:

ECM1-240.GIF?09-12

Not a million miles away from yesterday's chart at this time and the rapid transition from a strong Atlantic to something much more blocked and amplified remains on course with this model. The Azores HP moves north than north east around the top of the British Isles and into Scandinavia opening the door to a cold ENE'ly flow. Wintry conditions for many especially in the south and east but cold and fine particularly in the north and west. The longevity of this pattern seems unclear at this stage.

GEM 00Z OP at the same time:

gem-0-234.png?00

After yesterday's little diversion, it's back to more of what we've come to expect from GEM with little sign of an E'ly or anything cold. The Atlantic has slowed but the Azores HP has ridged NE to the east of the British Isles to link with heights to the north of Scandinavia. On the western side of that ridge, a mild SW'ly flow crosses the British Isles so a taste of spring rather than winter for many especially in the south and east but more unsettled further west.

On then to GFS 00Z OP at the same time:

gfs-0-240.png

A classic winter chart with LP to the north and HP from the Azores ridging across southern Britain and Northern France. A mild SW'ly airflow with the driest weather to the south while the north remains more changeable with occasional rain or showers. Further into FI and the evolution becomes increasingly messy and quite hard to fathom as the Atlantic slows.

GFS 00Z Control at T+240:

gens-0-1-240.png

More dominated by LP than the OP but still an Atlantic-dominated chart. Control ends mild with rising heights to the south and the jet being pushed further north.

Looking at the GEFS at T+240:

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240

Plenty of solutions on offer but only 2-3 offering an easterly component at this time. There's a cluster which build the Azores HP north forming an MLB close to the British Isles but others show the Atlantic still trying to come through and with the Azores HP ridging at the same time we get a milder flow over the British isles than seemed the case yesterday.

That being said, by T+336, the number of GEFS with an E'ly component has increased markedly and more so by T+384.

In summary, the new acronym on this thread has been "QTR" for Quick Tropospheric Response. Some have shown we are likely to see that QTR from the vortex split and the Wave 2 attacks on the daughter vortices. Perhaps and ECM this morning supports that but neither GEM nor GFS convince and suggest we could be looking at 4-5 days further before we see a significant pattern change taking us into the last week of February.

I don't know - I do think proponents of QTR have taken a step back this morning and expecting the tropospheric response as early as T+240 from now seems unlikely but the wait may be worth it (or it may not). More runs are needed as always.

  • Like 6
Link to comment
Share on other sites

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

Never mind the SSW ... I can't believe we'll go another week without some decent snowfall if these extremely cold westerlies keep coming. GFS 06Z agrees (well it would, wouldn't it):

144-779UK.GIF?09-6  150-779UK.GIF?09-6  156-779UK.GIF?09-6

 

Edited by Man With Beard
  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Kings Norton, West Midlands
  • Weather Preferences: Thunderstorms, Cold & Snowy
  • Location: Kings Norton, West Midlands

Grizzly. All right, it isn't totally bad. Those in the West obviously favoured, but the vast proportion will miss out if we continue to have PM airmasses all Winter. 

gfs-0-192.png?6

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Inbhir Nis / Inverness - 636 ft asl
  • Weather Preferences: Freezing fog, frost, snow, sunshine.
  • Location: Inbhir Nis / Inverness - 636 ft asl

Much better heights over Greenland at just over a week away.

h500slp.png

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

gfsnh-0-216.png?6

Hmm okay but I want my giant blocking high advancing west from Asia back :nonono::laugh:

  • Like 1
Link to comment
Share on other sites

Much as I hate to say it, and looking at Stodges Input, 

18 minutes ago, stodge said:

Morning all :)

On we go into February and with the vortex split now imminent and a possible SSW beyond that, more interesting chart watching ahead.

This morning I'm going as far as Monday February 19th.

Starting with ECM 00Z OP at T+240:

ECM1-240.GIF?09-12

Not a million miles away from yesterday's chart at this time and the rapid transition from a strong Atlantic to something much more blocked and amplified remains on course with this model. The Azores HP moves north than north east around the top of the British Isles and into Scandinavia opening the door to a cold ENE'ly flow. Wintry conditions for many especially in the south and east but cold and fine particularly in the north and west. The longevity of this pattern seems unclear at this stage.

GEM 00Z OP at the same time:

gem-0-234.png?00

After yesterday's little diversion, it's back to more of what we've come to expect from GEM with little sign of an E'ly or anything cold. The Atlantic has slowed but the Azores HP has ridged NE to the east of the British Isles to link with heights to the north of Scandinavia. On the western side of that ridge, a mild SW'ly flow crosses the British Isles so a taste of spring rather than winter for many especially in the south and east but more unsettled further west.

On then to GFS 00Z OP at the same time:

gfs-0-240.png

A classic winter chart with LP to the north and HP from the Azores ridging across southern Britain and Northern France. A mild SW'ly airflow with the driest weather to the south while the north remains more changeable with occasional rain or showers. Further into FI and the evolution becomes increasingly messy and quite hard to fathom as the Atlantic slows.

GFS 00Z Control at T+240:

gens-0-1-240.png

More dominated by LP than the OP but still an Atlantic-dominated chart. Control ends mild with rising heights to the south and the jet being pushed further north.

Looking at the GEFS at T+240:

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240

Plenty of solutions on offer but only 2-3 offering an easterly component at this time. There's a cluster which build the Azores HP north forming an MLB close to the British Isles but others show the Atlantic still trying to come through and with the Azores HP ridging at the same time we get a milder flow over the British isles than seemed the case yesterday.

That being said, by T+336, the number of GEFS with an E'ly component has increased markedly and more so by T+384.

In summary, the new acronym on this thread has been "QTR" for Quick Tropospheric Response. Some have shown we are likely to see that QTR from the vortex split and the Wave 2 attacks on the daughter vortices. Perhaps and ECM this morning supports that but neither GEM nor GFS convince and suggest we could be looking at 4-5 days further before we see a significant pattern change taking us into the last week of February.

I don't know - I do think proponents of QTR have taken a step back this morning and expecting the tropospheric response as early as T+240 from now seems unlikely but the wait may be worth it (or it may not). More runs are needed as always.

From my novices' perspective the unwillingness of the PV lobe over Canada to move and the GEM and GFS favouring a continuation of the Atlantic lows does seem to me to be the most likely outcome. 

 

Link to comment
Share on other sites

Posted
  • Location: uxbridge middlesex(- also Bampton oxfordshire
  • Weather Preferences: blizzard conditions. ice days
  • Location: uxbridge middlesex(- also Bampton oxfordshire
22 minutes ago, Man With Beard said:

Never mind the SSW ... I can't believe we'll go another week without some decent snowfall if these extremely cold westerlies keep coming. GFS 06Z agrees (well it would, wouldn't it):

144-779UK.GIF?09-6  150-779UK.GIF?09-6  156-779UK.GIF?09-6

 

Its been 'notable' to say the least ...

People getting so hung-up on latter progression ie- ssw etc..they have been 'somewhat' blinded for near/medium term prospects.

The possibilities for the next few days are endless...and look to be fruitfull for many.

  • Like 3
Link to comment
Share on other sites

Posted
  • Location: Cambridge, UK
  • Weather Preferences: Summer > Spring > Winter > Autumn :-)
  • Location: Cambridge, UK

Well the 6z GFS is another epic fail and just keeps things mainly zonal and unsettled. Let's hope the ECM is on the right track.

Link to comment
Share on other sites

Posted
  • Location: Windsor
  • Weather Preferences: Snow and cold
  • Location: Windsor

Complete turn around from the GFS output this morning for the worse. Just hoping it’s latched onto a signal incorrectly otherwise it would be more of the same for the foreseeable.

Edited by prolongedSnowLover
  • Like 1
Link to comment
Share on other sites

Posted
  • Location: DL
  • Location: DL
2 minutes ago, tight isobar said:

Its been 'notable' to say the least ...

People getting so hung-up on latter progression ie- ssw etc..they have been 'somewhat' blinded for near/medium term prospects.

The possibilities for the next few days are endless...and look to be fruitfull for many.

These scenarios will bring unpleasant conditions for most of us... wet snow, ice a.m..  Nice to watch, not so nice to walk in.  (Unless you live above about 100m).  I'd rather have an early spring than cold zonal.

Link to comment
Share on other sites

Posted
  • Location: Manchester
  • Location: Manchester

More grim charts this morning- will the cold, wet weather from PM air masses ever end? I generally stay off here during winter but I would love some proper dry cold off the continent which has been so rare this winter so far, as opposed to this constant Atlantic muck.

There really has been an incredible amount of heavy, cold rain which I don't recall happening to this extent before in previous winters. Surely very few of us benefit or have a desire for these sort of conditions? 

Maybe someone else can enlighten me on this as I don't really study the charts during winter, but I don't get where all the energy is coming from for all these cold storms- they seem to be originating from very far north as opposed to the usual origin of our storms further south in the Atlantic.

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Cambridge, UK
  • Weather Preferences: Summer > Spring > Winter > Autumn :-)
  • Location: Cambridge, UK
2 minutes ago, Scorcher said:

More grim charts this morning- will the cold, wet weather from PM air masses ever end? I generally stay off here during winter but I would love some proper dry cold off the continent which has been so rare this winter so far, as opposed to this constant Atlantic muck.

There really has been an incredible amount of heavy, cold rain which I don't recall happening to this extent before in previous winters. Surely very few of us benefit or have a desire for these sort of conditions? 

Maybe someone else can enlighten me on this as I don't really study the charts during winter, but I don't get where all the energy is coming from for all these cold storms- they seem to be originating from very far north as opposed to the usual origin of our storms further south in the Atlantic.

Here is your culprit...

gfsnh-0-6.png?6?6gfsnh-1-6.png?6?6gfsnh-5-6.png?6

There has been a pool of very cold air stuck over NE Canada for ages...850s down to -40! This pours off the eastern seaboard, meets milder air from the south, tightens the thermal gradient, fires up the jet, and we are left with cold NW'erlies. Rinse and repeat.

  • Like 1
  • Thanks 3
Link to comment
Share on other sites

Posted
  • Location: uxbridge middlesex(- also Bampton oxfordshire
  • Weather Preferences: blizzard conditions. ice days
  • Location: uxbridge middlesex(- also Bampton oxfordshire
1 minute ago, prolongedSnowLover said:

Complete turn around from the GFS output this morning for the worse. just hoping it’s latched into a signal incorrectly otherwise it would be more of the same for the foreseeable.

Very likely (gfs)..picks signals then toys!.

Has an'overwellming, data point for decipher...and then leads when signal-data are mixed out.

Great model -but bipolar in diagnostics.

It has a keen relationship with warm sectors and Atlantic favour.

As well as late term blocking scenarios.

Medium term ens.. are better looked at atm..as a guidance with gfs!!!

Link to comment
Share on other sites

Posted
  • Location: Hertfordshire
  • Weather Preferences: SNOW AND FREEZING TEMPS
  • Location: Hertfordshire

To be honest the GFS 6z did move towards the ECM at day 9ish and then it just went off on one . Why is it always such a drama ? What I find odd is there's now HLB any where on that run . Why is that ??? 

Link to comment
Share on other sites

Posted
  • Location: Hull
  • Weather Preferences: Cold Snowy Winters, Hot Thundery Summers
  • Location: Hull
8 minutes ago, mb018538 said:

Here is your culprit...

gfsnh-0-6.png?6?6gfsnh-1-6.png?6?6gfsnh-5-6.png?6

There has been a pool of very cold air stuck over NE Canada for ages...850s down to -40! This pours off the eastern seaboard, meets milder air from the south, tightens the thermal gradient, fires up the jet, and we are left with cold NW'erlies. Rinse and repeat.

Yup you have hit the mark here. That cold pool over NE Canada is trouble for us as it fires up the jet. As the cold air outbreaks from this region interact with the well above average SSTs off the eastern Seaboard, this encourages rapid deepening of low pressure systems.

Strangely, the NE of Canada is one of the most likely places to be impacted by the SSW. Is the impact of the SSW slow to filter through? (chiono may be able to answer this - from what I have read an SSW can take a few days to a few weeks to filter through) or is another signal overriding it and keeping the polar vortex camped there?. Who knows? but I'd more favour the ECM as the GFS 06z goes against what would be expected.

Edited by Quicksilver1989
  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Hernia Bay
  • Weather Preferences: Heavy Snow
  • Location: Hernia Bay
5 minutes ago, ICE COLD said:

To be honest the GFS 6z did move towards the ECM at day 9ish and then it just went off on one . Why is it always such a drama ? What I find odd is there's now HLB any where on that run . Why is that ??? 

I would hazard a guess and say gfs is still finding its feet sorry be so ambiguous just a gut feeling 

Edited by snowfish1
  • Like 1
Link to comment
Share on other sites

Posted
  • Location: uxbridge middlesex(- also Bampton oxfordshire
  • Weather Preferences: blizzard conditions. ice days
  • Location: uxbridge middlesex(- also Bampton oxfordshire
5 minutes ago, Quicksilver1989 said:

Yup you have hit the mark here. That cold pool over NE Canada is trouble for us as it fires up the jet. As the cold air outbreaks from this region interact with the well above average SSTs off the eastern Seaboard, this encourages rapid deepening of low pressure systems.

Strangely, the NE of Canada is one of the most likely places to be impacted by the SSW. Is the impact of the SSW slow to filter through or is another signal overriding it and keeping the polar vortex camped there. Who knows? but I'd more favour the ECM as the GFS 06z goes against what would be expected.

Also gfs has inpartial data @this region-top canadian placings...and alaskan region!..

I'll try to bore you with facts stats- on this when i get a min!!!

And of the 4-suites thats moreso..than others!!..6z-12z-18z-00z

Edited by tight isobar
Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
  • UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-29 07:13:16 Valid: 29/03/2024 0600 - 30/03/2024 0600 THUNDERSTORM WATCH - FRI 29 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather

    Difficult travel conditions as the Easter break begins

    Low Nelson is throwing wind and rain at the UK before it impacts mainland Spain at Easter. Wild condtions in the English Channel, and more rain and lightning here on Thursday. Read the full update here

    Netweather forecasts
    Netweather forecasts
    Latest weather updates from Netweather

    UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-28 09:16:06 Valid: 28/03/2024 0800 - 29/03/2024 0600 SEVERE THUNDERSTORM WATCH - THURS 28 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather
×
×
  • Create New...