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Model output discussion - 16th Nov onwards


Paul

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

A fine selection of det. output from GFS and ECM this morning, in that the GFS 00z showed us what's possible if the trough disrupts substantially, the GFS 06z shows us what happens if it doesn't do so at all, and the ECM 00z is a blend of those two GFS efforts.

 

The fact that the GFS 06z still manages to bother the polar vortex with the Siberian/East Asian High enough to bring about a very ragged look by the run's end, with a potent northerly setting up for the UK as heights are able to rise to our NW from the Atlantic, is promising on the face of it. We can't rely on the model having the disruption process figured out though - I can recall many occasions in the past where it's been too fast with such processes, including in January this year, though the model was still in its 'parallel' state at the time so perhaps improvements have been made since then.

 

We do seem to have the potential for the blocking high to cause the stratospheric vortex to become tilted toward the UK as it builds down into the troposphere. That's an interesting variation on the classic El Nino picture, to say the least! 

 

 

Meanwhile, there's no mistaking the adjustments made by GEFS over the past few days, toward a more pronounced +AAM cycle during the next week, which is more like we'd expect to see with the El Nino background - though still a bit fast to leave phase 5/6 (stage 3 of the GSDM model; El Nino atmospheric state).

 

gfsgwo_1.png

 

Obviously any such adjustments beyond that range could change the tendencies shown for days 10-16 somewhat. Removing the -ve AAM cycle would be helpful for the wave breaking feedbacks, though really we need the AAM to climb back toward phases 5-6 for that to offer strong support. That venture into phase 1/2 (stage 1 of the GSDM; La Nina atmospheric state) is most irregular. A brief venture there followed by a return toward 5/6 could actually prove beneficial for messing with the polar vortex, but otherwise it's best to avoid 1/2 in the first place.

Edited by Singularity
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Posted
  • Location: Eastbourne and Larnaca,Cyprus .
  • Location: Eastbourne and Larnaca,Cyprus .

So once again a UKMO solution which progs something colder falls by the wayside.

 

In all my years on the net I can't remember it being a trend setter when it picks out the coldest solution during the winter months against the ECM/GFS.

 

Anyway back to todays longer range outputs, I'd be rather dubious of colder PM incursions at the longer range timeframes. Across all the models theres a bias to bring the colder air further south in this type of set-up, not helped by the fact that shortwave activity near Iceland is badly modelled at the longer range. The chance of PM incursions will increase if we see pressure rising near Svalbard as this will force low heights further se into Europe and help drive the colder air further south.

 

So for the timebeing more wet than white, any snow mainly reserved for higher hills and mountains. A very typical pattern at this time of year.

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

Jan or feb '13 nick

Disrupted the Atlantic trough and took the depression se at day 6. (Against all other modelling)

Really, I'm surprised, my memories not what it used to be!  Well done to the UKMO for being a trend setter once in nearly 3 years! lol

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Posted
  • Location: Exile from Argyll
  • Location: Exile from Argyll

Really, I'm surprised, my memories not what it used to be!  Well done to the UKMO for being a trend setter once in nearly 3 years! lol

I'm fairly sure it was right a few times in the past summer; bringing down the trough while the others were rushing to inflate the Euro high. Probably gone unnoticed as not under the same intense scrutiny here but not missed by the Scottish community who were always living in hope.

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Posted
  • Location: st albans
  • Location: st albans

Really, I'm surprised, my memories not what it used to be!  Well done to the UKMO for being a trend setter once in nearly 3 years! lol

The point being that it's very rare nowadays for a complete surprise solution to occur at day 6. It did happen many years ago but the improvement in the models over recent years would surely make this occurrence very unlikely now.

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Posted
  • Location: Kirkburton, Huddersfield - 162.5mtrs asl.
  • Weather Preferences: Winter synoptics.Hot summers.
  • Location: Kirkburton, Huddersfield - 162.5mtrs asl.

So who's correct

Met forecasting clear and cold overnight

EURO4 says otherwise

post-8269-0-41930800-1448121664_thumb.gi

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Posted
  • Location: leicester
  • Location: leicester

So who's correct

Met forecasting clear and cold overnight

EURO4 says otherwise

wasnt aware that there was a chance of snowfall across spine of england tonight!!up until this post no one has mentioned it!!
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Posted
  • Location: Kirkburton, Huddersfield - 162.5mtrs asl.
  • Weather Preferences: Winter synoptics.Hot summers.
  • Location: Kirkburton, Huddersfield - 162.5mtrs asl.

wasnt aware that there was a chance of snowfall across spine of england tonight!!up until this post no one has mentioned it!!

Precisely and moving south one would assume.Love weather don't you

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Posted
  • Location: Clayton-Le-Woods, Chorley 59m asl.
  • Weather Preferences: very cold frosty days, blizzards, very hot weather, floods, storms
  • Location: Clayton-Le-Woods, Chorley 59m asl.

Nice!!

 

h850t850eu.png

 

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h850t850eu.png

 

 

h850t850eu.png

 

h850t850eu.png

 

We could see widespread snow on this. Upgrade!! :) :)  :cold: :cold:

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

The low developing in the north sea could bring some pretty strong winds to the east if the air was cold enough we could be looking at some snow as well

 

gfs-0-192.png?12gfs-0-198.png?12gfs-0-204.png?12gfs-0-210.png?12

 

UKMO gives a days respite from the wind

 

UW120-21.GIF?21-17

 

Before we return to a westerly flow with the winds picking up again with the risk of gales in the far north

 

UW144-21.GIF?21-17

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Posted
  • Location: Rotherhithe, 5.8M ASL
  • Location: Rotherhithe, 5.8M ASL

wasnt aware that there was a chance of snowfall across spine of england tonight!!up until this post no one has mentioned it!!

On the latest GFS you can see a disturbance tracking south see circled I do not believe it was on the last run shows how dynamic it is!

post-19153-0-59999000-1448124626_thumb.j

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

Of course just as GFS really pumps up the Siberian high UKMO flips and comes up with a very progressive run - if we ignore it, will it go away?

 

GFS finishes on a very blocked note. Winter incoming if that were to verify.

 

gfsnh-0-384.png?12

Edited by Mucka
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Posted
  • Location: Clayton-Le-Woods, Chorley 59m asl.
  • Weather Preferences: very cold frosty days, blizzards, very hot weather, floods, storms
  • Location: Clayton-Le-Woods, Chorley 59m asl.

Whats interesting that is the high pressure is building over North Russia:

 

h500slp.png

 

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Extending bit further west across scandinavia:

 

 

h500slp.png

 

h500slp.png

 

Hints for possible blocking closer at home maybe?

Edited by pip22
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Posted
  • Location: Manchester
  • Weather Preferences: Sunny and warm in the Summer, cold and snowy in the winter, simples!
  • Location: Manchester

The gfs 12z is very ne blocked...bet we will see more over next few days...that sh high is causing the pv an the models serious headaches...good as it makes us model watchers fascinated by the possible outcomes...cold is on the agenda

 

 

Yes and a lot of that can be traced back to output that should be resolved very soon, the track of the low and how/if energy splits aiding/hindering Scandi ridge depending on how amplified things are behind.

 

First low, how much energy heads south aiding the ridge?

 

gfsnh-0-96.png?12

 

second low, how amplifed will the pattern be sending WAA to reinforce that ridge and disrupt the trough behind?

 

gfsnh-0-132.png?12

 

Because all this helps slow things down, back the pattern West and reinforce the Siberian high which in turn eventually may aid troughing into Europe and heights to be rebuilt toward Greenland. A lot of hurdles there and 15+ day pattern change :crazy:  but we will see.

 

Taking all that on board and looking at the GFS ensembles to the end of hi res, they are much better for phase 1 and 2 than the 06z(meaning better for blocking to our East/N East) so we will see if that translates to more blocked runs in deep FI.

 

 

A bit more in the sensible time-frame the GFS ensembles have been slowly firming up on another temporary cold shot around 27th/28th where the trough digs South (which is as a result of the Siberian highs influence so also a measure of that signal strengthening.)

 

GFS 12z short ensembles Central England.

 

graphe3_1000_250_80___.gif

Edited by Mucka
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Posted
  • Location: North East Cotswolds, 232m, 761feet ASL
  • Location: North East Cotswolds, 232m, 761feet ASL

I wonder what the latest EC32 is showing, be interesting to know if the SH is showing on that. We are also coming into the zone where the METOs long range is covering the Xmas period, fingers crossed for some blocking signals.

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

Curious how ECM keeps on developing a secondary low in the vicinity of Svalbard in 5-6 days time, yet GFS has refused to do so on the majority of its recent det. runs, the 06z of today being the exception.

 

It affects how close to our NE the Siberian/Asian high is able to move over the following few days. The GFS way forward has me screaming (okay, not literally) for trough disruption to occur around +216 - to no avail, of course. ECM actually manages to transfer the Svalbard low right across Siberia on this run which is a departure from its recent decision making but as it happens, the blocking high just builds back stronger behind it.

 

To quote from the better days of Kaiser Chiefs:

 

"Knock me down, I get right back up again, come back stronger than a powered up Pac-Man".

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Posted
  • Location: Camborne
  • Location: Camborne

The GEFS 6-10 tonight has HP Alaska, LP Greenland with associated trough orientated SE down through the UK as far as the Middle East and strong ridging over Russia. So a strong westerly component dragging systems east and dumping some wintry Pm air over the UK, particularly the north, so some quite squally periods. Any ducking and diving by the depressions will take them to the east down into central Europe courtesy of the upper trough.

 

The 11-15 still showing a familiar pattern to previous runs with a flatter pattern over North America, a weaker Greenland trough into Scandinavia and maintaining strong ridging over Russia. But there is also a suggestion of heights pushing up from south of the UK so although the zonal aspect of the streamlines is retained it is of Tm origin so more settled and temps maybe even slightly above average. At the moment there doesn't appear to be anything particularly odious lurking in the woodshed.

http://www.tropicaltidbits.com/

 

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post-12275-0-32923700-1448135889_thumb.p

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