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Model Output Discussion - 14th Jan 12z Onwards

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Looking through this morning its difficult to know quite what to make of everything tbh.

 

The charts ebb and flow as they pick up new signals and discard earlier ones so changes are to be expected. That said, I think there is little doubt that the pendulum has swung away from us. Personally I'm not that enamoured with the GEFS, but then again they are based on the old model.

 

On this basis I also had a look through the GEM ensembles (which I think are actually higher res than the GEFS) and they look pretty good at day 5.

 

So, jury's out. Given the timeframes involved I'd expect that we will start to see the final direction of travel more clearly this afternoon. Not saying the detail will be sorted but just the direction of travel in terms of the wider pattern in our part of the world (ie Atlantic or modest Easterly).

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Lets just enjoy what we can.I`m sure most of us will see some snow at some stage.

 

What we have to learn is 8/10 times when charts far our predict bitter deep set long lasting cold that most of the time nearer the event they more than often downgrade or shift to more mild scenario , thats what we get for living on this Island of ours on the edge of a huge atlantic ocean that carries a lot of warm water within it and plumps us right under or new atlantic lows.Alos couple with having an often flat and exceptionally strong High pressure what seems like year round to our south and sometimes over us in summer doesn`t make good chances for prolonged cold snow weather over our region. Of course this can happen as with Dec 2010 and a few times in 1980`s ( and before last years dismal winter we had 4 years with consectuive decent cold spells with snow)

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Can we please stick to what the Models are showing, There is a moaning/ramp thread already open, So some posts may be moved into there if you find yours missing.

 

Many Thanks, PM.

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Some might find this report of interest regarding Sunday/Monday wave development pushing up from Biscay Region. Our snow portal model service shows the main band of precipitation not to progress to far North and West. The main band from Hook of Holland to English Channel and clipping Kent coast ( Sun 12.00 ) By ( Mon 18.00 ) the associated front will have an under cut of cold air with precipitation turning to sleet and snow in Channel, south coast and Kent and moving away by ( Tues 21 .00 ) to affect the coastal regions of East Anglia. So this seems to indicate a limited extent of precipitation with the warmer mix now further south. See what tonight main models show.

C

 

that ties in closely with the gfs view. i think the ukgm + some others are much too far north. best advice would be to split them which leaves the northern extent into the home counties although i suspect s of the capital may the end game here. so uncertain.

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Some might find this report of interest regarding Sunday/Monday wave development pushing up from Biscay Region. Our snow portal model service shows the main band of precipitation not to progress to far North and West. The main band from Hook of Holland to English Channel and clipping Kent coast ( Sun 12.00 ) By ( Mon 18.00 ) the associated front will have an under cut of cold air with precipitation turning to sleet and snow in Channel, south coast and Kent and moving away by ( Tues 21 .00 ) to affect the coastal regions of East Anglia. So this seems to indicate a limited extent of precipitation with the warmer mix now further south. See what tonight main models show.

C

 

The Hi-res WRF has it clipping the SE as rain: post-14819-0-81579000-1421417276_thumb.p

 

The GEFS are split pretty equally into three clusters for the northern extent, Oxfordshire, Gatwick and English Channel.

 

The BBC forecast keeps changing it so I suspect it is very fluid. The spell of snow crossing SE from Wales tomorrow looks more promising at the moment but that band fractures as it passes over the SE:

 

post-14819-0-42647700-1421417616_thumb.ppost-14819-0-09775400-1421417616_thumb.ppost-14819-0-57823400-1421417615_thumb.p

 

Again it is a narrow band but could give some a covering?

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The Hi-res WRF has it clipping the SE as rain: attachicon.gifnmmuk-1-43-0.png

 

 

It's borderline and sure to change - but for what it's worth - our hi-res model has a rain/snow mix..

 

post-2-0-57094800-1421418156_thumb.png

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Just comparing the 00Z and 06Z GFS output and for the first 24-36 hours I can't remember seeing such few changes between runs for a long time. 

 

In fact if anything the 06Z seems to be a little less precise than they were at the 00Z.

 

Each run keeps ramping up the snow risk for the whole country, especially the South East which still has a lot to play with. Some areas of the north west are looking like they could see an honest to goodness whiteout.

 

I am very interested to see what the 12z does with this low pressure, the cold is nailed on now, that area of low pressure just makes working out where the snow will fall very difficult. As we always say snow is more nowcasting than anything else, we are certainly entering an exciting period where the models can change markedly from one run to the other, although as I say they haven't this morning!

Edited by throwoff

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that ties in closely with the gfs view. i think the ukgm + some others are much too far north. best advice would be to split them which leaves the northern extent into the home counties although i suspect s of the capital may the end game here. so uncertain.

 

HIRLAM also ties in with Carinthian's portal and GFS with rain spreading in across the far south towards the coast and up across the southeast Sunday morning before the band of precip pulls away SE Sunday afternoon:

 

post-1052-0-37539200-1421418472_thumb.gipost-1052-0-48294900-1421418489_thumb.gipost-1052-0-64921100-1421418501_thumb.gi

 

Would give a lot uncertainty over northern extent though, be a bit of a nowcast event IMO.

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Feb 1996

 

Rrea00119960206.gif

 

Now:

 

gfsnh-0-114.png?6

 

Yep - for the 3rd time I'll say Feb 1996 is the shape of this scenario. Can we be that lucky again?

 

Extended GFS op not that great - not watched this parallel (now "normal") GFS long enough to work out yet whether it also has the general progressive bias that its predecessor had. Anyone picked up any trends with this new version yet?

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Areas in the north are reporting heavy snow fall now, this wasn't clearly modelled on the runs that happened just a few hours ago. 

 

I think we are safe to say 'it has begun' it will be very interesting to see what the 12z says when we now it is snowing right now in those regions.

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Yep - for the 3rd time I'll say Feb 1996 is the shape of this scenario. Can we be that lucky again?

 

Extended GFS op not that great - not watched this parallel (now "normal") GFS long enough to work out yet whether it also has the general progressive bias that its predecessor had. Anyone picked up any trends with this new version yet?

 

Glad someone else sees it!

 

If we could get the height's more into the Arctic region, split the vortex, it would look uncanny.

 

Maybe, just maybe ...

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Areas in the north are reporting heavy snow fall now, this wasn't clearly modelled on the runs that happened just a few hours ago. 

 

I think we are safe to say 'it has begun' it will be very interesting to see what the 12z says when we now it is snowing right now in those regions.

 

There is a Met office warning for snow up north so maybe not too much of a surprise.

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WSI have just posted the EC weeklies:

 

  WSI_EuroEnergy
Colder than normal end to January over W Europe according to ECMWF. http://t.co/4c2Px607Ns
16/01/2015 15:03

 

  WSI_EuroEnergy
Less cold Europe during the 1st half of February 2015 according to ECMWF. http://t.co/AfgLG61rqw
16/01/2015 15:03

 

The start of Feb ties in with the recently updated JMA anomalies for Feb: post-14819-0-83443200-1421421079_thumb.p

 

March looks more promising for cold: post-14819-0-11919300-1421421079_thumb.p

 

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