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Model output discussion - heading into 2018

Paul

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Again the charts offer some optimism during the Christmas holidays with the Alaskan ridge morphing into an Arctic high and applying enough force to send the jet further south leaving some areas prone to the possibility of some wintriness. For more southern areas we would need to see the jet modelled even further south whether that is achievable is jet to be seen. The ECM is not very inspiring tonight it has to be said but that is just one op run.

Something maybe afoot in the far reaches of FI with a reasonable warming being forecast and making inroads into the Arctic rather than skirting round the surf layer. Of course it could quite easily disappear but something to watch.

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I've seen worse and of course a lot better but whilst the jet is tracking south theres always the chance of a surprise or two.

In terms of any slider low still up in the air. These are the ingredients we have to work from so its unrealistic to expect something outlandish to pop up given the models are generally agreed on the overall pattern.

However the exact track of the jet could be modelled further south or north nearer the time. A suggestion at day ten on the ECM  that we might see more amplitude towards the east USA.

Regarding the MJO still uncertainty as to whether this scoots into the COD and straight out into phase 2 or whether this goes into phase 1 then phase 2.

Overall its not the Christmas weather many might have hoped for but it is what it is. We rarely see the Christmas cards scenes at this time of year but at least we don't have a raging Bartlett high.

 

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1 minute ago, nick sussex said:

I've seen worse and of course a lot better but whilst the jet is tracking south theres always the chance of a surprise or two.

In terms of any slider low still up in the air. These are the ingredients we have to work from so its unrealistic to expect something outlandish to pop up given the models are generally agreed on the overall pattern.

However the exact track of the jet could be modelled further south or north nearer the time. A suggestion at day ten on the ECM  that we might see more amplitude towards the east USA.

Regarding the MJO still uncertainty as to whether this scoots into the COD and straight out into phase 2 or whether this goes into phase 1 then phase 2.

Overall its not the Christmas weather many might have hoped for but it is what it is. We rarely see the Christmas cards scenes at this time of year but at least we don't have a raging Bartlett high.

 

To be honest Nick by day 10 we are as far away from a scandy or Greeny high as i think we possibly could be.

 

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7 minutes ago, bluearmy said:

fwiw, ec op has a channel low T120-T144 which dumps on the moors

My reading of that was the tops of South West Hills, not for example NYorks. Is that yours? 

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20 minutes ago, Frosty. said:

Looking at the Ecm 12z next week, becoming rather cold beyond monday and unsettled too with strong winds at times and a wintry mix of rain, sleet, snow, ice and frosts..the snow especially with elevation and further north but overall, a much more interesting weather pattern than this week!!..time for upgrades too..:)

120_thickuk.png

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144_mslp850uk.png

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192_mslp850uk.png

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Honestly, this wouldn't be a bad result next week, at least a wintry flavour with 526 / 528 dam thicknesses and of course could turn out even better, like the Gfs 12z.☺😀😃..looks like an interesting christmas week ahead with potential for some snowy surprises / presents after xmas day.:reindeer-emoji:

Edited by Frosty.
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At midday on Monday the ecm has the wave over Stornoway with heavy rain in Scotland and the front down the west coast of Ireland an the rest of the UK in a moist and quite brisk south westerly.

By 12 on Tuesday the fronts has nipped east and into the North sea bringing rain to most places but the wave depression has deepened and become quire complex with the main centre just north east of Thurso. This could lead to gales and heavy rain for a time with snow on the mountains. Simultaneously a couple of waves have formed in mid Atlantic and are nipping south east with the first just south west of Ireland. This then pops along the Channel bringing rain to the south before losing it’s identity over Germany. All of this on a low level jet, well in excess of 100kts, leaving the NE seaboard band swinging around a transient mid Atlantic ridge.

ecm_mslp_uv850_natl_5.thumb.png.3503765939dc035c29ca2cd7e38573b4.pngecm_mslp_uv850_natl_6.thumb.png.4129d55b261d5787b8b644598ed75fca.pngecm_z500_anom_natl_6.thumb.png.11329a03184a1f5434aecddb5d9bd709.png

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Evening all :)

Not exactly in our neck of the woods but picking up on something Nick mentioned:

ECN1-216.GIF?21-0

Seriously high pressure over much of North America centred over one of those Midwestern states (Kansas, Nebraska, Iowa perhaps ?)

Wouldn't that inhibit the usual progression of weather systems across America and beyond ?

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1 minute ago, northwestsnow said:

To be honest Nick by day 10 we are as far away from a scandy or Greeny high as i think we possibly could be.

 

True but I think we're chasing too many rainbows. Theres a sense at times that its either marvellous or dreadful but I'd say the outlook is neither.

The outlook is mixed and although the 850's don't look that cold between day 5 and 8 I suspect the temps will be colder than expected. In heavier showers snow could get down to lower levels. And I think BA just mentioned a low running east at the base of the trough, these disturbances can surprise in this type of set up.

The outputs neither inspire me to do a Julie Andrews or crawl back into bed! :D

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17 minutes ago, bluearmy said:

fwiw, ec op has a channel low T120-T144 which dumps on the moors

I did that once when I was caught short while hiking. Europe seems to be a warm air magnet on the current ECM run. Be interested to see the ensembles.

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36 minutes ago, Daniel* said:

Hurricane force winds on that storm looks scary - explosive cyclogenesis is highly likely. Will we be impacted? Certaintly possible with jet not going over top.

AEA69668-6E9E-43FC-8A7F-EE35DA3C239B.thumb.gif.d277fd40fb49fad8187576413f33d119.gif

Yet another extreme solution produced by one of the models, a theme over the past 7 days.  If an output comes up with this kind of solution, it does suggest the run should be viewed with a lot of caution.  It's not impossible, we've had lows like this form over the past few winters but if something out of the ordinary is coming and going from the outputs then i feel something may be amiss with how the model is performing.

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I've definitely seen worse Xmas charts than what GFS is suggesting for next week...at least we have a better idea of what's what than we had back 'in the day': a five-minute-long Home Service forecast of 'unsettled with rain, sleet or snow at times'? And how was I supposed to know that the snow was atop Ben Nevis, the sleet half way up Men Nevis, and the rain everywhere else...?

These days, we'd all know better than to spend almost the entire festive period watching lampposts through the letterbox!:D

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2 minutes ago, swebby said:

Yet another extreme solution produced by one of the models, a theme over the past 7 days.  If an output comes up with this kind of solution, it does suggest the run should be viewed with a lot of caution.  It's not impossible, we've had lows like this form over the past few winters but if something out of the ordinary is coming and going from the outputs then i feel something may be amiss with how the model is performing.

Whether the low deepens to that extent or not, the general theme will remain the same. Cool and wet. Not inspiring output at the moment. Oh well, at least it's Christmas lol. 

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NOAA have just issued their January forecast and seem uncertain because of the MJO with apparently a conflict between the longer range modelling and the lagged response to the MJO. The main section important for us in Europe:

 
THE MJO WAS RELATIVELY INACTIVE IN NOVEMBER BEFORE BECOMING MORE ACTIVE DURING
DECEMBER OVER THE WESTERN PACIFIC. MJO FORECASTS INDICATE A SIGNAL MOVING
ACROSS THE AMERICAS AND EMERGING OVER THE INDIAN OCEAN BY EARLY JANUARY 2018.
LAGGED COMPOSITES BASED ON AN MJO OVER THE INDIAN OCEAN WOULD FAVOR RIDGING AND
WARMTH OVER THE EASTERN CONUS WITH TROUGHING AND COLDER TEMPERATURES OVER THE
WESTERN CONUS, AT ODDS WITH TRENDS AND MOST MODEL OUTLOOKS FOR JANUARY, SO THE
MJO IS A POTENTIAL SOURCE OF UNCERTAINTY DURING THE OUTLOOK PERIOD.

THE ARCTIC OSCILLATION (AO) IS FORECAST TO BE NEGATIVE AT THE BEGINNING OF
JANUARY. THAT WOULD IMPLY A COLDER SOLUTION FROM THE NORTHERN PLAINS TO THE
GREAT LAKES AND SOUTHEAST. THE STATUS OF THE AO BEYOND 15 DAYS IS UNCERTAIN, SO
THE AO WILL LIKELY BE MORE OF A FACTOR IN THE END-OF-MONTH UPDATE TO THIS
OUTLOOK.

 

That MJO induced upstream set up would normally see high pressure east USA, troughing in the Atlantic to the west of the UK, higher pressure to the ne however whats uncertain is whether we'll see a more digging amplified trough set up to the west which would help disrupt energy se and perhaps bring something colder from the east/ne.

So as you can see from NOAA they really aren't sure whats going to happen so its a case of seeing how things unfold as we head into January.

Edited by nick sussex
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2 minutes ago, nick sussex said:

NOAA have just issued their January forecast and seem uncertain because of the MJO with apparently a conflict between the longer range modelling and the lagged response to the MJO. The main section important for us in Europe:

 
THE MJO WAS RELATIVELY INACTIVE IN NOVEMBER BEFORE BECOMING MORE ACTIVE DURING
DECEMBER OVER THE WESTERN PACIFIC. MJO FORECASTS INDICATE A SIGNAL MOVING
ACROSS THE AMERICAS AND EMERGING OVER THE INDIAN OCEAN BY EARLY JANUARY 2018.
LAGGED COMPOSITES BASED ON AN MJO OVER THE INDIAN OCEAN WOULD FAVOR RIDGING AND
WARMTH OVER THE EASTERN CONUS WITH TROUGHING AND COLDER TEMPERATURES OVER THE
WESTERN CONUS, AT ODDS WITH TRENDS AND MOST MODEL OUTLOOKS FOR JANUARY, SO THE
MJO IS A POTENTIAL SOURCE OF UNCERTAINTY DURING THE OUTLOOK PERIOD.

THE ARCTIC OSCILLATION (AO) IS FORECAST TO BE NEGATIVE AT THE BEGINNING OF
JANUARY. THAT WOULD IMPLY A COLDER SOLUTION FROM THE NORTHERN PLAINS TO THE
GREAT LAKES AND SOUTHEAST. THE STATUS OF THE AO BEYOND 15 DAYS IS UNCERTAIN, SO
THE AO WILL LIKELY BE MORE OF A FACTOR IN THE END-OF-MONTH UPDATE TO THIS
OUTLOOK.

 

That MJO induced upstream set up would normally see high pressure east USA, troughing in the Atlantic to the west of the UK, higher pressure to the ne however whats uncertain is whether we'll a more digging amplified trough set up to the west which would help disrupt energy se and perhaps bring something colder from the east/ne.

So as you can see from NOAA they really aren't sure whats going to happen so its a case of seeing how things unfold as we head into January.

Well, the MJO has not been our friend these past few years so I won't be holding my breath. Thanks for that update though. 

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5a3c0ecf4584f_ScreenShot2017-12-21at19_42_25.thumb.png.66783bc367a7591bdad72c8b1f2e68d1.png 

Scotland obliterated by the Chinese model last few days of 2017 :bomb::rofl:

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4 minutes ago, blizzard81 said:

Well, the MJO has not been our friend these past few years so I won't be holding my breath. Thanks for that update though.

Yes well in recent years its been muted out by other factors  even when its been in a favourable phase for us.

 

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45 minutes ago, high ground birmingham said:

As soon as I saw that mini hurricane on EC 192+, I knew this run has to be put in the shredder. What nonsense

Perhaps overdone but a formidable depression could occur, look at that frigid cold arctic air collide with that subtropical warm, moist air a considerable gradient there, ideal for ‘beasts’ to form as seen in ECM.

 

997B3DFC-8304-4862-981E-DF9F3DAD3992.jpeg

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4 minutes ago, nick sussex said:

Yes well in recent years its been muted out by other factors  even when its been in a favourable phase for us.

 

That's the trouble with the MJO though. Too many other variables can override/mute the signal. 

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2 minutes ago, Daniel* said:

Perhaps overdone but a formidable depression could occur, look at that frigid cold arctic air collide with that subtropical warm, moist air a considerable gradient there, ideal for ‘beasts’ to form as seen in ECM.

 

997B3DFC-8304-4862-981E-DF9F3DAD3992.jpeg

Incredible how these last few years have seen those ultra cold uppers over the north east seaboard year in, year out. 

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8 minutes ago, Daniel* said:

Perhaps overdone but a formidable depression could occur, look at that frigid cold arctic air collide with that subtropical warm, moist air a considerable gradient there, ideal for ‘beasts’ to form as seen in ECM.

 

997B3DFC-8304-4862-981E-DF9F3DAD3992.jpeg

On the latest run though it would swing NE and weakens off NW Scotland. I agree though it's something to keep an eye on especially as lots of people will be out and about. 

image.png

Edited by Draig Goch
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6 minutes ago, blizzard81 said:

That's the trouble with the MJO though. Too many other variables can override/mute the signal. 

I often wonder why it gets so much attention when this is the case. NOAA update pretty much says they don't have a clue. LRWF are pants 

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1 minute ago, Longtimelurker said:

I often wonder why it gets so much attention when this is the case. NOAA update pretty much says they don't have a clue. LRWF are pants 

The MJO does seem to be a very fickle tool to say the least. It does my head in to be honest lol. 

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Ext eps depict signals for a genuine Euro trough towards the end of the run.

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Something that's always puzzled me about the MJO: Is it an 'external' signal derived independently of the models (like the QBO?) or is it, like the NAO, something that's extracted from ordinary model output, and thus little more than a kind of shorthand for whichever facet of global synoptics it's supposed to explain/simplify?:cc_confused:

I have a job discerning cause from effect...

 

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