Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Model output discussion - The Hunt For Cold


Paul
Message added by Paul

If you're hunting for cold potential in the model output, this thread is for you. But if you'd like to look more widely at the models, please head over to the general model discussion thread.

Recommended Posts

Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.
1 minute ago, bluearmy said:

At this stage we have the gfs op and gefs mean the most progressive towards deep cold. The ec op and gfsp less so. The highest resolution models not in such a hurry to get to where we want to be ...... just have to enjoy watching the data being munched in and spewed out every 12 hours ..........

Yes, kind of feel that we are on a hiding to nothing tonight (presuming the eps 10-15 are not spectacular), we cant really make any big steps forward until the EPS / OP come out tomorrow, but we could make a big step back though if the GFS / GEFS downgrade significantly.

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Hull
  • Weather Preferences: Cold Snowy Winters, Hot Thundery Summers
  • Location: Hull

Looks like this will be the first run of the season where I keep tapping F5 on wetterzentrale for the GFS to update!! The behaviour of that low at T120 is a big step in determining whether we get retrogression or not! It'll start rolling out in 10 minutes...

I would love to see a cold NE'ly wind as it would pack some seriously heavy snow showers here as a result of the warm North Sea.

ECM I think is the more likely option but that is at least rather cold and crisp at times. An uneventful run but loads of cold stacking to our east. I'd happily wait patiently for -10C uppers engulfing the UK with an easterly... but given the cold pool to our north we could get a really notable early cold spell! Provided the jigsaw pieces fit in place.

Fingers crossed eh? I think ECM is more likely but its no big loss if it verifies. After all it is still only November but its been a long while since the last proper chilly arctic northerly.

Edited by Quicksilver1989
  • Like 2
  • Thanks 1
Link to comment
Share on other sites

Posted
  • Location: Wantage, Oxon
  • Weather Preferences: Hot, cold!
  • Location: Wantage, Oxon

Comparison of ICON 18z T120 with GFS 12z at same time:

image.thumb.jpg.f794359fc060f077ae16a02616a63d27.jpg

image.thumb.jpg.040ad2c73b822a88a8a09b7112f7563c.jpg

That low to the left, GFS much easier from there to take it under,suspect if ICON went on it would follow the ECM? Difficult to tell, and T120 is the end of the run!

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

Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire
1 minute ago, Mike Poole said:

Comparison of ICON 18z T120 with GFS 12z at same time:

image.thumb.jpg.f794359fc060f077ae16a02616a63d27.jpg

image.thumb.jpg.040ad2c73b822a88a8a09b7112f7563c.jpg

That low to the left, GFS much easier from there to take it under,suspect if ICON went on it would follow the ECM?

Looks an improvement on its 12z run to me.

That LP is not the only factor in deciding whether we get retrogression or not. It's also the orientation of the block and how much in the way of lower heights & resultant cold pooling gets advected underneath the HP to maintain its integrity and structure. If you get both the slightly sagging HP and upstream LP that refuses to split energy sufficiently, you get the ICON of earlier. 

  • Like 6
Link to comment
Share on other sites

Posted
  • Location: st albans
  • Location: st albans
4 minutes ago, feb1991blizzard said:

Yes, kind of feel that we are on a hiding to nothing tonight (presuming the eps 10-15 are not spectacular), we cant really make any big steps forward until the EPS / OP come out tomorrow, but we could make a big step back though if the GFS / GEFS downgrade significantly.

Big step back from where though? we are putting the bits in place to get to a proper wintry period approaching mont(h end and into December.......... if you are expecting something notable to arrive before then, perhaps you will indeed be disappointed..... my advice would be to have slower expectations- then you may end up pleasantly surprised in the short term and likely satisfied in the longer ....

  • Like 6
Link to comment
Share on other sites

Posted
  • Location: Wantage, Oxon
  • Weather Preferences: Hot, cold!
  • Location: Wantage, Oxon
2 minutes ago, CreweCold said:

Looks an improvement on its 12z run to me.

That LP is not the only factor in deciding whether we get retrogression or not. It's also the orientation of the block and how much in the way of lower heights & resultant cold pooling gets advected underneath the HP to maintain its integrity and structure. If you get both the slightly sagging HP and upstream LP that refuses to split energy sufficiently, you get the ICON of earlier. 

Yes, agreed it's an improvement on ICON 12z, just checked archived run, I was comparing with the (gold standard) GFS 12z.

Link to comment
Share on other sites

Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl

Increasing odds now on a possibly lengthy protracted period of below average temperatures, once we start next week - not been able to say that since the infamous beast from the east.. Alas, major changes on the way and this time next week will feel decidedly different to now. 

GFS does appear to be more progressive than ECM this evening sending heights quickly to Greenland and allowing a deep trough to pull down into scandi with embedded frigid air, alas ECM suggesting heights may languish more to our direct north maintaining a very dry cold easterly feed, but preventing a possible arctic continental outbreak to end the month. Indeed GFS charts today are almost a carbon copy of late November 2010 - but not quite..

Its a pity I will be out of the UK from 24th Nov - 3rd Dec to miss what might be a notable wintry period not seen so early since 2010 (but lets not get ahead of ourselves just yet).

The jetstream profile forecast for next week is showing a shift to energy being transported into the southern arm - longer term this may do battle with heights to our north, and with it continuing to look very ragged and weak for the time of year, I wouldn't be surprised to see it come unstuck. 

Since March it seems like we have had a permanent high pressure near our shores, shifting position over time sometimes to our north, sometimes NW, sometimes to our east, sometimes our SE sometimes west, its been an ever present feature - an abnormal year.

  • Like 6
Link to comment
Share on other sites

Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.
4 minutes ago, bluearmy said:

Big step back from where though? we are putting the bits in place to get to a proper wintry period approaching mont(h end and into December.......... if you are expecting something notable to arrive before then, perhaps you will indeed be disappointed..... my advice would be to have slower expectations- then you may end up pleasantly surprised in the short term and likely satisfied in the longer ....

Oh i would absolutely settle for month end, i just sense though that the eps need to start upgrading for that to become evident, dont forget the end of the ensemble suites takes us nearly to month end now, however though, even if we get a number of failures, another chance wont be long coming along.

Link to comment
Share on other sites

Posted
  • Location: leicester
  • Location: leicester
13 minutes ago, Mike Poole said:

Comparison of ICON 18z T120 with GFS 12z at same time:

image.thumb.jpg.f794359fc060f077ae16a02616a63d27.jpg

image.thumb.jpg.040ad2c73b822a88a8a09b7112f7563c.jpg

That low to the left, GFS much easier from there to take it under,suspect if ICON went on it would follow the ECM? Difficult to tell, and T120 is the end of the run!

That is a good improvement there from icon!!looking forwardd to the gfs all of a sudden!!gona be really hard to beat the last run though!!

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl
1 minute ago, feb1991blizzard said:

Oh i would absolutely settle for month end, i just sense though that the eps need to start upgrading for that to become evident, dont forget the end of the ensemble suites takes us nearly to month end now, however though, even if we get a number of failures, another chance wont be long coming along.

As a lover of a cold snowy build in to christmas and lasting into New Year (think 2009), I'd be a very happy man if we were say 3 weeks on from where are now, GFS charts being shown today coming to fruition (cold spell starting about 13 December) - perfect timing.

  • Like 8
Link to comment
Share on other sites

Posted
  • Location: Solihull, Midlands. (Formerly DRL)
  • Weather Preferences: Sunshine, thunder, hail & heavy snow
  • Location: Solihull, Midlands. (Formerly DRL)

Doesn’t get used often, probably mostly due to it not being the best performing model. However, the NAVGEM 12Z is an example where, although the Low Pressure system to the West of the North-Eastern UK blocking High Pressure still lifts away Northwards and merges with the other Lows,

8F89065A-AD99-4F89-991E-DE2610D22033.thumb.jpeg.303c6f53884be66ec3e12e31b2612842.jpeg

...we end up with this at 180 hours:

4D51F434-A021-44C4-943D-E795630675AD.thumb.png.279b4f4df951e490e36747196f117238.png

Still fairly far away from perfect for those wanting to take a ride on the Polar Express train. Though perhaps some possibilities for something more wintrier and colder to develop. The blocking High over Northern UK a little bit too close to let the real cold in from the North-East around that time-frame. But a different take from the 12Z ECMWF - the High is orientated more favourably, aligned South-West to North-East to our North with Low Pressure over Southern/South-Eastern Mainland Europe keeping the blocking High propped up. 

I suppose it would depend how that ridge in the Atlantic and the Lows to the North-West of the 2 High Pressure areas would behave. Maybe if the run went out further, that deeper upper cold pool to the East of France could head further West towards (Southern) U.K.

6AFEE49B-2AC0-4ECB-B3B5-E677F92BD8B9.thumb.jpeg.1716435e102ab90f1a35812ddba14a83.jpeg

It is just one run and not worth worrying too much about, since I imagine things will keep chopping and changing. An even if an Easterly with sleet and snow fails, will at least be looking forward to some drier, more settled, weather (along with likely morning frost and mist) however long it lasts. Plus, other chances for wintry weather is always possible as we head further towards Christmas and into the New Year.

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

Posted
  • Location: st albans
  • Location: st albans

Looking at cpc 8/14 and comparing with 12z gefs and eps ( shhh ....no one may notice) for same period, you can see that cpc are hedging their bets a bit ...

62C0B1AC-ABB0-4371-BF17-0C9CE6BC096A.thumb.jpeg.2ca8f6e2d5c7705d358da7959f9d5135.jpeg 90CEF25B-A5B3-48D1-BF74-A7DEE35762FE.thumb.jpeg.da42c8806380c0f992e0badc428e95e6.jpeg4E2E1166-A187-44D8-9478-FD9108088DD4.thumb.jpeg.a10ccc7d02a0ac0e1ce648b1fb5094d8.jpeg

The wrap around of low anomalys through Europe very promising ........ eps look more settled for uk ... cpc have lower than average confidence upstream due to the pattern change ...... 

  • Thanks 2
Link to comment
Share on other sites

Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl
16 minutes ago, feb1991blizzard said:

I think its wasted over xmas, i like a blizzard at 4pm on a monday afternoon rush hour for maximum impact.

Sorry for going slightly off topic - in reply, In 2009 and 2010 disruptive snowfall arrived weekend prior to christmas - it caused chaos given many people were travelling away to wherever there wanted to be for christmas - an optimum time for disruption. Agree a major snowfall on christmas day itself would cause significantly less disruption than on an average Tuesday rest of the winter.

Perhaps the most disruptive time is a that first Monday back after christmas/new year - this year occurring quite late on the 6th January - a major snowfall then would cause significant disruption. Jan 2010 came close to doing this, the snow was on the first Tuesday instead of Monday, and many schools were then closed rest of the week - indeed for some an extended christmas-new year holiday.

  • Like 4
Link to comment
Share on other sites

Posted
  • Location: Market Rasen
  • Weather Preferences: Snow Frost Fog Thunderstorms
  • Location: Market Rasen

Eyes down for the GFS 18z yes it's the pub run but interesting if it sides with the ECM or dare I say it upgrades further!

Edited by Mr snowman 2018
Spelling mistake
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

The double advection is on...

Siberian...or greeny...

Lets see the 18z take.....

The hp cell in confused situ...mirrored in the output!!

gfsnh-0-108.png

Link to comment
Share on other sites

Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire

The GFS splits the jet at 126 hrs...but my God that was knife edge stuff there. Small nuances from hereon in will have massive differences on that particular phase of the progression.

So knife edge that this run will tell us nothing.

Edited by CreweCold
  • Like 8
Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
×
×
  • Create New...