Model output discussion - 5th December 2016 - Into Winter we go

[Summer Sun]

3 minutes ago, Dennis said:

A strong LOW

 

This is going to be a nightmare for forecasters given the low won't be forming till Thursday

GFS Para 00z

Maybe some back edge snow in the north and west

Plenty of changes ahead in the coming days no doubt

[Summer Sun]

Just looking at yesterday's JMA don't recall seeing a 1050mb high and 960mb low so close together before

[karlos1983]

I've not seen a TV forecast go past Thursday yet, which speaks volumes. Very tricky forecast period coming up. 

The Ensembles show that rather well with some pretty big differences in terms of pressure predictions on 24th/25th which are the dates of interest here 

we know a storm is coming, it's just when and where it is in relation to our part of the world, 100-200 mile differences will have a big impact. Not surprised the forecasters are waiting for more agreement, this could impact many at a time travel is very high. 

Edited December 19, 2016 by karlos1983

[karlos1983]

37 minutes ago, Summer Sun said:

Just looking at yesterday's JMA don't recall seeing a 1050mb high and 960mb low so close together before

I'm fairly certain that's terrain driven SS, not true heights. 

Edited December 19, 2016 by karlos1983

[Frosty.]

2 hours ago, Sir Saats a lot said:

Does anybody know if this Christmas period model output matches that of 1995. We have been having similar weather behaviour up here in Shetland. The Christmas period of 1995 brought some serious snow for us, 30 feet deep in places.

1mm of wet slush if you are lucky 

[Nick F]

25 minutes ago, Summer Sun said:

Just looking at yesterday's JMA don't recall seeing a 1050mb high and 960mb low so close together before

Such strong Greenland highs are a common trait of NWP trying to model mslp at 3000m high on the Greenland plateau! So surface pressure maps over Greenland don't truly reflect the pressure over the plateau, rather they reflect the frigid cold air on the plateau. If the temperature changes on the plateau the pressure maybe a lot lower the next day. The 960mb seemingly so nearby is actually more accurately depicted as the low is over open ocean/ sea level.

In an ideal world, NWP should blank out the mslp lines around mountain ranges and plateaus such as Alps and Greenland respectively.

Edited December 19, 2016 by Nick F

[Methuselah]

9 minutes ago, Frosty. said:

1mm of wet slush if you are lucky 

Good to see that even your silver linings are getting (pardon the pun) thin on the ground, Karl...

That said, the GFS in FI, together with the MetO's latest updates are looking increasingly optimistic...We have of course been there before!

Edited December 19, 2016 by Ed Stone

[Faronstream]

Right now it is safe to say that this christmas will be a very mild one, not extreme but still really sad outcome we had this year, now we can  just look forward until the last days of the year and hope that around new year will be frosty and some snow

Still high pressure over south europé and the typical  +NAO pattern in the GFS ensembles for 29th December, if this chart will become reality there will be even low possibility of snow in high latitude areas in all parts of europe

[karlos1983]

7 minutes ago, Faronstream said:

Right now it is safe to say that this christmas will be a very mild one, not extreme but still really sad outcome we had this year, now we can  just look forward until the last days of the year and hope that around new year will be frosty and some snow

Still high pressure over south europé and the typical  +NAO pattern in the GFS ensembles for 29th December, if this chart will become reality there will be even low possibility of snow in high latitude areas in all parts of europe

Hmm high parts of Scotland and Scandinavia perhaps but the rest of Europe, that's air sourced from the wrong part of the Atlantic if its snow your after 

that Euro high is a disgusting freak of nature and needs to do one!

i see, maybe I misunderstood your post actually, i think we basically say the same thing here. Low risk of snow. 

Edited December 19, 2016 by karlos1983

[Cheshire Freeze]

3 hours ago, radiohead said:

06Z GFS still showing a stormy Xmas Eve/Day  though the strongest winds confined mainly to Scotland and not as severe as previous runs.

Thankfully, the GFS has eased away from the storm force offerings it was bringing to large swathes of the UK yesterday. Still need to keep an eye on the situation however.

Edited December 19, 2016 by CreweCold

[Frosty.]

7 minutes ago, karlos1983 said:

that Euro high is a disgusting freak of nature and needs to do one!

 

 

 

 

 

Agreed, more salt needed to deal with the slimy Euro slug!

The models are firming up now on an unsettled christmas period with a succession of deep Atlantic depressions winging across the uk with mild incursions separated by colder interludes..preety standard stuff really.

Edited December 19, 2016 by Frosty.

[Backtrack]

19 minutes ago, Faronstream said:

Right now it is safe to say that this christmas will be a very mild one, not extreme but still really sad outcome we had this year, now we can  just look forward until the last days of the year and hope that around new year will be frosty and some snow

Still high pressure over south europé and the typical  +NAO pattern in the GFS ensembles for 29th December, if this chart will become reality there will be even low possibility of snow in high latitude areas in all parts of europe

Disagree with the 'very mild' Christmas statement. Looks like PM flow with strong winds, frequent rain, hail, sleet for low levels, western coasts especially, and snow over the Pennines and mountains of northern Scotland. 

Traditional winter weather, so whilst it's not going to be a rare 'white christmas'. It'll at least feel more seasonal than as of late. According to the latest GFS. 

Edited December 19, 2016 by Backtrack

[Frosty.]

6 minutes ago, Backtrack said:

Disagree with the 'very mild' Christmas statement. Looks like PM flow with strong winds, frequent rain, hail, sleet for low levels, western coasts especially, and snow over the Pennines and mountains of northern Scotland. 

Traditional winter weather, so whilst it's not going to be a rare 'white christmas'. It'll at least feel more seasonal than as of late. According to the latest GFS. 

I agree it won't be a very mild christmas but it will be mildish overall.

[West is Best]

26 minutes ago, Faronstream said:

Right now it is safe to say that this christmas will be a very mild one, n

Assuming by 'Christmas' you mean at least Christmas Eve, Christmas Day and Boxing Day (rather than the traditional twelve days of Christmas) this is still a pretty wild comment, if I may be so bold. There's nothing 'very mild' about the 24th:

Nor the 25th:

Nor indeed the 26th:

[karlos1983]

5 minutes ago, Frosty. said:

I agree it won't be a very mild christmas but it will be mildish overall.

Never fear frosty, winter will fight back, I can feel it in my bones!

[West is Best]

3 hours ago, Sir Saats a lot said:

Does anybody know if this Christmas period model output matches that of 1995. We have been having similar weather behaviour up here in Shetland. The Christmas period of 1995 brought some serious snow for us, 30 feet deep in places.

At the moment I'd say that parts of Scotland are likely to see significant snow, with whiteout conditions at times.

[karlos1983]

6 minutes ago, West is Best said:

Assuming by 'Christmas' you mean at least Christmas Eve, Christmas Day and Boxing Day (rather than the traditional twelve days of Christmas) this is still a pretty wild comment, if I may be so bold. There's nothing 'very mild' about the 24th:

Nor the 25th:

Nor indeed the 26th:

In fairness though, there is nothing very cold about those charts either. Assuming proper cold is what the majority are looking for. Snow to low levels is pretty unlikely.

[Chris.R]

 Is it just me who's confused at the moment? 

[legritter]

Just hoping that met office modeling of high pressure setting up to our West in new year is correct ,computers may be saying high to West but it could rear it's head further east and south as a  SLUG ,oh how I hate SLUGS ,or they could be on the ball and hopefully we can see a link up to our north ,time will tell ,cheers 

[Daniel*]

Hmmm  

Posted Friday at 00:20

EC MONTHLY: again like last run. Blocked & dry anomalies developing 1st half Jan as heights move W to north of UK. Colder than avg anomalies southern UK 2nd week Jan (not seen that signal for a while!). East-NE flow. So continuity between last runs and ditto with GloSea5. 

Don't shoot messenger. Just describing the output: not making any comment on outcome.

81 people like this

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GFS 06hrs somewhat advertising this...

 

[Frosty.]

7 minutes ago, West is Best said:

At the moment I'd say that parts of Scotland are likely to see significant snow, with whiteout conditions at times.

That's OTT, any hill snow will quickly melt as a mild incursion comes through, one after the other.

[Timmytour]

19 minutes ago, Chris.R said:

 Is it just me who's confused at the moment? 

No I think the models are as well!  

Half expect them to be showing the storms running further south tonight to maintain the inconsistency....

Edited December 19, 2016 by Timmytour
missed out "as"

[Chris K]

2 minutes ago, Changing Skies said:

Hmmm  

Posted Friday at 00:20

EC MONTHLY: again like last run. Blocked & dry anomalies developing 1st half Jan as heights move W to north of UK. Colder than avg anomalies southern UK 2nd week Jan (not seen that signal for a while!). East-NE flow. So continuity between last runs and ditto with GloSea5. 

Don't shoot messenger. Just describing the output: not making any comment on outcome.

81 people like this

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GFS 06hrs somewhat advertising this...

 

Yes, but until we start seeing these charts entering a reliable time-frame with cross-model support rather than T+384 op run, it's just eye candy.

Although I would not wish disruption or damage on anyone, there is at least some interest in the outputs this week with potential stormy weather sweeping in. I would imagine this will be the main focus until details become more clear on track/depth and positioning.

[Methuselah]

Aye, we all need wait and see; even if today's upcoming runs point us in our desired direction, it'll be still much too early to break out the bubbly!

[West is Best]

21 minutes ago, karlos1983 said:

In fairness though, there is nothing very cold about those charts either.

I was responding to the comment that Christmas will be 'very mild.'

According to the current models it's simply not true.

Edited December 19, 2016 by West is Best