Jump to content
Snow?
Local
Radar
Cold?
IGNORED

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


Paul

Recommended Posts

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

Always good to have a little break from model watching.. the path towards a more 'northerly type airstream' as we hit New Year as shown by the models in the immediate run up to christmas day, continues, and this path is now firmly laid with no obstacles in the way. The coming days will bring quite chilly settled conditions away from Scotland and N Ireland with frost and lingering fog, so feeling more seasonal, but becoming quite cloudy by the weekend and milder as we pull in a moist atlantic airstream - all models then show a quick sudden shift in the position of the high pressure i.e. out west, which will have the affect of pulling down a northerly shot, nothing potent or long lasting, perhaps a 2 day colder interlude with wintry showers in northern and eastern parts, and some sharp frost in western parts. 

ECM and GFS are very similiar in their output for the first week of the New Year, mid atlantic high, sat just to our west, but not ridging northwards sufficently to maintain a more direct northerly flow, or collapsing over the country to pull in milder westerlies, instead we see a fairly settled spell but with some frontal activity from the NW by the end of the first week, giving some rain, with strong chance of sleet/snow to low levels in the north behind frontal activity. This pattern could be a long lasting one, we could easily see a more pronounced frontal activity cell move down across the country which would pull in colder NE flow behind.

So after a very mild snowless December despite a fairly promising start, January looks like starting off on quite a cold note (just average really), but with a wintry flavour, with frost, fog, chance of some snow for some, what a pity this synoptical change has arrived a week late..The past 5 Januaries have started off on a very dull grey wet mild note, so quite refreshing to see this one will be a bit different with some brightness to blow away the gloom normally associated with the time of year.

  • Like 5
Link to comment
Share on other sites

Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

Looks like the models went out to the pub around xmas with a notable dip in performance.

Link to comment
Share on other sites

Posted
  • Location: Ireland
  • Location: Ireland
9 minutes ago, The PIT said:

Looks like the models went out to the pub around xmas with a notable dip in performance.

I think that shows verification stats for T120, so it would have been the model output from 5 days before that which would have been poor.

Link to comment
Share on other sites

Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire
10 minutes ago, The PIT said:

Looks like the models went out to the pub around xmas with a notable dip in performance.

I don't know if the lack of data over xmas is true or not and in truth nobody on here does either.

Im sure some will shout me down for this and my reply will be do you know for a fact the usual amount of weather ballons were launched on xmas day?? What about the aircraft dropping raidosondes?? Some seem to suggest the only data used is via satellite

Link to comment
Share on other sites

Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
Just now, TEITS said:

I don't know if the lack of data over xmas is true or not and in truth nobody on here does either.

Im sure some will shout me down for this and my reply will be do you know for a fact the usual amount of weather ballons were launched on xmas day?? What about the aircraft dropping raidosondes?? Some seem to suggest the only data used is via satellite

I suspect it's lack of data which caused the drop. Overall though they don't badly it would be nice to be able to get that accuracy further out.

Link to comment
Share on other sites

Posted
  • Location: Upper Tweeddale, Scottish Borders 240m ASL
  • Location: Upper Tweeddale, Scottish Borders 240m ASL

What would cause a lack of data around 18/19 December?  That's what that graph shows.

  • Like 5
Link to comment
Share on other sites

Posted
  • Location: Isle Of Lewis
  • Weather Preferences: Wild!
  • Location: Isle Of Lewis

Far more opportunities exist for colder weather to topple in down from the NW. Regardless of what model is analysed. I feel far more confident that we will have wintry weather in January compared to a very zonal second half of December.

Optimistic yes... pessimistic definately not.

 

Link to comment
Share on other sites

Posted
  • Location: St rads Dover
  • Weather Preferences: Snow, T Storms.
  • Location: St rads Dover
25 minutes ago, radiohead said:

I think it's PRX on this.

cor_day5_HGT_P500_G2NHX.png

It looks like it's doing quite well, on that, unless I'm reading it wrong.

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire
9 minutes ago, shuggee said:

What would cause a lack of data around 18/19 December?  That's what that graph shows.

Run out of helium:yahoo:

  • Like 4
Link to comment
Share on other sites

Posted
  • Location: Hessen, GERMANY
  • Location: Hessen, GERMANY
7 minutes ago, snowwman said:

So basically, from what I can make out, it's done no worse than GFS and may even be somewhere between GFS and ECMWF. Tells me that perhaps we should taking this model's output more seriously.

In fact, purely on verification it ties in this period with UKMO.  Maybe worthwhile watching the 12z on each day and see where it's trending...

Edited by Nick B
  • Like 1
Link to comment
Share on other sites

Posted
  • Location: .
  • Location: .
16 minutes ago, TEITS said:

I don't know if the lack of data over xmas is true or not and in truth nobody on here does either.

Im sure some will shout me down for this and my reply will be do you know for a fact the usual amount of weather ballons were launched on xmas day?? What about the aircraft dropping raidosondes?? Some seem to suggest the only data used is via satellite

Fergie posted earlier that that is an old wives tale. Zero difference

  • Like 4
Link to comment
Share on other sites

Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire
9 minutes ago, Nick L said:

The weather industry does not stop because it's Christmas. The lack of data (which amounts to a small amount of aircraft data) being put into the models over Christmas has a negligible effect, and there have been studies into it. This needs putting as a header into this thread every Christmas.

How do we know it has a negligible effect. If a butterfly flapping its wings can change the outcome then surely lack of data can do the same. Also do you know the exact amount of weather balloons launched on a normal day and how many on xmas day. If you cannot answer then you cannot say Xmas model output isn't affected.

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: st albans
  • Location: st albans

I'm sure NOAA will be delighted to read the members of NW have decided to take the multi million pound gfs upgrade seriously!

since it became available I am taking it far more seriously than the normal gfs

lets see if the current trend to develop a week 2 more west based neg NAO begins to show on the normal gfs. Of course, week 2 op output isn't for close analysis in any case.

  • Like 6
Link to comment
Share on other sites

Posted
  • Location: Bristol
  • Weather Preferences: Thunderstorms and Snowstorms
  • Location: Bristol
34 minutes ago, shuggee said:

Let's have a look at the last three GFS 00zs for this coming Tuesday (03 January) at 00:00 (i.e. late Monday into Tuesday):

3x00zs Tues 00h00.JPG

So left to right that's:

1. Today's GFS 00z at T+174,

2. Boxing day GFS 00z at T+198

3. Christmas day GFS 00z at T+222

Not sure where the inconsistency/downgrades are?  

Fair point, but I think people who are talking about downgrades are unclear, there are no downgrades in regards to the possible temperatures we may receive. I think the downgrades people are talking about are in regards to the lengthliness of the cold spell.

Link to comment
Share on other sites

Posted
  • Location: Ireland
  • Location: Ireland
18 minutes ago, snowwman said:

So basically, from what I can make out, it's done no worse than GFS and may even be somewhere between GFS and ECMWF. Tells me that perhaps we should taking this model's output more seriously.

Indeed. It is the upgraded version of the GFS and eventually it will take over as the new "regular" GFS so we do need to take it seriously.

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Ireland
  • Location: Ireland
16 minutes ago, TEITS said:

How do we know it has a negligible effect. If a butterfly flapping its wings can change the outcome then surely lack of data can do the same. Also do you know the exact amount of weather balloons launched on a normal day and how many on xmas day. If you cannot answer then you cannot say Xmas model output isn't affected.

From what I know, I don't believe there are any changes in weather balloon schedules because of Christmas Day.

I remember somebody from the NCEP posted on an American weather forum a few years ago that the vast majority of data that goes into global models now comes from weather satellites and automatic sensors anyway. 

Edited by radiohead
Link to comment
Share on other sites

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