Model Output Discussion - early October

[MATTWOLVES 3]

Yet again some spicy 12z ensembles coming out.... Now is it finally onto something, or does it still show tenancies for cold bias! I'm hoping there has been some improvement since last winter. Personally I think it's latching onto something, if I recall, it was the GFS that was pointing out one of our hot plumes during the summer by flagging up very warm ensembles a couple of weeks out! A quick glance at the ens show the control was yet again a beauty, and even the mean is beginning to trend down... All in all, me love it long time. 

[shaky]

Well something has clearly changed in favour of cold this evening cos ecm at 120 hours has now joined the gfs and brings the cold air in!!all of a sudden that mild south west wind that was forecasted has all but vanished for the weekend!!!bring on the frost i say!!

[Methuselah]

Definitely more 'cold' members appearing in today's GEFS 12Z ensembles; though, whether it's real or just this year's first Phantom...Who knows? But, given the GFS's well-documented cold bias, I'll no' be getting too excited, just yet.

   

   

[northwestsnow]

Cold high on EC this evening!!

Some lovely dry and hopefully frosty weather to end Oct and early November!!

[booferking]

Nice ecm the night dry and cold ecm 168hr below was dead cert 192hr 216hr would have shown a full on Greenland high maybe tomorrow it will..

[BlueHedgehog074]

12Z ECMWF think it’s going to be Winter at the weekend:

 

...while the 12Z NAVGEM think it’s going to be Summer...

(at least so away from the far North-West)

On a personal view, as nice as both scenarios would be, have a feeling the ECMWF will end up being a bit closer to the mark with its chillier outlook (especially with models, such as the GFS, supporting similar ideas). 

[Jordan S]

The temperature contrast for Friday by the GFS really is very impressive as autumn and winter airmasses clash.. 

A seasonal end to October plus a chilly Halloween and start of November if this gfs run verifies.. 

Edited October 21, 2019 by jordan smith

[Allseasons-Si]

1 hour ago, Mattwolves said:

Yet again some spicy 12z ensembles coming out.... Now is it finally onto something, or does it still show tenancies for cold bias! I'm hoping there has been some improvement since last winter. Personally I think it's latching onto something, if I recall, it was the GFS that was pointing out one of our hot plumes during the summer by flagging up very warm ensembles a couple of weeks out! A quick glance at the ens show the control was yet again a beauty, and even the mean is beginning to trend down... All in all, me love it long time. 

 

Yes there is Matt,a few days ago a lot of the gefs ens members was showing cold only for them to flip to mild ones recently then back to cold again today,lets hope that there is no more yellow or red cards being shown,we just want blue ones

tonight's cpc 6-10/8-14 day 500mb outlook shows there is a strong ridge into Greenland still.

 

 

[Frosty.]

Tonight's Ecm 12z ensemble mean is definitely going colder from the north, just like the operational...colder than the 0z for sure!

Edited October 21, 2019 by JON SNOW

[Allseasons-Si]

1 minute ago, JON SNOW said:

Tonight's Ecm 12z ensemble mean is definitely going colder from the north, just like the operational...colder than the 0z for sure!

Yes Karl,the HP cell is further west and into Greenland than the uk,hence a cold flow from the N/NW

12z/00z ten day mean.

 

[SMU]

Ive dismissed the ECM op for its progressive nature over the top of Greenland ( 168 > onwards )

NB same the other say- where it sweeps the high pressure aside from the west ...

ECM mean looks much lower with better pressure over NW greenland, also the 192 mean a lot closer to GFS mean-

ironically the swing to cold from ECM mean is almost identical to the GFS swing I posted earlier

Edited October 21, 2019 by Steve Murr

[feb1991blizzard]

9 minutes ago, Steve Murr said:

Ive dismissed the ECM op for its progressive nature over the top of Greenland ( 168 > onwards )

NB same the other say- where it sweeps the high pressure aside from the west ...

ECM mean looks much lower with better pressure over NW greenland, also the 192 mean a lot closer to GFS mean-

Yes- looks very convoluted around North American continent / Greenland / Iceland at 168, what do you think is happening lately with the ECM?, its usually the GFS that does this small  low / shortwave crazy thing.

Edited October 21, 2019 by feb1991blizzard

[ICE COLD]

6 minutes ago, JON SNOW said:

Tonight's Ecm 12z ensemble mean is definitely going colder from the north, just like the operational...colder than the 0z for sure!

It has indeed frosty the lowest the mean went down to this morning was around 3 it’s now dropped to 0 . And there’s  a lot more colder ens appearing now . 
 
ECM 00z 1st graph and 12z 2nd graph . 

[damianslaw]

Interesting model viewing today - some significant changes from what was shown over the weekend - back to a much colder theme for the latter part of the month, with a battle taking place between polar air and tropical maritime air. The key difference in the models today is the projected depth and position of the remnants of the split trough anchoring itself to our SW. Yesterday the models were showing a much more robust and rounded feature cutting off the polar air supply to the north quickly and thus ushering in a mild SW wind with heights pumping up from the near continent thanks to the increased pressure gradient. Today the models are showing a much shallower and stretched feature becoming elongated with a much less marked pressure gradient, hence much less in the way of height development to the south, allowing the polar air to have a much easier ride in nosing down on the trough and pushing it quickly aside, giving the northern half of the UK at least a very chilly end to the week - with snow quite possible to modest levels.

Thereafter heights are forecast to build through the UK towards the NW, which ties in with what the Ensembles have been showing for quite a while now - giving a chilly crisp and dry end to October - a cold high so lots of frost and possible fog.. 

Still a chance the models could have it wrong this evening and they revert back to what they were showing over the weekend, but the timeframes are much shorter now, and when you get a very quick about turn of pattern development in the 96-120 hr timeframe, and all models are on the same page, chances of them completely backing away in future runs is quite minimal, not to say a half way house or watered down version can occur.

After a predominantly unsettled first two thirds to October, might we end up with a very seasonal dry cold frosty end.. would be nice to see.

[Allseasons-Si]

nice mean height anomaly...

[January Snowstorm]

Big swing to cold in the last 12 hours or so. Certainly widespread frost looks likely for many. So encouraging to see heights so high to our West and North. If the trend is your friend it's all looking good as we head for Winter proper!

[Met4Cast]

EC weekly showing a switch to a +NAO just in time for winter..

[shaky]

Any news on icon 18z!!!

[feb1991blizzard]

1 minute ago, Met4Cast said:

EC weekly showing a switch to a +NAO just in time for winter..

Wouldn't worry about week 6 on that model, however, i actually agree a +NAO start to winter is very likely but for other reasons than the EC46 39-46 period showing it.

[feb1991blizzard]

1 minute ago, shaky said:

Any news on icon 18z!!!

 

[SMU]

ICON 18z shows up Saturdays transition very neatly with the cold airmass sliding SE...

[feb1991blizzard]

Another edge southwards on the 18z GFS compared to the 12z

[SMU]

GFS 18z continues where the 12z left off - 

with even more cold air undercutting & a nudge south

Snow possible over North Midlands -

@WillinGlossop

18z V 12z

 

[feb1991blizzard]

At 120 its another fairly significant improvement on the 12z with better and further North ridging behind the low as it clears East.

[shaky]

Any pics mate!!sorry am just out on my delivery rounds lol