Model Output Discussion - 18z 31/10/15 onwards

[Costa Del Fal]

Easterly incoming

 

gfsnh-0-300.png

 

all just for fun of caurse at this stage but it is nice to look at though.

Not a proper easterly at all! It doesnt even turn out to be one after. Not that cold with air coming from the Med!

[marksiwnc]

Easterly incoming

 

gfsnh-0-300.png

 

all just for fun of caurse at this stage but it is nice to look at though.

Interesting that as nick Sussex said this afternoon that there looks to be a huge cold blast into to the plains in America.. This could be one of the outcomes on the table. Push the high pressure a bit further north and we could be looking at a cold spell.

[Allseasons-Si]

That Easterly came from the mild source straight from the Med.

 

Yes i know pip,but i was looking at the bigger picture,it looks a whole lot better than the 06z(hemispheric wise),baby steps

[Mucka]

Not a proper easterly at all! It doesnt even turn out to be one after. Not that cold with air coming from the Med!

 

TBH what GFS came up with in deep FI is unimportant. What is important are the changes to the NH profile in that run up to day 10 from previous GFS runs.

Hopefully it will get repeated and if it does we are sure to see some cold patterns emerging in the further reaches of FI.

Basically it would just load the dice a little in our favour if it is onto something.

[Cloud 10]

Not the worst chart i've seen for the first day of winter...

 

 

 

....maybe some stratospheric going's on as well

 

[festivalking]

UKMO still having none of it.

Great post.

Word of caution if the UKMO is not on board all other models should not be taken at face value.

Edited November 15, 2015 by festivalking

[MPG]

Great post.

Word of caution if the UKMO is not on board all other models should not be taken at face value.

Yes seen it all before, no UKMET leads to disappointment.

[Captain Shortwave]

Again the question is how cold would the UKMO be? It is difficult when we can't see the 850s, but to be honest once we see the string of lows clear the east coast then by that time we will pretty much in a polar maritime flow rather than anything source from the Arctic. 

The set up doesn't exactly inspire much confidence in generating convection either with a surface ridge already pushing in behind the cold front which will probably inhibit convection. 

 

The GFS looks pretty decent for the northerly, especially over Scotland with snow to low levels even on Friday.

 

The GEM has a northerly too, but at this time determining the detail with regards to Friday onwards as the models are playing around with small features within that trough, ultimately we won't know how these will develop and track for a couple of days yet and as such we won't know when and how potent the cold snap will be.

 

As for beyond this, the GFS has a very slow moving pattern whilst the GEM returns the zonal train to the Atlantic/Europe sector. To be honest I haven't got a clue 

Edited November 15, 2015 by Captain shortwave

[The PIT]

Great post.

Word of caution if the UKMO is not on board all other models should not be taken at face value.

It seems that UK met office maybe ignoring there own model judging by this evenings forecast. Normally one discounts the odd model out but sometimes they're right.

[Frosty.]

The Gfs 12z shows an Arctic blast next weekend, our first cold snap, lovely stuff, some of us will have snow showers and there will be icy patches and widespread frosts early and late. BBC weather and Met office now on board too so enjoy an early taste of winter, the way things were looking quite recently, there was nothing remotely like this forecast but it's going to turn much colder everywhere by next weekend. It's a bonus cold snap before winter!..Enjoy

Edited November 15, 2015 by Frosty.

[knocker]

Tweet from MV

 

Big changes coming to the N. Hem pattern. Arctic air mass intrusions are looking likely o/the W. US & Asia T-giving

 

[MR EXTREMES]

gefs not to shabby either cold northwest wind right from greenland deep cold to our east.

vortex being pushed and pulled it looks like nh really having a shake up.

 

but on the other hand don't look like lasting very long at all but at least its cold to our east north east for later in winter.

[SMU]

Just before the ECM fires up its worth noting that the post 168 the GFS / GEFS & ECM arent really showing much signs of forecasting the jet to increase - there must be a significant disconnect between the strat zonal wind - running at peak velocity V the mean & the trop vortex...

This is resulting in a large void of +VE height remaining in the atlantic as we head towards FI -

This will preclude lots of exciting runs for cold-

Im not saying its odds on, however this could be a cold spell rather than a cold snap - with a whiff of pressure rises over greenland & scandi theres all to play for .....

S

[summer blizzard]

Tweet from MV

 

Big changes coming to the N. Hem pattern. Arctic air mass intrusions are looking likely o/the W. US & Asia T-giving

 

According to Cohen the pattern of a Siberian High and cold air pouring into the Orient is exactly what we want to see for the SAI to start driving the winter pattern and produce the -AO given our great snow gains south of 60N.

[bluearmy]

Incidentally, the gfs op splits the strat vortex up to 30hpa at the end of its run.

Edited November 15, 2015 by Polar Maritime
To remove deleted quote.

[Polar Maritime]

Incidentally, the gfs op splits the strat vortex up to 30hpa at the end of its run.

 

Here we go Blue.

[Mucka]

Main model NH comparison 144h (Worse to first in amplification?)

 

 

Could do with the ECM pattern being a tad further West so ppn isn't killed off but not bad at all.

 

Meanwhile GFS1 12z ensembles

 

 

Probably the coolest set yet with just a hint of a double dip.

Looking through them they are much improved in deep FI for potential renewed blocking/cold patterns setting up early Dec compared to previous runs.

We will need to see that become a trend before getting to excited though and of course it is avery long way out yet.

Back to this upcoming cold snap...

 

JMA 144 chart brings in the coldest uppers of all the models worth taking note of.

 

Edited November 15, 2015 by Mucka

[Eskimo]

Ooooft!     

 

 

[Mucka]

JMA probably the stand out run of this evenings models. 192h 

 

[Allseasons-Si]

Reload from the north

 

 

got to say,i am loving these charts @ the moment

[MR EXTREMES]

return of the turtle ecm lol

 

 

cold air gets mixed out but good few days of cold from the ecm.

 

[nick sussex]

Looks like a dramatic change for Europe with the limpet Euro high being replaced by lower heights and high pressure to the west. This change will be met with a great deal of relief for the European ski resorts.

 

Then at T216hrs the ECM has followed those NCEP USA state discussions in terms of upstream pattern and will hopefully deliver us a nice Scandi high at T240hrs.

[SMU]

As mentioned earlier ECM filling the void of the atlantic full of ridging at 216....

Could be interesting this at 240!

S

[Daniel*]

+240

Not quite sure how we'll go forward here. Overall a cold run.

[nick sussex]

Very happy with that ECM, we don't quite get the Scandi high at T240hrs but its output is similar to the 00hrs and I think a west Scandi high/ east Greenland high combo could be on the cards. Not sure whether we have a name for that yet!

 

Overall the outlook is looking colder and the jet looks uninterested in terms of blasting east after the high topples, lots of detail yet to be decided but certainly its a relief to see that Euro high leave the scene.