Model Output Discussion - Into November 2019

[MATTWOLVES 3]

The op from the ECM mean was a little on the colder side... The mean just under 0C...but more positively there are a fair amount of runs nudging that - 5 mark.... So we keep with the colder theme moving forward.... Ps.... Some absolutely brill posts in here today, just when you think you can't learn anymore, you get proven wrong time and time again. Enjoy the rest of your evenings..

[SMU]

Just before the 18z gets going there seems to be a window. appearing about the 130-140 Mark ( Sat ) where the approaching atlantic ( on its NW > SE Axis ) slides into colder air embedded over NW England & Scotland- 

This highlights some wintry potential- I haven't got the ECM partial thickness however using Meteociel & the 1000HPA contour the 500 Thickness through Scotland is ~532 DAM so certainly >200-300M would be the line.

North Wales North is the cut off.

Also the current trajectory isnt that acute however as we know when we get these tilted axis they normally sharpen up as we get closer to T0 ( modifications in the 48 - 72 timeline always seem to make them more acute )

NB ECM 2 days ago V tonights 72 ( first ) - The new chart at day 3 is sharper & introduces less milder flow ahead -

We now take tonights ECM 144

Remember this image & we will see how sharp it is tomorrow 12z 120

Edited November 3, 2019 by Steve Murr

[BlueHedgehog074]

Not really much change on the updated 8 to 14 day NOAA/CPC 500mb anomaly chart tonight (which probably was expected). Lower than average heights to the South of the UK with some above average heights East and North-East of Greenland towards Scandinavia. Lower than average heights also to the West of Greenland towards Northern, Central and Eastern Canada, promoting low pressure towards the Western area of the Northern Atlantic. The chart continues to also show a mean, slack, upper flow between the West and North-West over the UK, but a chance it would likely stay rather chilly probably still with Low Pressure areas getting to the South of the UK at times.

Climate Prediction Center - 8-14 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

Yesterday’s chart below:

[feb1991blizzard]

12 minutes ago, Steve Murr said:

Just before the 18z gets going there seems to be a window. appearing about the 140 Mark ( Sat ) where the approaching atlantic ( on its NW > SE Axis ) slides into colder air embedded over NW England & Scotland- 

This highlights some wintry potential- I haven't got the ECM partial thickness however using Meteociel & the 1000HPA contour the 500 Thickness through Scotland is ~532 DAM so certainly >200-300M would be the line.

 

North Wales North is the cut off.

 

Also the current trajectory isnt that acute however as we know when we get these tilted axis they normally sharpen up as we get closer to T0 ( modifications in the 48 - 72 timeline always seem to make them more acute )

NB ECM 2 days ago V tonights 72 ( first ) - The new chart at day 3 is sharper & introduces less milder flow ahead -

 

We now take tonights ECM 144

Remember this image & we will see how sharp it is tomorrow 12z 120

 

Already sharper Atlantic troughing on the 18z at 114 than on the 12z GFS run.

 

Ok its not the same trough you are talking about, the one you mean is around Newfoundland at that point, but it illustrates your point.

[SMU]

132 -138

 

[feb1991blizzard]

Not sure what to make of the 18z yet, looks different.

[Allseasons-Si]

12 minutes ago, feb1991blizzard said:

Not sure what to make of the 18z yet, looks different.

It prob would be better than the 12z at this juncture,the low is some few hundred miles further southeast but better heights into Greenland

18z v 12z 

it's a wetter scenario but it's the NH profile i am looking at,lets see what follows.

Edited November 3, 2019 by Allseasons-si

[ICE COLD]

T222 on the 18z and looking peachy

[feb1991blizzard]

1 minute ago, Allseasons-si said:

It prob would be better than the 12z at this juncture,the low is some few hundred miles further southeast.

18z v 12z 

lets see what follows.

problem with the 18z is the kink in the isobars over scandi at 222, it means the cold cannot reach us, you need a straight long fetch without bends.

[Tim Bland]

Imagine it were January Let’s hope for a winter of repeating patterns ... 

[feb1991blizzard]

Could still be a decent FI but its fraught with pitfalls.

[Allseasons-Si]

3 minutes ago, feb1991blizzard said:

problem with the 18z is the kink in the isobars over scandi at 222, it means the cold cannot reach us, you need a straight long fetch without bends.

There is pretty much always a kink in the isobars there due to the geometry of the mountain range...i think! 

[Tim Bland]

Fairly consistent runs from the GFS for the overall pattern if you compare 240hrs from 12z & 18z...

[tight isobar]

Just now, Allseasons-si said:

There is pretty much always a kink in the isobars there due to the geometry of the mountain range...i think! 

Indeed..and that a minor concern to say the least..such ring micro scale geographical-dynamics are fraught....

 

Anyway nice oscillation via 18z..

With YET again..

Some cracking n-hem graphics on show!

[January Snowstorm]

The gfs is certainly bullish about a significant cold spell in 10 days time. Would be the first decent Nov cold spell since 2010 if it were to come off.....

I must say I found last Winter exhausting chasing cold spells that remained beyond reach. We deserve a bit of luck this year!!

[feb1991blizzard]

11 minutes ago, Allseasons-si said:

There is pretty much always a kink in the isobars there due to the geometry of the mountain range...i think! 

I wonder if that is why shortwaves always develop and cut off the flow and prevent a really snowy North Easterly flow.

[Allseasons-Si]

1 minute ago, feb1991blizzard said:

I wonder if that is why shortwaves always develop and cut off the flow and prevent a really snowy North Easterly flow.

Could be,we need a flow from the east south of that range similar to what the 12z showed,that would be perfect.

[ICE COLD]

It’s gonna have another go on the 18z . 

[ICE COLD]

Now is this the start of what some are predicting? SSW ??? 

[swfc]

12 minutes ago, ICE COLD said:

It’s gonna have another go on the 18z . 

Not a bad run tbh.pitty the 850s arnt great but a great nhp

Edited November 3, 2019 by swfc

[Jordan S]

Hey  been a very busy day so haven't looked on this much but certainly got quite impressive charts spewing out for fi with great posts as always.  short term Looking very wet for Eastern Scotland for most of tomorrow couple of inches accumulating if arpege's correct.

although Icon is lower with amounts..

A signal for more high pressure over Scandinavia but I guess its a while off and subject for variation from model output a very interesting GFS update tonight for the extended range I guess just eye candy at that range...although not particularly cold at that point. It's the bigger picture that's more of note. 

Gfs ensembles for 12z as can't get the 18z looks very unsettled for the most part still but colder than average for a while? Then a big spread highlighting small differences in the overall pattern making a big difference to temperatures. 

The next ten days accumulated rainfall from the Gfs sums up the next week or so nicely one word WET. 

Edited November 3, 2019 by jordan smith

[feb1991blizzard]

GEFS another upgrade, advertising even more PV disruption than any suite this season, some near Beasts with remarkable uppers practically on our doorstep,

[ICE COLD]

3 minutes ago, feb1991blizzard said:

GEFS another upgrade, advertising even more PV disruption than any suite this season, some near Beasts with remarkable uppers practically on our doorstep,

What do you think to that warming showing towards the end feb ? It was getting stronger towards the end . Strongest one I’ve seen yet . 

[ITSY]

The state of the northern hemisphere is... unusual !

[Ali1977]

Not really worked out temps wise this run, but once again the NH PV hasn’t got it’s act together. There are also -32 uppers into Western Russia, with poss -40c ground temps - surely that’s impressive in mid Nov. Few tweaks in T300 below and that would be coming our way. GEFS May have some stockers!! 
 

edit : A few good GEFS but not as many as yesterday. Over to the ECM

Edited November 4, 2019 by Ali1977