Model output discussion - 1st December onwards

[feb1991blizzard]

^^

 

Its very decent at 144.

[northwestsnow]

2 minutes ago, feb1991blizzard said:

^^

 

Its very decent at 144.

Yes i think we could have an opportunity for some flakes of the snow next week feb1991, time to dust down the lampost goggles perhaps

[That ECM]

8 minutes ago, northwestsnow said:

Hmmm no posts on ecm? I guess it saves me bothering to look

http://www.wetterzentrale.de/pics/Recm1201.html

Looks OK at 120-

and at 144

http://www.wetterzentrale.de/pics/Recm1441.html

Suprised no one has commented, looks like an opportunity for snow across scotland and the north.

The ukmo at t144 looks good for the north. Ukmo tends not to get so much commentary due to no 850 temps and the fact it stops at t 144 but for me its very interesting. Poss height rises to the west and north, if only the two could hook up!!!

[Iceberg]

I know it's a gefs frame, however the sub 910mb low, probably 907mb or so' would be clearly record breaking and utterly extraordinary. 

Unlikely to happen, I am sure I don't need to say, but of more importance is the build up of energy, the transfer of energy from the tropics to the poles is as large if not larger than at any time I have ever seen in my 15 years of model watching. The variation in the gefs members supports this.. This level of Energy that can transfer up to 100-200mb within 48 hrs makes any reliance on models hard to fathom. I actually quite enjoy looking at the models even at t144 with the knowledge that I don't think they will be particularly accurate..

Happy new year 

[Essex snowman]

Morning all are the models showing any cold at all for us in east of England thanks guys and girls 

[northwestsnow]

Just now, Essex snowman said:

Morning all are the models showing any cold at all for us in east of England thanks guys and girls 

Good morning, looks like there is some potential for some wintry weather across parts of the north and into scotland next week but even here i would suggest elevation will be important.Forlow lying England certainly south of the midlands i would suggest little prospect of any snow,i could be wrong but thats my take on the morning runs.

[IDO]

The three main models all in agreement at T192 for the Atlantic to send a vortex of low pressure into the UK in a cool (seasonal) flow. That sits over the UK and begins to ease away around D10; D8 comparisson charts: 

     

So as expected no easterly and any disruption is short term on all models. Maybe some transient white stuff to favoured places in the north. As expected the wave that generated the HLB cannot sustain it in a mobile background and although initially formed over Scandi the block is slowly pushed East, then SE and by D11 it dissipates into other systems.

From D11 the trop PV is disorganised, recovering from the wave 2 attack and as it recovers(??) how the long wave pattern sets up from this re-jig is anyone's guess. It seems logical the Atlantic will be quieter for a while, so room for maybe the Azores to gain some ground NE towards the UK? However the GEFS mean suggests the normal will be resumed, as by D16 a trop vortex is settling down over the NW:

Confidence at this range is very low so just watching for trends at the moment. Hopefully those 3-5 days when the chunk of vortex sits over the UK will just fill and wont generate satellite lows, so maybe we will only get showers rather than more rainfall. The upper flow looks stable so frontal rain will not be an issue if we don't get lows forming within the vortex.

As far as cold and snow is concerned, another missed opportunity for the UK, they are rare this Winter (any winter) so we need to get lucky and again we have the action not far too our east. The search for another cold spell from mid-late Jan is the next target.

 

Edited December 31, 2015 by IDO

[northwestsnow]

I would imagine ecm has a brief window where the uppers will allow for snow to fall, mainly north of the midlands.

http://www.wetterzentrale.de/pics/Recm1442.html

Edited December 31, 2015 by northwestsnow

[SMU]

Let me just correct you IDO

The 3 main models dont show that as the UKMO indicates a different scenario evolving from 144 ( same as NAVGEM 00z )

& seeing as the UKMO has better varification than the GEM & GFS we cannot assume this will be the case even though its a possibility-

If the atlantic ridge gets thrown like the UKMO & NAVGEM propose then there will be no deep low- its happened many times before....

as for using the day 16 ENS mean - about as pointless as it was when you posted them last year & the year before that

The day 10 ECM & GFS means 10 days ago didnt have a whiff of a high pressure block - so the 16 day is as pointless as a chocolate firegard-

 

S

Edited December 31, 2015 by THE CHOSEN ONE

[northwestsnow]

1 minute ago, THE CHOSEN ONE said:

Let me just correct you IDO

The 3 main models dont show that as the UKMO indicates a different scenario evolving from 144 ( same as NAVGEM 00z )

& seeing as the UKMO has better varification than the GEM & GFS we cannot assume this will be the case even though its a possibility-

If the atlantic ridge gets thrown like the UKMO & NAVGEM propose then there will be no deep low- its happened many times before....

S

http://www.wetterzentrale.de/pics/Rukm1441.html

Does look different to the others  as you say, the low south west of iceland looks primed to disrupt.

[That ECM]

1 minute ago, THE CHOSEN ONE said:

Let me just correct you IDO

The 3 main models dont show that as the UKMO indicates a different scenario evolving from 144 ( same as NAVGEM 00z )

& seeing as the UKMO has better varification than the GEM & GFS we cannot assume this will be the case even though its a possibility-

If the atlantic ridge gets thrown like the UKMO & NAVGEM propose then there will be no deep low- its happened many times before....

S

Agreed and even if it doesn't, the north and the NE could have a few interesting days. IDO has looked at it from a IMBY position I feel.

[fergieweather]

6 minutes ago, THE CHOSEN ONE said:

Let me just correct you IDO

The 3 main models dont show that as the UKMO indicates a different scenario evolving from 144 ( same as NAVGEM 00z )

& seeing as the UKMO has better varification than the GEM & GFS we cannot assume this will be the case even though its a possibility-

If the atlantic ridge gets thrown like the UKMO & NAVGEM propose then there will be no deep low- its happened many times before....

as for using the day 16 ENS mean - about as pointless as it was when you posted them last year & the year before that

The day 10 ECM & GFS means 10 days ago didnt have a whiff of a high pressure block - so the 16 day is as pointless as a chocolate firegard-

 

S

...albeit as a nod to GFS and with some EC-EPS support, the 00z UKMO-GM has been modified to re-insert the low latitude low running to S of UK. So raw model not representative of *current* UKMO forecast but confidence is of course low.

[tinybill]

i  know  its a long way off if this happens there could be problems!!!

[IDO]

10 minutes ago, THE CHOSEN ONE said:

Let me just correct you IDO

The 3 main models dont show that as the UKMO indicates a different scenario evolving from 144 ( same as NAVGEM 00z )

& seeing as the UKMO has better varification than the GEM & GFS we cannot assume this will be the case even though its a possibility-

If the atlantic ridge gets thrown like the UKMO & NAVGEM propose then there will be no deep low- its happened many times before....

as for using the day 16 ENS mean - about as pointless as it was when you posted them last year & the year before that

The day 10 ECM & GFS means 10 days ago didnt have a whiff of a high pressure block - so the 16 day is as pointless as a chocolate firegard-

 

S

Fair enough with the UKMO, but I have seen that in scenarios like this the UKMO usually plays catch up and is rarely ahead of the game. Of course every dog has its day and this time the UKMO may be right, but I am not too hopeful. 

As for means I did say that they should be used as trends to possible long wave patterns and statistically their verification is the best option compared to op runs.  

Edited December 31, 2015 by IDO

[West is Best]

29 minutes ago, IDO said:

The three main models all in agreement at T192 for the Atlantic to send a vortex of low pressure into the UK in a cool (seasonal) flow. That sits over the UK and begins to ease away around D10; D8 comparisson charts:      

So as expected no easterly and any disruption is short term on all models. The search for another cold spell from mid-late Jan is the next target.

 

 

The three main models aren't in agreement about anything, especially beyond T96 let alone T192. UKMO has enormous potential, as does ECM in the short term. Even the GFS in short term is a considerable improvement on this time 24 hours ago. All the models have been flip flopping as they try to cope not only with shortwave patterns and amplification but the extent and position of the Scandinavian aka Scrussian high. Anyone coming on here claiming sage-like knowledge about the patterns 5-10 days hence, be that for cold or mild, is using shamanism more than science.

Edited December 31, 2015 by Paul

[nick sussex]

Rather than getting more agreement this morning for the period upto T144hrs things seem to be going in the opposite direction.

The main difference is the way the models deal with the upstream pattern over the ne USA, again we're dealing with the amplification or lack of and the dig of cold into the ne USA.

Because the UKMO which now supports the NAVGEM is more amplified this helps to extend a ridge from the Azores high, this allows the UK low to clear ese.

Haven't had a chance yet to catch up with the USA state forecasts but these should prove interesting in terms of model preferences for that ne part of the USA.

[northwestsnow]

4 minutes ago, fergieweather said:

...albeit as a nod to GFS and with some EC-EPS support, the 00z UKMO-GM has been modified to re-insert the low latitude low running to S of UK. So raw model not representative of *current* UKMO forecast but confidence is of course low.

Bugger. Not what majority wanted to hear Ian.

Thanks all the same though

 

Edited December 31, 2015 by northwestsnow

[Severe Siberian icy blast]

5 minutes ago, THE CHOSEN ONE said:

Let me just correct you IDO

The 3 main models dont show that as the UKMO indicates a different scenario evolving from 144 ( same as NAVGEM 00z )

& seeing as the UKMO has better varification than the GEM & GFS we cannot assume this will be the case even though its a possibility-

If the atlantic ridge gets thrown like the UKMO & NAVGEM propose then there will be no deep low- its happened many times before....

S

Absolutely.  I guess the UKMO wasn't mentioned as it don't go that far . But is the gfs and gem really even worth disecting at 192hrs ?  His post is so misleading infact it normally is because there is no way you can accurately make a forecast that far out by using the means . The fact we have trough disruption regularly between now and t144 then surely that's area we need to focus on ? The ecm ,UKMO and gfs to an extent have all moved significantly closer to a colder spell with a continental influence with snow events a possibility next week . We no how all models struggle with HLB and the gfs is notorious for blowing up the atlantic . 

This morning there is much better charts to look through if your hoping for colder weather next week . 

[TSNWK]

4 minutes ago, fergieweather said:

...albeit as a nod to GFS and with some EC-EPS support, the 00z UKMO-GM has been modified to re-insert the low latitude low running to S of UK. So raw model not representative of *current* UKMO forecast but confidence is of course low.

Oh! Mr ian you are such a spoil sport  Boo.........

[West is Best]

6 minutes ago, fergieweather said:

 confidence is of course low.

 

Bear in mind that the 18z GFS had an even better run than your modified 0z UKMO.

We're in a pattern change. It's not a time for the faint-hearted.

[fergieweather]

3 minutes ago, northwestsnow said:

Bugger. Not what majority wanted to hear Ian.

 

Yes but given raw model lost the feature, we can't be too prescriptive yet on how it'll unfold.

[SMU]

Thanks Ian

Modified to the consensus at the moment by the UKmet ... However the senior forecaster omitted the NAVGEM from his favourites - ive emailed him to include that into the probability weighting

Happy NY

it would help if yiu could add how many EPS members at 144 are in the UKMO camp...

S

Edited December 31, 2015 by THE CHOSEN ONE

[IDO]

14 minutes ago, West is Best said:

 

The three main models aren't in agreement about anything, especially beyond T96 let alone T192. UKMO has enormous potential, as does ECM in the short term. Even the GFS in short term is a considerable improvement on this time 24 hours ago. All the models have been flip flopping as they try to cope not only with shortwave patterns but the extent and position of the Scandinavian aka Scrussian high. Anyone coming on here claiming sage-like knowledge about the patterns 5-10 days hence, be that for cold or mild, is using shamanism more than science.

That is semantics, yes differences between GEM, GFS and ECM in the short term but if they all agree at D7-8 with a burst of the Atlantic barging through, any good work in the intervening period is nullified. I really do not see the Atlantic being stopped even with the initial trough disruption from the undercut, this has been de facto the outcome from the GEFS for days. Anyway just my opinion 

D10 GEFS: 

Edited December 31, 2015 by Polar Maritime

[northwestsnow]

1 minute ago, fergieweather said:

Yes but given raw model lost the feature, we can't be too prescriptive yet on how it'll unfold.

Thanks again for your kind input, its greatly appreciated, weather geeks of the world unite

 

[fergieweather]

4 minutes ago, THE CHOSEN ONE said:

Thanks Ian

Modified to the consensus at the moment by the UKmet ... However the senior forecaster omitted the NAVGEM from his favourites - ive emailed him to include that into the probability weighting

Happy NY

S

Ha ha. That's one thing that won't ever happen...!!