Into February: Forecast and Model Discussion commentary

[Mcconnor8]

 Mike Poole Yep the AI still looks like a good Easterly from Day 10 onwards till the end of the run as well, very much in the game but need to start seeing some consistency among all the models soon.

[Mike Poole]

28 minutes ago, Beanz said:

How’s the LRF looking for a warm spring? 

I’d say a good deal worse than it was a couple of days ago!  On the grounds that the odds for a late winter SSW have seemingly been slashed - as you can see from the ECM 46 10 hPa zonal winds plot, many members now gunning for it:

[Mcconnor8]

 Mike Poole Why is it we can only seem to get a SSW in Late Feb recently just in time to ruin Spring 

[Met4Cast]

I’m not really seeing anything from the EPS to suggest anything other than a very brief easterly before forcing from the NW blows it away; 

192-240

The extended clusters are even worse with overwhelming Atlantic support;

Although interestingly cluster 1 does appear to go for an Atlantic ridge of sorts, albeit too far west to “deliver the goods” on this run. 

I’d place the likelihood of a cold easterly now <5% unfortunately, a definite step backwards across the models this morning. 

None of these charts scream bitter cold easterly or growing momentum for a proper easterly, not overly surprising given the current background conditions. 

A third failed easterly from the models in a row? Maybe.

Edited January 30 by Met4Cast

[Met4Cast]

 northwestsnow

Unfortunately I think this is the beginning of the end; 

The best the mean can do is a brief southeasterly followed by the Atlantic moving in. There’s just too eastwards energy. 

[Beanz]

 Mike Poole lovely, so the worst of both worlds then.  Yuk. 

[Mcconnor8]

AI looks great from Day 9 onwards, if/when it backs down I'll concede defeat but as it is the best model at picking out patterns in FI I will retain some hope at least for now.

@Met4Cast I would give us a 15-20% chance of the Easterly, but at an unknown depth of cold.

Edited January 30 by Mcconnor8

[Jacob]

ICON 6z looks like a downgrade at 114h.The WWA is going too far east and south

Edited January 30 by Jacob

[Mcconnor8]

 Jacob It's the 2nd push of heights at Day 6-7 which matter more for the Easterly so I wouldn't draw much from an ICON run that goes to Day 5

[Dennis]

Polarvortex fun

Edited January 30 by Dennis

[nick sussex]

As the saying goes as one door shuts another gets slammed in your face ! 
 

The Siberian high is often mutton dressed as lamb . It looks great initially then rarely does it manage the very long journey westwards .

It’s for this reason that for the UK a smaller high over Scandi is the better option .

As we can see it’s a struggle to advect any deeper cold west , we have a flabby ridge extension from the mutton high but no low pressure over northern Italy which really is what you need .

So currently the best we might get out of this in the next ten days is a battleground scenario if we can get enough cold west before the Atlantic pushes in . 

A convective easterly is very unlikely and that ship really never left the port .

We live in hope and it’s too early to be drawing concrete conclusions as we head later into February.

 

[Wedgesmakesledges]

As ever to many knee jeek reactions.

GFS 06z I believe looks a fair bet around whats going to happen around 120.

The cold pool is favourably alligned & theres better atlantic amplification 

Theres also less PV interference on the Block over western Norway.

The upper air cold pool at this stage is over Poland crossing into the German Border alligned East to west ( 00z was NE to SW ) 

Should see better results here.

 

[Mcconnor8]

Nicer cold pool in Europe on the 6z compared to 0z, it's an improvement for sure with the pattern shunted West somewhat, but probably not enough yet on this run.

Vortex under significant strain with this pattern you would imagine.

Edited January 30 by Mcconnor8

[nick sussex]

A better orientation to the high here . With more trough disruption as a result .

 

[Wedgesmakesledges]

Much colder at 192 than the 00z all because of the earlier allignment.

Snow flurries arriving at 198- for the NE

- An extra chart people might want to use than never appears here is the Theta E 850 Charts.

For early feb from the continent Sub 10C is the benchmark for snow

If we think this monster block is just going to move over out the way - we havent been paying much attention...

Edited January 30 by Wedgesmakesledges

[Mcconnor8]

 nick sussex Looks closer to the AI 0z which had some nice disruption preventing the Atlantic getting in all the way out to Day 15 and no sign of it at that point either

Edited January 30 by Mcconnor8

[Mike Poole]

GFS 6z turning into a half decent run:

We are only ever the last stop on the train for this easterly, but there are a fair proportion of runs that get it far enough west to bring cold air to the UK.

[Wedgesmakesledges]

GFS mean 120 broadly inline with Operational.

The area to focus on over the next 48 hours isnt probably the UK in isolation but how the allignment of the low over Germany is forecast on the 12Z Sat T66 chart. 

Also the amplitude of the next wave out the states at a similar timeframe. 

[Don]

As I said the other day, it's particularly frustrating at the moment because it looks like the pattern really wants to go cold, but is thwarted by unfavorable background signals?  If only they were slightly more favorable, we really could have been in the game?!

[bluearmy]

 Met4Cast a glass half full assessment would be that blocking to our east is often underestimated once in situ so if we can develop a nw European cold pool whilst the block builds then a decent attack by the Atlantic lw trough could well split and if enough energy undercuts then advection of the cold further to our east is more likely to follow. 

a glass half empty assessment is that we’ll enjoy the chase and then it will end up with a degrading occlusion that delivers a few bits of snow before the Atlantic rolls through ……

@Mike Poole re the strat - the eps mean was less stretched by days 13/15 than recently and much more ‘Greenland centric’.  If the 46 is on that page then expect less runs to reverse later (although it no longer uses the eps day 15 as starting data). 
let’s hope that the this is down to a suite which was amplified in different areas rather than an evolution in a different direction.  The Canadian/greeny vortex certainly looks more potent in a fortnight than it did yesterday. 

Edited January 30 by bluearmy

[MJB]

 Wedgesmakesledges

Agreed , Looks a strong block to me 

[Dennis]

Polarvortex split GFS6z

 

[IDO]

The nascent changes around the mid-February stretch are becoming more evident from the NH perspective. The 06z, for instance in FI:

 

With the upstream blocking translating to the tPV over to our NW being weakened, promoting the block to our east to build and sustain. It's a shame that it started too far east, but with a good orientation post-D7, we can get some cold uppers in situ reinforced from the SE and NW during the ebb and flow of forces. 

So, the optimism of changed mid-February remains, but the usual caveats.

[Met4Cast]

The mean doesn’t look supportive of the det to me with the det already pushing into outlier territory by 6th February. 

I suspect it’ll be largely on it’s own, no real shift in momentum from the GEFS. 

Edited January 30 by Met4Cast

[Mcconnor8]

 Met4Cast The fact the operational was similar to the AI means it has a decent chance imo, I rate the AI at Day 8-10 far above every other model

Edited January 30 by Mcconnor8