Model Output Discussion - 23rd Jan - 12z onwards

[seaside 60]

Would say Feb 91 or Dec 10.

If it was one of the people who craves for mild options one of those Feb's where it got to 16/18c lol..

[Timmytour]

Here's n Atlantic Dog called Toppler sniffing the UK in Feb 1983.

We did quite well for snow around about that time as I recall though overall the month was pretty dry, although cold.

Wonder if Toppler's coming for another sniff this year?

[Eugene]

Noticeable improvement on GFS 06Z with HP moving over us next weekend keeping us cold and frosty, i think thats the most likely solution.

[Chris Wsm]

I hope the Navgem is on to something , The Cold spell never ends .. 

 

[Geordiesnow]

Noticeable improvement on GFS 06Z with HP moving over us next weekend keeping us cold and frosty, i think thats the most likely solution.

 

Why?

 

Its an evolution that is likely too happen but just how quickly will the high topple in, UKMO/ECM suggests this could happen quicker than first thought which means the Northerly/Easterly flow will get less and less, the GFS at least drags the situation out a little bit more.

[winterof79]

image.jpg

Small experiment

Anyone care to guess what conditions were like on the ground in the uk and what pattern followed this chart?

Isn't that identical to UKMO 72z chart BA ?

[chionomaniac]

We have seen the GFS pattern currently modelled at day 10 recur this winter - but only at day 10 on the GFS charts. By day 5 there has been far more amplification in the flow and I wouldn't be surprised to see the same modeled again.

 

Still waiting to see what MJO signal emerges - but the (weak) trend is heading towards phase8 with the GFS and ECM - a total antithesis to where the day 10 models are headed. Still I expect the pattern to re amplify.

 

In the meantime, another surprise snowfall here today and with heights still low for the next 3-4 days who knows what will crop up in the colder flow.

[Cloud 10]

image.jpg

Small experiment

Anyone care to guess what conditions were like on the ground in the uk and what pattern followed this chart?

 

Must try harder.

 

Isn't that identical to UKMO 72z chart BA ?

 

 

Ding Ding!  we have a winner.

 

[bluearmy]

Yep - that chart within 72 hours and yet we will have no lying snow away from elevation and over Scotland and the far n of England in places. and to follow, a slowly sinking ridge - apparently. can take too much from one chart in isolation is the lesson.

Tbf, you couldn't see the vortex or the upstream. if upstream isn't modelled well then neither will the Atlantic be.

[seaside 60]

Must try harder.

 

 

 

Ding Ding!  we have a winner.

 

UW72-21.gif

Simple question, on that chart, what is stopping that low in the Atlantic sliding underneath the high and propping it up.

It seems to have a negative nose edging se wards.

[shotski]

Yep - that chart within 72 hours and yet we will have no lying snow away from elevation and over Scotland and the far n of England in places. and to follow, a slowly sinking ridge - apparently. can take too much from one chart in isolation is the lesson.

Tbf, you couldn't see the vortex or the upstream. if upstream isn't modelled well then neither will the Atlantic be.

No lying snow BA, are you sure about that comment.

[bluearmy]

No lying snow BA, are you sure about that comment.

let me know tues night. not expecting much apart from my caveats

[shotski]

Ok BA, prepare to eat pie that is humble :=)

[Cloud 10]

Simple question, on that chart, what is stopping that low in the Atlantic sliding underneath the high and propping it up.

It seems to have a negative nose edging se wards.

 

Easier to show on the GFS for around the same time.

 

 

 

Basically a small streak of jet "energy" tries to undercut the high,hence the small LP,but sadly it is not strong or sustained enough to prop it up.

[bluearmy]

Ok BA, prepare to eat pie that is humble :=)

Will be delighted for those who are beneficiaries

the week 2 gefs trending more strongly towards the ECM view of things with the wintry easterly members dropping away.

[492]

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

8- 10 day 500mb contour charts show a tendency for blocking across parts of the N hemisphere. The low heights shown to be extending westwards to the south of the UK  result in the Azores high being displaced slightly further to the north with ridging to the NE. The southern half of the UK looks to be at increasing risk of cold as it comes more under the influence of the developing vortex to the south. 

[seaside 60]

Easier to show on the GFS for around the same time.

 

gfs-0-66.pnggfs-5-60.png

 

 

Basically a small streak of jet "energy" tries to undercut the high,hence the small LP,but sadly it is not strong or sustained enough to prop it up.

Thanks for that, shame the UKMO had a better looking profile for it to go under.

One can always hope.

[nick sussex]

Putting aside prospects for next weekend the ECM spreads do show some leeway with a possible easterly, not so much in terms of upper air temperatures but more in terms of SLP.

 

 

Theres very good agreement on high pressure to the nw and low pressure over northern Italy, the uncertainty is the strength of the flow into the UK, more especially towards the south and se and the SLP.

 

At that range corrections north/south are possible a hundred miles either way will either see a mainly dry east/ne flow or one with a bit more convection potential.

 

 

[Eugene]

Noticeable improvement on GFS 06Z with HP moving over us next weekend keeping us cold and frosty, i think thats the most likely solution.

 

 

Good support for GFS 06Z OP on GFS 06Z ensembles for it turning anticyclonic week 2.

[summer blizzard]

Yup. We get a whole one front moving across the UK before the high rebuilds on the 6z. Some absolutely lovely April onward synoptics. 

 

[SE Blizzards]

Good support for GFS 06Z OP on GFS 06Z ensembles for it turning anticyclonic week 2.

 

Yes, quite a few members in FI showing HP close too, or around the UK, a regular occurrence as of late. Higher upper temps for sure, but cold at the surface.

 

P15 my favourite

 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=15&ech=372&mode=0&carte=0

[weather eater]

Yes, quite a few members in FI showing HP close too, or around the UK, a regular occurrence as of late. Higher upper temps for sure, but cold at the surface.

 

P15 my favourite

 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=15&ech=372&mode=0&carte=0

Amazing because that's what the OPs have been showing in the main for days now, give me the OPs any day over the ensembles they are as much use as a marzipan crowbar most of the time.

[seaside 60]

On reading what some of the more professional peoples on here have said.

I cant really understand why some people seem to think its going to be zonal type weather, just because of  a few cherry picked charts..
February being the least zonal of the winter months and with lots of background signs for it to be at least settled and cold for many of us, this seems to be on a lot of the further outlook charts.

[nick sussex]

The UKMO suggest that the MJO won't be very influential however a few weeks back I'm sure they said the same thing and then put down that colder interlude to the high amplitude phase 6.Which both the ECM and UKMO wanted to take into the COD before phase 7 against the GEFS.

 

What transpired was that the UKMO and ECM MJO forecasts were proven wrong, what verified was a blend of the GEFS and GEFS bias corrected. Until we know what the MJO will do then I'd be wary of the outputs. We have another divergence of opinion between the GEFS and the others so that will take a few days to sort out as we won't get any updates now till Monday.

Edited January 31, 2015 by nick sussex

[phil nw.]

I would give it a couple more days wrt the evolution from next week end.

A number of Op runs have trended milder against the ensembles beyond day 6 and with the cold spell already extended to the end of the coming week it shows the pattern is not regaining any real mobility yet.

 

A look at the GFS 00z ens 2m temp.graph for Warks. and the combined London suite shows what i mean

 

 

there is certainly no real push to sweep away the cold block that will establish early next week.A look at the day 6 850hPa temp. mean charts see the UK still in the cold with impressive mean -8C uppers still over the se.

 

 

We can't obviously ignore the strong signal for a mid-latitude block across the UK locale from next week end. Although this would cut off the cold feed of upper air there is every chance a cold surface would continue beyond and this is what the 2mtr ens temperatures  indicate.

Whilst the low heights remain over S.Europe it prevents the block sinking and an early return of a mobile westerly flow across the UK therefore remains unlikely.

I think we can afford some optimism in future cold prospects for now, indeed if we regain further amplification in the flow we could see the block ridging further north.

In the meantime it will get colder in the next few days as the true Arctic air filters south with some hard night frosts and with the prospect of snow showers in some northern and eastern districts.