Model output discussion - 1st December onwards

[January Snowstorm]

Ecm 192 hrs is good!

Surely a decent undercut here.

Raging easterly by 240hrs?

[Frosty.]

14 minutes ago, lorenzo said:

Yes - 2 threads here, Knocker comparing the inter run GEFS, am looking at the W2 impacts and potential for Wave Activity Flux

We need a flux capacitor to get us out of this very mild mushy pattern. 

Edited December 26, 2015 by Frosty.

[Snowman.]

1 minute ago, January Snowstorm said:

Ecm 192 hrs is good!

Surely a decent undercut here.

Raging easterly by 240hrs?

Unlikely the block is too far east. If this was last year with the considerably weaker vortex we would probably be play ball but this year we have a monster that going to need some real manpower to drive it down.

[Snowman.]

T216

While a mess over scandi area lower pressure is finally sinking in europe with the jet on a southerly track.

Edited December 26, 2015 by SN0WM4N

[nick sussex]

Not a bad ECM run, block holds on, lots of cold air to the east. A full blown easterly might not be on the cards yet but frontal snow if trough disruption is favourable isn't out of the question for the UK.

I should add in most cases where things have gone wrong its the sinking Scandi high that's been the issue however we don't see the models wanting to do this. If the block holds we might get a few chances.

 

Edited December 26, 2015 by nick sussex

[knocker]

18 minutes ago, lorenzo said:

Yes - 2 threads here, Knocker comparing the inter run GEFS, am looking at the W2 impacts and potential for Wave Activity Flux, more so having seen the Polar Cap Temp forecast just posted in the strat. thread. Sorry, to confuse. Simply put, the projecting WAA and trop. blocks are of interest in taking down the vortex. The enhanced blocking outlook via the mean chart illustrated earlier timing nicely with the fade out of the vortex intensification period. 

Cheers Lorenzo I hadn't realised you had posted and I appreciate this is of interest vis the vortex. Apparently similar WAA occurred in 97/98 but I know not what  the outcome was.

[Eskimo]

A fantastic ECM if you love snow in my opinion. An okay ECM if you prefer prolonged cold. A couple of snow events (marginal on low ground) according to that run. 

 

[Snowman.]

Nice end to the run heights backing west and the P/V over greenland considerably weaker with troughs sliding SE keeping the block up. More realistic that those easterlies by day 10.

Edited December 26, 2015 by SN0WM4N

[knocker]

Now this looks remarkably like the GEFS anomaly chart allowing for some poetic license.

Edited December 26, 2015 by knocker

[Richard Taylor]

21 minutes ago, Frosty. said:

We need a flux capacitor to get us out of this very mild mushy pattern. 

Fit it immediately to the De Lorean & take us back to 1962/3!

[Methuselah]

1 minute ago, Richard Taylor said:

Fit it immediately to the De Lorean & take us back to 1962/3!

lol. I was going to enlist a TARDIS!

[A.J]

Model discussion please folks

[NorthYorksWeather]

A lot of scatter after the new year, OP looks to be one of the warmer members, plenty taking a nosedive to cold so will be interesting to see what the 18z shows. Still all to play for snow-wise but certainly not as straightforward as we would like.

[phil nw.]

We are certainly entering a pivitol period in modeling now if we are to see a switch to cold in the heart of Winter.

The current pattern with a developing Scandi block fighting against a rampant Greenland vortex is one of the most fascinating but frustrating setups where we often see a protracted period of several days of a battleground situation before it's resolved.

At this stage we are no nearer a result but what i have noticed from previous times where the block wins is that the sub-tropical ridging builds from the Azores area which is further west than this current pattern.

Compare 2 good easterlies that came from that region and this current pattern.

Notice the Greenland vortex is attacked further west on the historical events so already the building heights are further west and the battleground was west of the UK.Trough disruption was then better placed to extend into S.Europe and advect the cold west towards the UK.some days later.

As a general rule of thumb if we see deep low pressure at the base of the Greenland trough too far east as the ridging builds then it is an uphill battle for a block to stop the Atlantic from there as too much energy is waiting to go north.

I think currently because we start with our block building further east pushing up from N.Africa we are at a disadvatange as the pattern would have to retrogress much further west before we are in the game for cold.

We may well get there down the line with further wavebreaking as this looks like continuing into January putting ongoing pressure on this cold vortex and warming it -as Lorenzo suggested earlier.

Easterlies are never a straightforward event unlike say a northerly toppler and i think we need more than 1 attempt if it is to happen.Even the successful ones often had a couple of false starts so as long as we continue to see the vortex pinched by the wave 2 action then we can remain hopeful i reckon.

 

[karyo]

21 minutes ago, knocker said:

Now this looks remarkably like the GEFS anomaly chart allowing for some poetic license.

Very unusual to have a low pressure system over the Cape verde at this time of the year.

[nick sussex]

You can see from Phil's post that we don't need the PV obliterated to get cold. I think sometimes theres too much emphasis on only thinking cold is possible if the PV is blown to pieces. A raging PV is fine as long as its far enough away and orientated in a favourable manner.

[Man With Beard]

That's as much as can hope for from the ECM. Heights to the NE and heights lowered through central Europe by T168. The place where the Atlantic and the European cold pool collide, well that's a real lottery this far out. Somewhere between tonight's GFS and ECM could be very interesting after T168

[phil nw.]

3 minutes ago, nick sussex said:

You can see from Phil's post that we don't need the PV obliterated to get cold. I think sometimes theres too much emphasis on only thinking cold is possible if the PV is blown to pieces. A raging PV is fine as long as its far enough away and orientated in a favourable manner.

Absolutely Nick.

How could i have forgotten 1987 in my previous post.

Note again the slither of heights building into the pole from the Azores area,everything starts further west.The deep cold already has a start over E.Europe.

[winterof79]

24 minutes ago, phil nw. said:

Absolutely Nick.

How could i have forgotten 1987 in my previous post.

Note again the slither of heights building into the pole from the Azores area,everything starts further west.The deep cold already has a start over E.Europe.

I  was in Germany then and can confirm extreme cold during the day and frost bite an issue.

[Blake]

Even the JMA picking something up now. Yesterday's 12z for next Sunday...

Today's 12z for next Sunday...

 

Plenty of rain but differences a plenty over Scandi...

 

[ANYWEATHER]

Good Boxing Day everyone! No one can say that the outlook is boring! The Atlantic onslaught continues, with concern during the middle of next week with a major storm system , perhaps another one for New Year and then some teasing synoptics for real Winter to begin at the start of the New Year. Welcome to the Uk Weather,,,,!

[knocker]

Interesting evolution from tonight's ecm anomalies. At T120 a hugely amplified pattern with strong ridging north through Finland and the trough to the west digging way south giving a strong SW flow over the UK and some unpleasant weather. The vortex doing a little fandago over N. Canada. But by T240 all has changed. The ridge to east has morphed into an HP cell way east over Russia and the trough to the west has realigned and is now negatively tilted through the North Sea into eastern Europe. This veers the flow westerly but we are looking at fairly unsettled weather albeit not quite so wet and windy.

Looking ahead to T360 there is a shallow trough Greenland and another trough to the east running south from the Baltic south to Turkey so still westerly flow over the UK. THe 200mb chart has the main jet running into the UK and down the trough and no indication of upper blocking. In fact there is no suggestion at all of blocking developing to the E/NE

Edited December 26, 2015 by knocker

[OldMetMan]

Hi everyone, I hope you all enjoyed your Christmas.

I have been watching the models well struggle basically, with the developing HP over Scandinavia, coming up with a variety of solutions. It seems pretty likely that the HP will develop, although it is a bit far E, as is the associated upper high, from the point of view of the UK. Given the remarkable persistence of the S to SW flow and the resulting insanely high temperatures we've been getting for the best part of the last 2 months (I have had EIGHT days this month with temps over 15C), I cannot see how this can last much longer, without the upper pattern somehow shifting, most likely retrogressing. The first appearance of really cold air over E Europe has got to mean a change in pattern as I see it.

There is still too much energy in the Atlantic systems I think for anything immediate to happen, but if as I suggested above, should the pattern shifts W, and should the upper high take up position to our N, then we may at last have an opportunity for something more seasonal to spread from the Continent, 

I like the look of the significant upper trough now across the US, and still amplifying it seems. It might encourage similar amplitudes downstream. But again, the positioning of the upper pattern will be crucial.

Let's see how the HP holds its ground against the vigorous Atlantic onslaughts over the coming days. Winter may at last arrive!

Edited December 26, 2015 by OldMetMan

[tinybill]

just looked hoping to see some rest from this horrible weather from now to deep into fantasy world   i just cant see any letup   to the flooding hitting  the  u.k. at the  moment

 

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=6

 

 

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

[radiohead]

Just now, tinybill said:

just looked hoping to see some rest from this horrible weather from now to deep into fantasy world   i just cant see any letup   to the flooding hitting  the  u.k. at the  moment

 

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=6

 

 

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

I'm quite worried about a battleground setup going the wrong way, with slow moving or stalled lows dumping rain while pushing up against a block. It's something I've seen in FI on some of the models recently and I'm really hoping it doesn't happen....