314 replies to this topic

[Yorkshiresnows]

Well, I can't help thinking we are seeing positive signs tonight. Can't help feeling an Easterly is on the cards down the line.

Strat looks good. PV on the wain (from background signals), more amplification from the GFS.

Just need a little more correction and we're there !

Y.S

[nick sussex]

All the model output so far has lots of potential, the GEM is an upgrade from this morning, the NOGAPS gives a UK wide snow event with a shortwave heading south. The GFS is close to very good and the UKMO shows the PV elongated and heading away.

Overall the best outputs of the winter so far because these are at 144hrs and we're not looking into FI for signs of a snowflake. We await the ECM to see what that has to say.

[Buzzit]

The dartboard low sitting over Europe at +120 appears to be sucking the life out of any chance of a decent cold hit, a similar evolution to the UKMO, including a pesky jetstream that suddenly wants to go on a package holiday tour across Europe.

[Anonymous21]

The PIT, on 16 January 2012 - 16:56 , said:

Aaah a deep FI tease you get the feeding frenzy going tonight. Close but no cigar. In fact I'm going to complain to the royal society for the prevention of cruilty to snow lovers. The really cold air just sitting to the east in deep FI is really cruel. Just outside the reliable time which seems to be going unnoticed is a possible breezy period for North eatern and eastern coastal areas this weekend. So you get some good seas to photograph if not any snow.

Indeed, you can't help but get the feeling from looking at this run that just if only the pattern was shunted a little further west.

Anyway let's see what the ECM brings.

Edited by Anonymous21, 16 January 2012 - 17:36 .

[Zakos]

Frosty039, on 16 January 2012 - 17:01 , said:

With the high just to the southwest of the BI, it currently seems unlikely, the gfs 00z was showing milder weather covering the uk next weekend but it has backtracked quite a lot, the ukmo 00z was showing a cold weekend and still is, infact it has upgraded slightly but this is only my view Zakos, these kind of charts have been rare this winter, I can't recall an instance in the last 6 weeks when the pattern has backed west bringing snow risk so we are potentially breaking new ground if it happens.

Its your opinion and I respect that. I wasn't being mean (sorry if I came across that way)

Exactly! This is the pattern change forecast by GP! Thats why we havent seen anything like this is the last 6 weeks. just because it hasnt happened yet doesnt mean its not going to, infact statistically its probably more likely that we do see cold

I do see your point, and were not not going to know for sure for a good while yet with all this uncertainty.

But you cant argue that these are the best charts this winter, and they continue to get better each run (more or less)

[Steve Murr]

Guys a will take a large slice of PTB 1 to go please-

http://modeles.meteo...-1-1-150.png?12

OR 5
http://modeles.meteo...-5-1-162.png?12

OR 7
http://modeles.meteo...-7-1-144.png?12

OR 11
http://modeles.meteo...11-1-156.png?12

Or 15
http://modeles.meteo...15-1-180.png?12

Or 18
http://modeles.meteo...18-1-180.png?12

Remember the prediction ENSEMBLE MEAN to -8c for londres on the 23rd

The GFS is edging west every run!
S

Edited by Steve Murr, 16 January 2012 - 17:11 .

[Frosty039]

KTtom, on 16 January 2012 - 17:03 , said:

http://www.wetterzen...s/Rtavn1441.png The +144 chart is probably the best of a dismal set(12z GFS)! Nothing remotly wintry in that run, some innacurate posts IMO so far on this thread. Still, its only 1 run!

The Gfs 12z looks more wintry than the 00z which had the uk in 8-10c relatively mild air next sat/sun, the 12z doesn't and it looks similar but not as good as the Ukmo 12z so there are some positives, it's improving for a cold weekend.

Edited by Frosty039, 16 January 2012 - 17:15 .

[Frosty039]

Zakos, on 16 January 2012 - 17:10 , said:

Its your opinion and I respect that. I wasn't being mean (sorry if I came across that way) Exactly! This is the pattern change forecast by GP! Thats why we havent seen anything like this is the last 6 weeks. just because it hasnt happened yet doesnt mean its not going to, infact statistically its probably more likely that we do see cold I do see your point, and were not not going to know for sure for a good while yet with all this uncertainty. But you cant argue that these are the best charts this winter, and they continue to get better each run (more or less)

Yes the Gfs is still playing catch up after a poor start today, i'm happy with the gem, ecm and ukmo at the moment from a colder perspective.

Edited by Frosty039, 16 January 2012 - 17:17 .

[happy days]

Well at least there is a gentle conflict of opinion on the MO this evening but im in the 'hmmm,not sure lets wait and see variety'.Maybe its my eyes but GFS actually looks better at 144h than UKMO IMO,the trough drops a lot faster into Europe on GFS and allows some ridging west of the high across Wester Russia.
Still need to see the pattern back west 2 hundred miles if we are going to benefit IMO,Central Europe looks good for a cold blast though.

[gottolovethisweather]

chionomaniac, on 16 January 2012 - 17:00 , said:

Synoptically there is not far for the cold air mass boundaries to change for during the next few runs to leave us in the cold air.

And I think that everything will be a little further west as the negative zonal mean anomalies put a stop on the eastward flow.

Just for FUN, at T+192:

Rtavn19217.png

Reminds me of Dads Army. So close for the south.

You are such a tease Chinio.

The floodgates should certainly be opened in the not so distant future and to my mind, one question remains.

From which direction, will the Dad's Army battalions be attacking us?

At this stage, come t+120 and beyond, I would hedge my bets at say, 60% in favour of the north west, 30% in favour of the north east and only 10% likelihood a south western air mass attack.

I am most definitely looking forward to the next few runs from all the various models.

Regards

gottolovethisweather

Edited by gottolovethisweather, 16 January 2012 - 17:22 .

[weathe20]

Steve Murr, on 16 January 2012 - 17:10 , said:

Guys a will take a large slice of PTB 1 to go please-

http://modeles.meteo...-1-1-150.png?12

OR 5
http://modeles.meteo...-5-1-162.png?12

OR 7
http://modeles.meteo...-7-1-144.png?12

OR 11
http://modeles.meteo...11-1-156.png?12

Or 15
http://modeles.meteo...15-1-180.png?12

Or 18
http://modeles.meteo...18-1-180.png?12

Remember the prediction ENSEMBLE MEAN to -8c for londres on the 23rd

The GFS is edging west every run!
S

Sure is >

[danm]

GFS at 144 we are so close to a cold easterly:



...but it doesn't quite reach us. But if you compare this chart with the corresponding chart from the GFS 6z (below), we are closer to being affected by that easterly. As Nick Sussex said, the PV is more elongated, and that pesky low sitting over southern Greenland has more energy going north rather than east compared to the 6z. As a result the easterly edges a little closer, and we see more ridging of heights towards Svalbard from the Russian high. If we can see the PV back a little further west, and if the low over S. Greenland continues to see energy diverted north, rather than east (i.e become less flat) then that gives us a greater chance that the easterly will reach our shores on the GFS.

Here is the GFS 6z for the same time to compare:


Plenty of potential out to 144 on the GFS. Whether that potential will translate to an outcome remains to be seen.

Edited by danm, 16 January 2012 - 17:22 .

[RAIN RAIN RAIN]

Steve Murr, on 16 January 2012 - 17:10 , said:

Remember the prediction ENSEMBLE MEAN to -8c for londres on the 23rd

Nope.



-6 at its coldest.

[phil n.warks.]

We will have to see what the ECM shows later but to me the GFS and UKM are pretty close out to T144hrs..showing a colder NW flow but with the deeper cold just to our east.
http://www.meteociel...44-21.GIF?16-17
http://modeles.meteo...12-0-144.png?12
That Azores high is still reluctant at this stage to move far enough away to allow that trough from Scandinavia to disrupt further west which would bring the cold to us.

It`s a close thing on these runs with the Atlantic just strong enough to hold back anything from the east just now.
It`s worth watching for further vortex disruption over Greenland/Iceland -if things react as the background factors suggest.
We are looking for the jet to buckle some more as it loses energy from the weakening vortex.
As it continues to disrupt and throw more shortwaves south east there`s more opportunity for one of these to undercut the block to our north east.Something like this
http://modeles.meteo...12-5-192.png?12
That is at the end of the HR part of the run but if the GFS is shown to be over progressive then this could happen sooner.

Things are finally balanced so the slightest change in the amount of energy from upstream will have a big influence on the temperatures for our little island.

Edited by phil n.warks., 16 January 2012 - 17:38 .

[Zakos]

This animation illustrates the pattern change very well - http://policlimate.c..._mslp_natl.html

Low heights over Greenland and Arctic right now -http://policlimate.c...mslp_natl_1.png

Heights rise significantly by the end of the run despite us missing out on the cold on this run.http://policlimate.c...slp_natl_65.png

[BLAST FROM THE PAST]

shedhead, on 16 January 2012 - 16:47 , said:

Indeed HD, yet another close but no cigar run from GFS, but we've seen cold weather remain tantalising close to our E/NE on many occasions in the past - tapping into it is a different proposition altogether though. On
the plus side however it is at least likely to be in situ come this time next week, which is not something we've been able to say hitherto this Winter, so all is far from lost re Feb at this stage.

You have just completely written the rest of Jan off. The way the GFS has and is coming round and the amplification we are seeing 120 then I may suggest that not all is lost for the last 7/8 days of Jan either? UKMO could develop onto deep cold and I think Old met man mentioned earlier, the SW following just south of Greenland would IMO either quickly get absorbed SE ward into first trough or IMO just not develop into anything and just not be there as we get neartime.

BFTP

[shedhead]

BLAST FROM THE PAST, on 16 January 2012 - 17:47 , said:

You have just completely written the rest of Jan off. The way the GFS has and is coming round and the amplification we are seeing 120 then I may suggest that not all is lost for the last 7/8 days of Jan either? UKMO could develop onto deep cold and I think Old met man mentioned earlier, the SW following just south of Greenland would IMO either quickly get absorbed SE ward into first trough or IMO just not develop into anything and just not be there as we get neartime.

BFTP

I have not completely written the rest of Jan off, I'm simply suggesting Feb offers the greater potential. My earlier post talked about little change across the hi res part of the run, which ends on the 24th and still leaves a week of Jan to go.

[s4lancia]

For me a great set of 12z charts (still awaiting the start of the ECM run, hoping for a good one too).

Strange how we all see things differently though. Some people only seem to see the end results of a model run, i.e. if that run verified will it snow, how cold will it be etc etc. I see a tipping point that is very very close to being reached and when it does we will be seeing very different charts. Still expecting more amplification to be fed into the models over the next couple of days and a westward trend

[Cumulonimbus Tower]

NOGAPS is a thing of beauty (to my untrained eye) tonight (For cold fans) and if the ECM follows it to only half the degree it did this morning then they will be shouting Blizzards from the rooftops by 7 pm this evening

[Weather wizard]

ECM very similar to GFS but doesnt develop the low in the atlantic at 96h