Model Discussion Thread - 15th Jan

[Andy_]

I quite like the GFS 12Z, moving again towards the ECM and gives us a nice setup as we head into the new month. Potential being the key phrase here...

I also like how far south its beginning to model the Low Pressure systems on this inter pattern zonal period.

[snowlover2009]

GFS from this

http://modeles.meteo...12-5-150.png?12

to THIS

http://modeles.meteo...12-5-126.png?12

in 24 hours.....

S

It is amazing to see such difference in a matter of hours at a close range. Just shows it is early day. As ever, gfs slowly moving towards the euros and the 12z FI builds the proper brutal cold by the end of January. Very interesting, times I reckon for the last week of the month and most certainly February.

[bluearmy]

Sylvain - make the 12z ecm look like dec 2010 !!

Seriosuly, plenty more twists and turns to come and my eyes are drawn to the second shortwave dropping in. How small can we make the warm sector ?

[snowlover2009]

UKMO very interesting at 144 hours, looks like the pattern, that we saw at the end of January 1986!

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

http://www.wetterzentrale.de/pics/archive/ra/1986/Rrea00119860128.gif

This chart is from the 18th January 1986,

http://www.wetterzentrale.de/pics/archive/ra/1986/Rrea00119860118.gif

looking at he current models at this time frame, I personally believe we are in a better situation, so the hints we keep getting for the rest of the month into February might not be far off the mark. if, in 1986, they could get that chart and 2 weeks later, one of the coldest February's on record, then we surely have a good chance. The pattern of the winter, is awfully similar to that winter.

[nick sussex]

Optimism returns to the thread!

Some really interesting solutions on offer this evening from the models although the GFS continues to drag its heels, but given that it was wrong within 96hrs then hardly a model to read too much into at the moment.

In terms of the UKMO and whether it will topple the ridge into Europe, this is unlikely as the blocking to the east is stopping that trough over Europe so the highs got nowhere to go.

The models by and large follow the ECM ensemble mean of recent days with troughing locked in over Europe.

I think the next uncertainty is going to be where that low pressure goes near Iceland, if the block to the east extends further west this will be forced to head s/se in towards the UK.

What happens after that way too far out to call.

[snowlover2009]

http://modeles.meteo...nh-0-144.png?12

UPDATED GEM

& the NOGAPS

At 168

http://modeles.meteo...0-168.png?15-17

After near identical looking like the UKMO at 144-

http://modeles.meteo...0-144.png?15-17

SYLVIAN FIX THE NOGAPS NH LINK!!!!!

S

Wow, some big changes at a closer range! Definitely things picking up for the coldies. I have a feeling gfs 18z will fall in line or some of the ensembles will start to dig back below -10 again. All the euros have been in a great agreement, all eyes on the ecm.

[Cheese Rice]

I'm hopeful we will some sort of change on the GFS output, it seems to be stuck on a broken record with negligible difference between each output all the way up to T192.

Looking at the 6z T850 ensembles for Oslo

12Z ensembles

There is a clear divergence between the operational and the rest of the suite, this was prevalent yesterday too

Yesterdays 18z ensembles

We have only got two options.

1.) Low pressure fails to reach Oslo and we see a North West/South East Trajectory of the lows, cold air stays over our North East with high pressure centered over Northern Europe but not over Oslo.

2.) The Operational is correct and the rest of the ensembles fall in line.

You can't really have a midway point either, the high acts as a block or it transfers further east at the force of the lows.

Following on from my earlier post the 12Z is making good progress towards the first option. The high to over N.Europe/Russia is much more prevalent and most importantly further east.

What is shown right at the end of FI is a perfectly plausible evolution from the pattern we are in, you can cut everything out after T192 as I just don't see a high pushing north then building over Norway. If anything I would expect the block to our east to push further west causing a more NW/SW trajectory of the lows allowing heights to build.

.

It all really depends on the strength of the PV/hgh, any high would have to be 1035mb plus to have any chance of stopping the full force of the PV.

Edited January 15, 2012 by Cheese Rice

[snowlover2009]

& it keeps coming-

CONTROL at 150

http://modeles.meteo...-0-1-150.png?12

Mean at 144-

http://modeles.meteo...21-1-138.png?12

Some awsome ensembles

I will take number 3 7 or 13

S

Thanks Mate- Loving the NH plots on Meteociel at the mo-

Nogaps NH chart

http://modeles.meteo...0-180.png?15-17

Steve

Sorry for all the posts. I feel the significant point we need to watch, is that high pressure pushing up to Greenland, illustrated by the control run. This could be the most crucial part.

[kold weather]

Some better runs but they are still far from steller runs. We have a brief toppler northerly flow with just a few hints of maybe a short-fire NE airflow as the LP sinks away. The BIG problem is that PV placement though, its still way too close to Greenland and if you look at the UKMO for example, there is a weak shortwave working NE up the Azores High western flank at 144hrs, I've never seen that happen with a PV nearby and seen anty good results come from it. We'd probably get another quick NW/N shot before the pattern flattens right out on the 12z UKMO.

At least we are getting agreement on a brief toppler type set-up now though.

Control run would be a decent solution if we want to keep things below average.

[TEITS]

Blimey im on and off this fence like a yoyo.

Much better runs and finally the GFS has woken up and realised it was wrong. Im also posting the NOGAPS at +180 because its a scenario I suggested yesterday that could well occur.

This morning I said there was a divergence of 9C between the ensembles but this has now changed with a solid clustering around -5C.

http://cdn.nwstatic.co.uk/ensimages/ens.20120115/12/t850Cambridgeshire.png

[JP1972]

Blimey im on and off this fence like a yoyo.

Much better runs and finally the GFS has woken up and realised it was wrong. Im also posting the NOGAPS at +180 because its a scenario I suggested yesterday that could well occur.

http://modeles.meteo...0-180.png?15-17

This morning I said there was a divergence of 9C between the ensembles but this has now changed with a solid clustering around -5C.

http://cdn.nwstatic....bridgeshire.png

Hi TEITS.

For the benefit of newbie's like myself, can you tell me what the attachements mean in terms of weather please?

Thanks.

[TEITS]

Hi TEITS.

For the benefit of newbie's like myself, can you tell me what the attachements mean in terms of weather please?

Thanks.

The first chart is from the NOGAPS model. This shows that beyond the cold N,ly flow at +144 we see another low pressure system sinking SE with high pressure building to our N. This is an excellent chart with regards to prolonging the cold spell although the NOGAPS isn't the most reliable.

The 2nd chart is the ensembles for Cambs. Basically the ensembles are mainly used to check the reliablity of a model run and to take into account the chaos theory. The 12Z ensembles now show much better agreement of a cold plunge at +144.

Sorry my post is brief but im following the ECM.

[dixonoid]

Hi TEITS.

For the benefit of newbie's like myself, can you tell me what the attachements mean in terms of weather please?

Thanks.

Well the Nogaps has good blocking over greenland, and would mean cold weather, maybe prolonged, and the GFS 12z ensembles are showing a cold snap from friday 20th until about the 23rd! And because the ensembles are clusttered together, the potential is greater as there is good agreement from the control and all the perturbations, during this period.

[Matty M]

12z ECM looks well dodgy at T96hrs

as in it looks a total mess with the plot of the low around Iceland and isobars around Greenland.

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2012011512/ECH1-120.GIF?15-0

This is going to be interesting the jet is way back over the western part of the atlantic!

S

[danm]

Interesting ECM at 120:

Trough is digging south through Scandi, Azores high a bit further west and ridging further north compared to the 0z. More chance of heights building between the UK and Greenland. Let's see where this goes...

[Cloud 10]

Interesting GEM at 120hrs,looks similar to what the ecm was churning out a few days ago with

more chance of north-easterly.

[Matty M]

Almost Steve, scrap the pesky shortwave crossing southern Greenland at T120 and we could have a wee shot

[danm]

Definite upgrade on the 12z out to 144 compared to the 0z. Tantalisingly close to an easterly at 144:

Much more amplified compared to the 0z with the azores high backing west, much less flat.

[The PIT]

Amazingly good agreement between GFS and ECM from T96 to T144 suggesting FI moving out a bit from T96. I wonder how far this lovin stretches. Ah until T168 when the divergence starts.

Edited January 15, 2012 by The PIT

[Stuie]

Seeing as the focus is around the 20th there is some decent amounts of precipitation about.

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=120&mode=2

[SMU]

come to papa ECm is SLOW SLOW SLOW on the hangback & VERY tilted on that jet sreak south with some residual energy NE-

http://www.meteociel.fr/modeles/ecmwf/runs/2012011512/ECH1-144.GIF?15-0

S

[TEITS]

Amazingly good agreement between GFS and ECM from T96 to T144 suggesting FI moving out a bit from T96. I wonder how far this lovin stretches.

Now we're starting to see agreement of a cold NW/N/NE,ly the next saga begins with what happens after +144. The 12Z ECM +144 is very interesting and differs some what from the UKMO/GFS.

LOL have to laugh at following the models.

Edited January 15, 2012 by THE EYE IN THE SKY

[danm]

ECM t168 - YES PLEASE!

Shows a chilling NE'erly, with cold 850's dragged west across the UK.

Edited January 15, 2012 by danm

[Matty M]

You gotta laugh sometimes