Model Output Discussion 18th Nov.2013-12z onwards.

[festivalking]

Lol I think between your obsession with "short waves" , Steve's obsession with the gfs failings , frosty's obsession with extreme weather charts , and 700 other peoples (including me) obsession with snow we have the ingredients to be so much more than weather enthusiasts on a weather forum !!! Of course I'm a super hero by night . . . Not sure about anybody else though?!!!!

 

I'm actually surprised you don't get counsellors advertising on this site they would make a killing from all the GFS / ECM induced traumas

[gottolovethisweather]

Remember when we have high pressure in situ at this time of year the 850hpa temps become much less active when trying to determine temperature forecasts.

Inversions/surface cold can often mitigate the 850hpa modelling and thus what may appear to be a less cold airmass or even milder airmass may appear less so at the surface. We do live at the surface and not 1500ft in the sky remember!

That's not necessarily specific to any forecast modelling tonight, just a general observation!

 

Well said AWD. Yes, whether the weather effecting us at the surface is cloudy or foggy will also determine one's impression of whether it feels raw or pleasantly mild "for the time of year", should the sun come out. Winter is nearly here so I'm happy to put up with some inaction as it should allow land surface insolation (I think that's the term) to take place.  Should the ground get covered in a layer of snow beforehand needs to also be considered as we move forward, however unlikely that might seem at this stage.

Edited November 19, 2013 by gottolovethisweather

[NorthernRab]

Probably still cool at first but gradually becoming less cold all will depend on the wind direction as well temperatures for tonight's ECM will be available around 8pm so we'll get a better idea then

 

Have to say I entirely disagree - with high pressure this late in November much of the country would really struggle temperature wise, especially parts of the north and Scotland where ice days would be a possibility under freezing fog. 

[Severe Siberian icy blast]

I'm actually surprised you don't get counsellors advertising on this site they would make a killing from all the GFS / ECM induced traumas

Haha that is so true , if only they knew they had a ready made business waiting for them on hear 4/5 months of the year , and if they find themselves running low on clients they can just recommend some of their original victims come back on hear and give things another "chance" !!

[Severe Siberian icy blast]

Tendency of relative AAM has increased dramatically now I am no expert when itcomes to GWO and GLAAM but I would not be surprised to see a big switch in themodel output over the next couple of days.

Can you post the links by any chance ?Interesting what you say there , the models are so fickle at the minute

[Frosty.]

Tonight's Ecm 12z is rather cold & anticyclonic once the current unsettled spell fizzles out just before the weekend, high pressure then building in strongly and killing off any remaining showers lingering in the east on friday, a fine settled weekend and next week stays settled and chilly with low level cold air trapped within the anticyclone, no fronts or warm sectors to displace the cold air, it's a stagnant and chilly pattern with widespread frosts and fog becoming the major hazard, some of it freezing fog which may prove reluctant to clear and could hang around all day and then thicken up again during each evening..so in some respects it's wintry. By T+240 there are signs of cracks appearing in the settled spell and it's neither settled or unsettled but it's not indicating a full on breakdown, in fact it could be the reboot period of anticyclonic dominance building in from the azores. The Ecm now looks substantially inferior to it's op runs in recent days..even this morning was a downgrade and this run has taken it further..no freeze from the northeast then, another ecm flop.

Edited November 19, 2013 by Frosty.

[East_England_Stormchaser91]

Have to say I entirely disagree - with high pressure this late in November much of the country would really struggle temperature wise, especially parts of the north and Scotland where ice days would be a possibility under freezing fog. 

Yep, it certainly will not warm up under that high. Very thick fog lasting all day in most places with temps not above 2c probably. At least it will feel very tranquil and peaceful as is mostly the case when it is foggy.

[Captain Shortwave]

Lol I think between your obsession with "short waves" , Steve's obsession with the gfs failings , frosty's obsession with extreme weather charts , and 700 other peoples (including me) obsession with snow we have the ingredients to be so much more than weather enthusiasts on a weather forum !!! Of course I'm a super hero by night . . . Not sure about anybody else though?!!!!

Rest assured I am not Captain America's brother who works at the NOAA 

Ah yes the models. Well UKMO is game over straight off and the ECM/GFS whilst taking energy south east seem to show a sledgehammer going straight through Greenland. I guess whilst being sceptical of an oncoming cold spell, I guess I should allow another 24 hours to see if the models can pull this from the fire. 

The strat forecasts at least look positive though, given the favoured positioning of the lobes then I guess we will be continuing to look for the easterly (I believe).

[ICETAB]

Tendency of relative AAM has increased dramatically now I am no expert when it

comes to GWO and GLAAM but I would not be surprised to see a big switch in the

model output over the next couple of days.

When did it happen, today?

[Frosty.]

Tonight's GEM 12z looks rock solid anticyclonic @ T+240 hours, no sign of any breakdown there, the cold blast further east but closer than the ecm shows. There is a slightly wobbly period early next week as the high loses a bit of ground allowing unsettled and windy weather to brush around the top of the high across northern britain but it soon become emphatically anticyclonic beyond that point.

[Cloud 10]

Can you post the links by any chance ?

Interesting what you say there , the models are so fickle at the minute

 

 

Here is the chart and link.

 

 

ESRL : PSD : PSD Map Room: Monitoring of Global Atmospheric Angular Momentum (AAM) Budget

 

 

 

Over to GP. 

[Frosty.]

JMA 12z shows an Easterly next week across the south..doesn't look very potent though.

[radiohead]

JMA 12z shows an Easterly next week across the south..doesn't look very potent though.

I'd take that over most of the other output tonight, there's tangible potential there! Ian F often says the JMA is respected by the Met Office.

[Frosty.]

Tonight's Ecm 12z ensemble mean is very anticyclonic, even by day 10 it's still holding it's ground across much of the uk but signs that the atlantic is cranking up as we enter December, especially for the northwestern corner of the uk as the fine spell crumbles with windier and more unsettled weather returning, the high will probably sink away southeast early next month.

[bluearmy]

I'd take that over most of the other output tonight, there's tangible potential there! Ian F often says the JMA is respected by the Met Office.

Respected but not favoured ahead of the euro models.

[Frosty.]

I'd take that over most of the other output tonight, there's tangible potential there! Ian F often says the JMA is respected by the Met Office.

True although it looks like a cloudy drizzly easterly with temps at 6's and 7's celsius maxima.

[Snowmadsam]

I'm not that bothered about getting snow at the moment there's far more exciting things happening (Dr. Who, Christmas, new year etc.). Yes the models look bad from a cold POV (point of view), but then again do we really want a snowfest now? With the ground so warm? I don't thats for sure.

 

Lets all take a chill pill (see I can be down with da beatzzz innit lol!) and relax. I know its so irriatating but we will get there. Slowly.

 

Lets see what happens overnight and into the morning

[Catacol]

Here is the chart and link.

 

gltend.sig.90day.gif

 

ESRL : PSD : PSD Map Room: Monitoring of Global Atmospheric Angular Momentum (AAM) Budget

 

 

 

Over to GP. 

 

Angular Momentum does my head in... but I know GP talked of it all the time and I found this image he posted last season to help us dullards work out what it might mean.

 

 

 

 

 

 

 

 

 

 

Now the problem I have is that the graphs currently suggest Angular Momentum is pretty average... but the TENDENCY of Angular Momentum has spiked almost off the scale. This is the Calculated Tendency today:

 

 

So - what does this mean? Well currently the GWO plot (GP used to say use this and not MJO...) is suggesting a move away from blocking and more towards a mobile pattern. Phase 5 - 8 is best for blocking; phase 1 - 4 not so good. You can see from this forecast GEFS chart that we move through 5 - 8 over the next week but then drop down towards phase 2

 

 

So basically it doesnt look to me as though a spike in tendency is much to write home about in terms of looking for cold weather - but I would love someone here to be able to post something about the difference between tendency and the standard Angular Momentum plots.

Edited November 19, 2013 by Catacol_Highlander

[radiohead]

True although it looks like a cloudy drizzly easterly with temps at 6's and 7's celsius maxima.

 

Yeah the easterly itself wouldn't be too exciting, but I like how vertical the ridge is, its position out west. You could imagine a low sinking southeast cutting that off into an Iceland high...

 

[Frosty.]

Well the models are now firming up on a rather chilly and benign anticyclonic spell which could prove very reluctant to budge, especially further southeast, I think the far northwest of the uk will become unsettled again next week and relatively milder with strong winds but most of the uk looks like becoming dry with widespread frosts and fog, some of it the freezing variety, a really stagnant pattern but then signs of atlantic lows breaking through early next month, at least across the north & west of the uk. Was hoping steve might tell us everything is still looking good but with england losing to germany, pete and tong spring to mind.

Edited November 19, 2013 by Frosty.

[Bradowl]

I'm not that bothered about getting snow at the moment there's far more exciting things happening (Dr. Who, Christmas, new year etc.). Yes the models look bad from a cold POV (point of view), but then again do we really want a snowfest now? With the ground so warm? I don't thats for sure.

 

Lets all take a chill pill (see I can be down with da beatzzz innit lol!) and relax. I know its so irriatating but we will get there. Slowly.

 

Lets see what happens overnight and into the morning

 

The added bonus is if this HP stays over us for next fortnight then large parts of Europe should see a massive drop in temperature which could benefit us next month.

[Grimsby Snow Lover]

The added bonus is if this HP stays over us for next fortnight then large parts of Europe should see a massive drop in temperature which could benefit us next month.

Couldn't agree more Bradowl. I love the cold and snow etc, but its the 19th of November not the 19th Dec/Jan! November/early December 2010 was very special and something unlikely to be repeated just yet. I live in hope though.

[bluearmy]

Can we have the old ecm ens back please ?

On a more serious note, despite our side of the NH flattening out, the aleutian ridge re appears convincingly by day 10 and the siberian part of the vortex looks stronger.

The extended dutch ens keep approx half the members with a continental feed.

Edited November 19, 2013 by bluearmy

[Purga]

Brian Gaze going for a gradual warm up as we head into December.

 

although a split ENS the majority are heading mild

 

Will 18z be another downgrade??

[NorthernRab]

Brian Gaze going for a gradual warm up as we head into December.

 

 

I didn't know Brian had become a computerised meteorology model! How terrifying.