Model Output Discussions 06z 04/11/16

[Frosty.]

The Gfs 6z shows Scandinavia having a very cold outbreak while we are sat under high pressure before the southwesterly zephyrs kick in through low res..potential..sigh! 

Edited November 27, 2016 by Frosty.

[snowflakey]

13 minutes ago, Steve Murr said:

The GFS mean at 120 keeps the atlantic low as one entity with minimal trough disruption ( as per Euros ) 

Until till it resolves this & moves the energy into x2 split areas - one further SE & the other further NW it will continue to create a positive tiltes low at 168 & flatten the block

The second it gets decent seperation the energy will go under...

energy in the jet seems to be split with the lions share going under

 

[SMU]

Its more the actual trough disruption of the low itself

look at UKMO 120 at the same time...

[feb1991blizzard]

Notice the at the end of the 0z eps, there is a small cluster that has the daytime max's for London only just above freezing, the fact that there is one run really frigid (the only way these temps would occur for London would be usually be potent Easterly), I wonder if the cluster are straight after a successful undercut and the others will really start to drop on future runs, the GEFS and GFS while look fraught with danger of subsequent  rampant PV over GL, they are showing a split (backed up by strat) that if any Easterly did ensue, uppers on a par with 91 or 87 could occur - maximum risk for maximum reward, It always seems to me that the really brutal Easterlies have the frigid air coming round the back of the developing scandi high via a thin wedge of vertical advection as opposed to one toppling from Greenland.

Edited November 27, 2016 by feb1991blizzard

[nick sussex]

I'd happily take the ECM at day 10 if offered that. Its not just about strong blocking so those heights to the north would be fine especially as the PV looks like splitting with one lob heading west and the other se.

Unfortunately its at day 10. The GFS however is very determined to pile all the energy ne and this is a bias with it hence its XXX rated lower FI output.

These set ups are hard to forecast because trough disruption is poorly handled by the models who don't particularly like this juggling act between energy going ne and se, as long as you maintain some more positive heights near Iceland and southern Greenland then I'd be wary of outputs that steam roll the energy all ne like the GFS.

 

[knocker]

Lovely Jubbly

[Frosty.]

10 minutes ago, nick sussex said:

The GFS however is very determined to pile all the energy ne and this is a bias with it hence its XXX rated lower FI output.

 

 

Indeed Nick, the Gfs 6z shows a very mild southwesterly airflow for the first full week of December, charts remind me of last December. so, there is more potential for it to become very mild than cold, the serious cold is further NE / E and even that gets bulldozed out of the way in low res as all the mild mid atlantic energy spills over the top of the Azores high..sounds familiar with a UK winter about to start doesn't it!

Edited November 27, 2016 by Frosty.

[Methuselah]

Well, another day, and another plethora of runs have been perused (not counting occasional dips into the 'desperation models') and still we don't know what's going to happen? It seems that the good, old UK weather remains determined to make mugs out of humans and machines alike?

[SMU]

This run from 06z NAVGEM is exactly where the forecast should be today--- this should be the super ensemble run-

http://www.meteociel.fr/modeles/navgeme_cartes.php?ech=6&code=0&mode=0&carte=0&archive=0

[nick sussex]

4 minutes ago, Frosty. said:

Indeed Nick, the Gfs 6z shows a very mild southwesterly airflow for the first full week of December, charts remind me of last December. so, there is more potential for it to become very mild than cold, the serious cold is further NE / E and even that gets bulldozed out of the way in low res as all the mild mid atlantic energy spills over the top of the Azores high..sounds familiar with a UK winter about to start doesn't it!

I wouldn't trust the GFS with this pattern. If the ECM bails out then fair enough we'll accept our fate however we've been here before with the GFS and its obsession with blasting the energy ne.

[feb1991blizzard]

Just now, KasimWeatherQuarnford said:

How long does it take to fully role out? Thank you..

Its already fully out, it goes only to 144

[Captain Shortwave]

7 minutes ago, Frosty. said:

Indeed Nick, the Gfs 6z shows a very mild southwesterly airflow for the first full week of December, charts remind me of last December. so, there is more potential for it to become very mild than cold, the serious cold is further NE / E and even that gets bulldozed out of the way in low res as all the mild mid atlantic energy spills over the top of the Azores high..sounds familiar with a UK winter about to start doesn't it!

Luckily the GFS hasn't exactly covered itself in glory in the past couple of weeks. I think this sums it up;

Dude where's my Greenland high? 

I am not convinced of a return to much milder conditions as of yet, especially with the models still not uncertain on the split flow at the end of the coming week.

[Frosty.]

14 minutes ago, nick sussex said:

I wouldn't trust the GFS with this pattern. If the ECM bails out then fair enough we'll accept our fate however we've been here before with the GFS and its obsession with blasting the energy ne.

The thing is Nick, there have been other runs and other models showing a very mild swly eventually developing through early december with the jet sw / ne. I want proper cold like most on here but the potential has downgraded, it's not what most want to read but I think IDO summed things up earlier..it all has a familiar ring to it with potential turning to mush.

Edited November 27, 2016 by Frosty.

[gottolovethisweather]

20 minutes ago, knocker said:

Lovely Jubbly

 

Yep, in April, beautiful. 

[nick sussex]

In the past two weeks we've had the following from the GFS.

As CS just mentioned the phantom Greenland high, and the northerly that it hung to grimly for days whilst the other outputs didn't want to know about.

And so on current form its not upto much. And in the current set up its even more likely to lose the plot so for that reason alone I'd be very dubious about it.

My advice stick to the Euros the ECM and UKMO with this set up, if they go pearshaped then at that point we can say game over otherwise I'd keep an open mind about things.

 

Edited November 27, 2016 by nick sussex

[IDO]

3 minutes ago, nick sussex said:

I wouldn't trust the GFS with this pattern. If the ECM bails out then fair enough we'll accept our fate however we've been here before with the GFS and its obsession with blasting the energy ne.

Yet trusting D10 ECM charts will lead you to the poor house and the ECM mean is a close match to the GEFS: 

1 minute ago, Captain Shortwave said:

Luckily the GFS hasn't exactly covered itself in glory in the past couple of weeks. I think this sums it up;

Dude where's my Greenland high? 

I am not convinced of a return to much milder conditions as of yet, especially with the models still not uncertain on the split flow at the end of the coming week.

ECM mean for London indicating an uptick in temps, not the other way round: 

Those ECM D10 charts need to be treated with a pot of salt, remember yesterday's 0z: 

ECM's propensity for charts that never verify at that range is unsurpassed, so yes be wary of GFS and its Atlantic, but just as cautious to ECM at that range?

[feb1991blizzard]

1 minute ago, IDO said:

Yet trusting D10 ECM charts will lead you to the poor house and the ECM mean is a close match to the GEFS: 

ECM mean for London indicating an uptick in temps, not the other way round: 

Those ECM D10 charts need to be treated with a pot of salt, remember yesterday's 0z: 

ECM's propensity for charts that never verify at that range is unsurpassed, so yes be wary of GFS and its Atlantic, but just as cautious to ECM at that range?

Really?  eps Mean Max temps are showing only 5c for a massive conurbation affected by urban heat effect (using the latest run), uptick after 240 but then a marked drop right at the end of the run.

[Frosty.]

1 minute ago, feb1991blizzard said:

Really?  eps Mean Max temps are showing only 5c for a massive conurbation affected by urban heat effect (using the latest run), uptick after 240 but then a marked drop right at the end of the run.

A marked drop in cloud cuckoo land

[nick sussex]

IDO the means are irrelevant when dealing with trough disruption because if the operationals can barely handle that then the lower resolution ensembles will be even worse.

That's why we often see easterlies first picked up by the operationals and the ensembles much slower to react. I'm not saying its going to get much colder but simply that we should keep an open mind because I'm not convinced that all the energy is going to pile over the top.

[IDO]

2 minutes ago, feb1991blizzard said:

Really?  eps Mean Max temps are showing only 5c for a massive conurbation affected by urban heat effect (using the latest run), uptick after 240 but then a marked drop right at the end of the run.

The mean high on the 5th is 5c and the mean high on the 12th is 7.5c, where is the dramatic drop?

[The PIT]

IDO good points there. However you should always take T240 with a pinch of salt. Even more so when models are swapping and changing a lot much earlier in run as well.  The trend seems to be towards are more active Atlantic which isn't hard and a drift away from the colder pattern we've been used too.

[gottolovethisweather]

27 minutes ago, Ed Stone said:

Well, another day, and another plethora of runs have been perused (not counting occasional dips into the 'desperation models') and still we don't know what's going to happen? It seems that the good, old UK weather remains determined to make mugs out of humans and machines alike?

 

 

 

 

We do Pete before t+12,800 minutes have elapsed, it's fresh and crisp mornings on occasion for most, bright gin skies sometimes and some cloudier ones at other times.  Temperatures will barely breach double-digits by day, and there will be little if any rain. I best go, as the first chart showing the inevitable breakdown has less than 12,798 minutes now to come to fruition. Timescales guys, have faith in the here and now and come D8 maybe then we can start believing in some of the various outcomes chucked up these computer generated pieces of guesswork. 

Edited November 27, 2016 by gottolovethisweather

[Methuselah]

1 minute ago, nick sussex said:

IDO the means are irrelevant when dealing with trough disruption because if the operationals can barely handle that then the lower resolution ensembles will be even worse.

That's why we often see easterlies first picked up by the operationals and the ensembles much slower to react. I'm not saying its going to get much colder but simply that we should keep an open mind because I'm not convinced that all the energy is going to pile over the top.

Can see where you're coming from, Nick...But, what about all those easterlies the never happen? Don't we 'often see those first', too?

[feb1991blizzard]

1 minute ago, IDO said:

The mean high on the 5th is 5c and the mean high on the 12th is 7.5c, where is the dramatic drop?

I did say after D 10 a mean uptick but look at the split!!,   I am far more worried about seeing signs much deeper into FI myself as I also see this near term cold as unlikely, however, you cannot use the 0z (latest graph) to disprove the d10 operational chart..

[Banbury]

Poorish update from the Met would suggest Atlantic driven weather in the short to mid term ...............the wait for something wintry goes on. It will be interesting to see which model jumps ship first