Model Output Discussions 06z 04/11/16

[Frosty.]

Plenty of polar air on the Gfs 18z with just short-lived milder interludes separating us from the next NWly cold shot, I would much rather have it this way than the mushy mild  swly zephyrs!

Edited November 12, 2016 by Frosty.

[Singularity]

The key point to understand is that this theme of a trough dropping into Europe and warm air moving north a little to the east and somewhat further to the west in association with expansive area of high pressure is a very good way to interfere with the vortex and work toward a high-latitude blocking regime. I expect that's one of the main reasons why we keep seeing these interesting longer-range signals from EC and GloSea5. The ongoing MJO (well, Convectively coupled Equatorial Kelvin Wave...) activity looks to be an important catalyst for these developments.

While we could still end up on the wrong side of a trough and/or major block in the end, we should at least get to play for the big prizes in the first half of this season

[Frosty.]

Another feature of the Gfs 18z is that we were a gnat's whisker away from full blown arctic airmass and yet we still ended up with reloads of polar maritime so on future runs we could see the arctic floodgates open wide..plenty for coldies to be encouraged about, not only later next week but through the rest of November and beyond.

[DR(S)NO]

2 minutes ago, Frosty. said:

Another feature of the Gfs 18z is that we were a gnat's whisker away from full blown arctic airmass and yet we still ended up with reloads of polar maritime so on future runs we could see the arctic floodgates open wide..plenty for coldies to be encouraged about, not only later next week but through the rest of November and beyond.

I think you're right Frosty ... It seems to me that as we move towards the latter stages of November were looking at greater chances of wintry weather ..... Before winter proper begins. 

[Mucka]

Looking through GFS nesembles it is noticeable how they tend to bring in some form of blocking from around day 10. 

In fact the Op run is probably among the least blocked runs in FI so good news there.

The issue as always is maintaining and strengthening that signal into the more reliable time-frames.

If this isn't just run to run variance and we get even a little consistency we should see some much more promising operational output tomorrow.

Certainly blocking isn't going to take hold as quickly as I thought it would in 2nd half of November but I have not given up on a cold shot proper before November is out by any means.

[feb1991blizzard]

A few more dropping now but still need to start stepping things up (or should I say down really!) and really need to see the trend setting in.

[ITSY]

Some more crazy FI Synoptics in the ensembles, although by no means an overwhelming majority just yet. As Fergie has repeatedly said, I expect the new week will determine the trend and deliver some crazy swings and even crazier Synoptics. Fun times - let's hope the possiblilities afoot deliver...

Edited November 13, 2016 by ITSY

[Daniel*]

Much talk of a front loaded winter well JMA is going for a coldie bonanza, extensive northern blocking, featuring through across the winter period (D/J/F) perhaps +ve pressure to the n/nw waning a tad in January and then reasserting in February a noteworthy winter if so. Of course no LRF models are infallible especially this model - I'm not quite sure on how JMA performs but interesting all the same. 

 

Edited November 13, 2016 by Changing Skies.

[Walsall Wood Snow]

Despite the very cold November musings back in October only been half hearted in the end, I do believe based on past experience this should have been expected and considering the time of year it is, is actually a good thing. To explain, I've noticed in the past that cold signals are often picked up prematurely by the models as well as been suggested by the background signs to occur sooner than was actually the case. For example I remember in February 2013 there was a fair bit of expectation that that month would turn out very cold, only for when the month progressed for it to be somewhat cold, but nowhere near as cold as earlier signals suggested. But because of the tendency of the long range models to bring it in earlier than what ultimately transpired there was a fair bit of toy throwing on this forum, only for March to eventually deliver in the end, which back in say January that year was little expected (and understandably so considering March is a meteorological Spring month and nothing like that March had occured for a very long time). Also lets not forget last Winter when there was much speculation of late Winter possibly delivering i.e. February, but in the end the cold came later in March (though nothing on the scale of 2013, but things were very different that year) and April even. As for now this is perhaps a good sign that though cold has been predicted this month (and it has so far occured, but nothing major as yet) due to the premature nature of long range models, this is a good sign it will ultimately occur but later than it  was initially projected , and due to the time of year, occur at a much more conducive time to when we can hopefully take much more advantage of it i.e. in December. And I'm sure most of us would prefer that anyway. As ever though we'll see.

Edited November 13, 2016 by Walsall Wood Snow

[Mucka]

GFS quite different by day 10 again this morning with a very complex and slow evolving pattern though a good one if you want blocking.

We would actually enjoy a mild spell of weather if it happened during the transition although prior to this it extends our chilly spell by putting us in a cold col.

And really that is where the action is, day 5 through day 8, as that is where the upstream issues the models are struggling so badly with will be resolved.

Meanwhile GFS continues its tortuous evolution throughout FI finally delivering in its last frames. (GFS such a tease)

I guess if it turned out that way we wouldn't mind suffering the convoluted way it got there, but of course it won't happen like that. 

 

GFS ensembles.

Looking at the staggering array of solutions at just 144 in the Atlantic sector it seems this will take a while to resolve (for GFS at least but the other models seem to be struggling just as much - conflicting background signals)

 

Edited November 13, 2016 by Mucka

[Polar Maritime]

The Net/W MR Model shows the warmer air moving away by Wednesday, Introducing a colder N/W flow for the remainder of the week with overnight frosts for some and a chance of some wintryness over high ground especially in the North.

As Mucka alludes to above^  The conflicting background signals continue throughout the Models into the start of Winter, But the theme of a blocked Atlantic still very evident this morning..

Latest Strato musings from Matt.. 

 

Edited November 13, 2016 by Polar Maritime

[Banbury]

7 hours ago, Walsall Wood Snow said:

Despite the very cold November musings back in October only been half hearted in the end, I do believe based on past experience this should have been expected and considering the time of year it is, is actually a good thing. To explain, I've noticed in the past that cold signals are often picked up prematurely by the models as well as been suggested by the background signs to occur sooner than was actually the case. For example I remember in February 2013 there was a fair bit of expectation that that month would turn out very cold, only for when the month progressed for it to be somewhat cold, but nowhere near as cold as earlier signals suggested. But because of the tendency of the long range models to bring it in earlier than what ultimately transpired there was a fair bit of toy throwing on this forum, only for March to eventually deliver in the end, which back in say January that year was little expected (and understandably so considering March is a meteorological Spring month and nothing like that March had occured for a very long time). Also lets not forget last Winter when there was much speculation of late Winter possibly delivering i.e. February, but in the end the cold came later in March (though nothing on the scale of 2013, but things were very different that year) and April even. As for now this is perhaps a good sign that though cold has been predicted this month (and it has so far occured, but nothing major as yet) due to the premature nature of long range models, this is a good sign it will ultimately occur but later than it  was initially projected , and due to the time of year, occur at a much more conducive time to when we can hopefully take much more advantage of it i.e. in December. And I'm sure most of us would prefer that anyway. As ever though we'll see.

????

I don't recall seeing anything that suggested November would be very cold

[Ravelin]

Interesting models again this morning, though this frame of the ECM was especially so. Look at the height from Russia pretty much across to Alaska. 

And you have this from the GFS at the same time. Not as spectacular, but similar. 

[IDO]

8 minutes ago, Polar Maritime said:

The Net/W MR Model shows the warmer air moving away by Wednesday, Introducing a colder N/W flow for the remainder of the week with overnight frosts for some and a chance of some wintryness over high ground especially in the North.

As Mucka alludes to above^  The conflicting background signals continue throughout the Models into the start of Winter, But the theme of a blocked Atlantic still very evident this morning..

Looking at the anomalous mean uppers and it is a minor cool spell for some, as it mostly is from that direction for many further south and east. Between -2 to -4c below average uppers for east of the M1:

The short milder spell giving +8 to +10 anomalous uppers^^^. 

A bit of consistency from the D10 ECM op, which is surprising...   

...bearing in mind the spread from D8 on the De Bilt ensembles, so as GFS op now showing various clusters after D7 as to how the battle between the three forces interact (Russia & Azores HP and the less organised vortex to our NW)? Would not like to take a guess yet, as the GEFS suggest no current trend or dominant cluster.

So next 7 days in the reliable; mild followed by cool, with the latter being dominated by the UK under a warming out trough. Although the wind's origin sourced from the NW/N, more westerly veering SW>S on the surface, so for the south feeling close to average, though going below average the further N/W you move and the Highlands bitter at times. Plenty of showers the further west you are, D4-7.

[bluearmy]

Tough to put much detail on what surface conditions are likely behind next weekend once the trough begins to fill out. 

the trends remain the same

euro upper trough becoming established though not a deep feature on the means (that could change I guess, though not sure where 're enforcements'  would come from seeing as the Atlantic ridge seems quite strong )

russian ridge stays in situ though perhaps slowly giving ground as time ticks on towards the back end of the month. 

no stong vortex

this chart should tell you plenty about what to expect for the next fortnight once we see this weeks nw flow abate.

its late November!  (Reminds me of my seventies childhood - bring on the fog! )

[Frosty.]

The Ecm 00z ens mean shows a mild spell early in the week with a mid atlantic airmass but by midweek its changing as lowering heights swing down from the NW with associated progressively cooler / colder polar air and its an unsettled trough dominated outlook with temps generally below average and rather cold at times, especially in the north. We will all see showers and longer spells of rain, it will be windy at times and over northern hills, expect snow at times, perhaps occasionally to lower levels in the far north and modest hills of the south could have a wintry mix. Nights look chilly with occasional frosts and some sharp frosts over highland snow fields. 

Edited November 13, 2016 by Frosty.

[legritter]

Morning all ,Very interesting looking at current charts ,we can fathom out the generall weather up untill next weekend but looking on ECM its what happens to the next low at days 7/8 will it move S east or sit across us ,or even come in further north ,all of course throwing up interesting possibilities and different weather for the UK .

Perhaps current GFS run can throw some light on this , well lets see where we are in tonights runs , interesting and challenging times for us weather fanatics ,cheers 

[bluearmy]

2 minutes ago, legritter said:

 

Perhaps current GFS run can throw some light on this , 

that's the easiest question ever placed on this forum! 

[northwestsnow]

Still on course for the block to the east to become more influencial longer term IMO-

Pattern looks generally stable, mild few days coming up, gradually cooler as we move through next week, short spell of Atlantic then the block takes over.

Sounds simple, obviously it isn't, but iv'e not seen anything on the 00z runs to alter the above.

And Blue mentioned, FOG on the agenda for later Nov as we pick up a continental feed - i think its at this point we really dont know what will happen, the hope for coldies is the block retrogresses, i still think it looks good for a seasonal/cold end to November :).

EDIT: 6z a couple of degrees colder by the end of the week - might be the odd suprise with a cheshire gap streamer on fri night

Edited November 13, 2016 by northwestsnow

[ITSY]

As if this needed stressing, but look at some of the options in FI - the models are clearly toying around with something! 

 

 

[cheshire snow]

17 hours ago, northwestsnow said:

Still on course for the block to the east to become more influencial longer term IMO-

Pattern looks generally stable, mild few days coming up, gradually cooler as we move through next week, short spell of Atlantic then the block takes over.

Sounds simple, obviously it isn't, but iv'e not seen anything on the 00z runs to alter the above.

And Blue mentioned, FOG on the agenda for later Nov as we pick up a continental feed - i think its at this point we really dont know what will happen, the hope for coldies is the block retrogresses, i still think it looks good for a seasonal/cold end to November :).

EDIT: 6z a couple of degrees colder by the end of the week - might be the odd suprise with a cheshire gap streamer on fri night

Cheshire Gap streamer you are such a tease NWS

C.S

[Ravelin]

13 minutes ago, ITSY said:

As if this needed stressing, but look at some of the options in FI - the models are clearly toying around with something! 

I'm not sure the 6Z has clarified exactly what though. The GFS clearly thinks that after next weekend there will be a cut off low of some description to our West. How that then develops, well I'm not sure we'll have any clearer an idea on that for another day or two. 

As by example, the t240 charts for the 6z and the 0z...

  

Edited November 13, 2016 by Ravelin

[MR EXTREMES]

well the gfs in its later runs would go on to show easterly flow!

low dropping down south/southeast across the uk into germany then u see heights rising  slightly north of iceland.

 to our east and scani height rising and retrogressing north and northwest certainly a link up possible.

all the time we have block to our east north east and west northwest we had lower heights to our south which is good step in the right direction.

after the second low pressure shown in this chart moves through thats when the coldies doors will open.

although possibly a slow evolution into a cold set up.

the other alternative is low gets stuck to our west.

but if it drops south southeast like the the first low then could get flow from north northeast then east like 09/10

 

Edited November 13, 2016 by MR EXTREMES

[Captain Shortwave]

      

Looking into the rest of November, it certainly seems like we will see a trough over the UK which looks likely to sharpen and weaken as time progresses as the pattern becomes more amplified and slow moving. I can certainly buy the idea of some sort of high developing across the UK as the month ends as the Atlantic and Russian ridges bridge a cut off low to our south, unsettled for a time before becoming more showery and then eventually drier with frost and fog perhaps. An interesting set up as we might be seeing a holding pattern develop, very similar to some of the classic winters where we see a more blocked but not necessarily cold pattern set up before the arctic floodgates fully open a week or two further down the line.

The GFS 06z looks pretty good in that regard

      

Once the high gets into that position, we can see the high drift north/north east to develop a cold continental flow or indeed retrograde towards Iceland/Greenland for a more northerly blast. The Arctic profile looks very pliant in that regard so a lot of options on the table for the end of the month, not a lot of them look mobile.

[bobbydog]

More FI shenanigans from the GFS-

00z

06z

I suppose we can't call two runs a trend.

But hey, trending on the GFS-#Blocking....