Model Output Discussion 01/09/17

[weirpig]

some quite big differences even at 144 on the gfs 6z   heights into greenland alot more stable  also height rises the otherside of the pole  are also alot more pronounced 

Another run  different outcome   this one much more chillier feel 

Edited October 26, 2017 by weirpig

[Polar Maritime]

Yes the 6z shows much stronger ridging into the Arctic, Unable to upload chart currently but the team are looking into it. This problem only seems to be with uploading from the Netweather suite.

 

Edited October 26, 2017 by Polar Maritime

[phil nw.]

1 hour ago, Singularity said:

It is interesting how the models seem to have this recurring idea of putting one of those mid-Atlantic ridges up toward Greenland, but with seemingly no real clue when this will actually take place, assuming it even does at all. Then again, I remember far too many of these 'dangling carrot' situations in recent winters. It just seems to be how NWP modelling tends to go.

Yes the Atlantic jet still rather weak.Wave 2 action still evident in the next  week or 2 and with polar vortex formation still a way to go- we often see these ridges heading well north of 60N around this time of year.

A tricky period of modelling with the 500hPa wave lengths not clearly defined.

It still looks like a brief cooling off for us as we import air more from the north over the week end with some night frost and then next week as that Atlantic high topples over us and sinks something more changeable from the west looks likely.

 

 

[feb1991blizzard]

2 minutes ago, Polar Maritime said:

Yes the 6z shows much stronger ridging into the Arctic, Unable to upload chart currently but the team are looking into it.

 

Ive done it for you.

Edited October 26, 2017 by feb1991blizzard

[tight isobar]

'Neatly difined ridging'...via 6z..

The morphing of waa-eastern usa-greenland coming into reliable time frame.

With continue of vortex pressure punch!...

[Polar Maritime]

're chart uploading from Netweather suit'

"We're in the process of moving the attachments to a new system, I'm hoping that this'll sort itself out once that has completed in a couple of hours."

[northwestsnow]

6Z is perfect for Bonfire night weekend with a cold frosty set up under light winds i would imagine ..heres hoping.

On the flp side it looks pants thereafter with the high drifting into Europe and an angry looking Atlantic.

Edited October 26, 2017 by northwestsnow

[karlos1983]

9 minutes ago, northwestsnow said:

6Z is perfect for Bonfire night weekend with a cold frosty set up under light winds i would imagine ..heres hoping.

yes perfect, proper nice cold Bonfire night, not seen one of them for many years!! Certainly seems that way anyway. Entire UK under negative 850 temps and high pressure smack bang over us (no pun intended ) should make for very seasonal evening. 

Bloody shame it wont look like that come the 12z 

Edited October 26, 2017 by karlos1983

[MP-R]

7 minutes ago, karlos1983 said:

yes perfect, proper nice cold Bonfire night, not seen one of them for many years!! Certainly seems that way anyway. Entire UK under negative 850 temps and high pressure smack bang over us (no pun intended ) should make for very seasonal evening. 

Bloody shame it wont look like that come the 12z 

Don't forget only last year it was cold on Bonfire Night, just not from a high pressure scenario, rather northeasterly winds on the western edge of a trough. Funnily enough, before then, the last cold crisp Bonfire Night I can remember was 2006, and we all know how the rest of that November turned out...

Needless to say, encouraging signs of brighter colder weather into November, most likely from high pressure settling over either a brief or more direct northerly. Even before then, a general cool down from tomorrow over the weekend.

[karlos1983]

22 minutes ago, northwestsnow said:

6Z is perfect for Bonfire night weekend with a cold frosty set up under light winds i would imagine ..heres hoping.

On the flp side it looks pants thereafter with the high drifting into Europe and an angry looking Atlantic.

I like the last frame (because  its gonna happen right?) heights building over scandi locale, and trough disruption to our West... thing of dreams if it were December?Jan/Feb. 

[northwestsnow]

Just now, karlos1983 said:

I like the last frame (because  its gonna happen right?) heights building over scandi locale, and trough disruption to our West... thing of dreams if it were December?Jan/Feb. 

Haha yes the last frame offers interest..

Its worth noting November can deliver decent snow events for the UK though,granted its rare but 2010 i think it was provided superb snowy weather imby.

Now the clocks are going back in a few days that makes quite a difference, i really hope we dont get an Atlantic driven set up in November, although my preference is heat in summer and snow in winter there is something special about a cold foggy set up in November, esp for someone who likes walking in the pennines where i live.:)

[weirpig]

Control  similar to the OPP   also brings us into a more direct northerly flow.

[tight isobar]

Cut off point:

@138-144hrs via all operationals..

 

By the above time-frame/frames its an open book.in as far as any prominent block sets up-or indeed doesnt' and revert to mobility converts.

Or...ample block placement align's and further warmth cuts into the pole..opening' a variety of outcomes via omega block♎!/complete vortex split/an evolution of scandinavian block form setting up/or a very intresting sync' of a new found evolution.

However with the northern hemispherical state(@present)...

It is again...a very open book after mentioned time frame.

But clearing in the woods should begin to prevail next 24/48hrs cross suites!?

A real interesting start.....

No matter the eventual outcome @this early part!

♎

Edited October 26, 2017 by tight isobar

[mb018538]

15 minutes ago, northwestsnow said:

Haha yes the last frame offers interest..

Its worth noting November can deliver decent snow events for the UK though,granted its rare but 2010 i think it was provided superb snowy weather imby.

Now the clocks are going back in a few days that makes quite a difference, i really hope we dont get an Atlantic driven set up in November, although my preference is heat in summer and snow in winter there is something special about a cold foggy set up in November, esp for someone who likes walking in the pennines where i live.:)

In all fairness - the clocks going back doesn't make a jot of difference! The days are still the same length!

I always feel once Halloween is over we can properly start having a look. Much like trying to get a warm spell in late April/early May - it could happen, but it's usually just a tad early. Once November is here, we are into the right territory. Looking forward to the ups and downs as usual!

[blizzard81]

58 minutes ago, northwestsnow said:

6Z is perfect for Bonfire night weekend with a cold frosty set up under light winds i would imagine ..heres hoping.

On the flp side it looks pants thereafter with the high drifting into Europe and an angry looking Atlantic.

The Atlantic looks odds on for the second half of November unfortunately but nothing unusual about that. Let's just hope it blows itself out by early to mid December. Unlike recent winters. 

[blizzard81]

On the subject of cold crisp Bonfire nights. The vast majority I remember were very damp, muddy mildish affairs. And I was a child of the late seventies/early eighties. Infact one of the coldest Bonfire nights I remember was in the late eighties. I remember the local weatherman Bob Rust forecasting minus 3 for our area. We all know what the late eighties winters brought us. And it wasn't snow lol. 86/87 aside. 

Edited October 26, 2017 by blizzard81

[weirpig]

Grs Opp  very much an outlier past bonfire night  off course a long way out but nice to see the mean continues below the 0 isotherm   

[Snowy Hibbo]

Now I will show the forecast for some more climate drivers and sub-seasonal forecasts.

The AO is going for a positive phase in the next week. CFS then forecasts a general period of -AO (weaker jetstream, weaker vortex) over the month of November and then a general period of +AO (stronger jetstream, stronger vortex) over the month of December.

The NAO is going for a less well defined outlook, but a general -NAO phase is forecast on CFS from now until about November 24. And then a period of a somewhat +NAO forecast until the end of December, and then a few up and downs into January.

More tomorrow... much better quality post then. Thanks. 

 

[blizzard81]

1 minute ago, Snowy Hibbo said:

Now I will show the forecast for some more climate drivers and sub-seasonal forecasts.

The AO is going for a positive phase in the next week. CFS then forecasts a general period of -AO (weaker jetstream, weaker vortex) over the month of November and then a general period of +AO (stronger jetstream, stronger vortex) over the month of December.

The NAO is going for a less well defined outlook, but a general -NAO phase is forecast on CFS from now until about November 24. And then a period of a somewhat +NAO forecast until the end of December, and then a few up and downs into January.

More tomorrow... much better quality post then. Thanks. 

 

Would rather all that was the other way round. Oh well, it is the cfs so let's hope it is wrong again lol. 

[Derecho]

So a chill for eastern areas this weekend and settled for a while thereafter. What strikes me about current charts is the weak Atlantic, with lower then normal SLP around the Azores a frequent occurance in recent weeks.

Seems to be signs of more blocking to our NW later on. Also bear in mind there is strong model agreement on the first major cold air outbreak across the northern US and Canada in around 7-10 days time which could have implications, depending on where the cold air filters to. If its the SE US this could really boost blocking, if it filters out through Newfoundland and into the North Atlantic it may give it some more energy.

Worth keeping an eye on.

Edited October 26, 2017 by Quicksilver1989

[smich]

2 hours ago, tight isobar said:

'Neatly difined ridging'...via 6z..

The morphing of waa-eastern usa-greenland coming into reliable time frame.

With continue of vortex pressure punch!...

Early doors but an encouraging chart with the 2 disparate vortices over Canada and Siberia.

Are there any other forecast models that are particularly useful with regards to the PV? 

[karlos1983]

2 hours ago, blizzard81 said:

The Atlantic looks odds on for the second half of November unfortunately but nothing unusual about that. Let's just hope it blows itself out by early to mid December. Unlike recent winters. 

Interesting. Met office go for settled 2nd half of November with temps around average, possibly below average in the south.... That's quite a difference to the Atlantic driven weather you are anticipating. 

With the AO & NAO set to go positive I would agree with you.... wonder what they are seeing to go for settled conditions 

[jvenge]

10 minutes ago, karlos1983 said:

Interesting. Met office go for settled 2nd half of November with temps around average, possibly below average in the south.... That's quite a difference to the Atlantic driven weather you are anticipating. 

With the AO & NAO set to go positive I would agree with you.... wonder what they are seeing to go for settled conditions 

The thing is with Atlantic driven doesn't mean it drives storm tracks right through the UK. Looking at where the ENSO sits and the QBO, one can understand why Atlantic driven seems plausible, but if it was all such a simple calculation, we would have accurate models months out :-)

 

[karlos1983]

7 minutes ago, jvenge said:

The thing is with Atlantic driven doesn't mean it drives storm tracks right through the UK. Looking at where the ENSO sits and the QBO, one can understand why Atlantic driven seems plausible, but if it was all such a simple calculation, we would have accurate models months out :-)

 

Yes, I understand that, but it certainly doesn't mean dry settled conditions. More of "an unsettled period, interspersed with dry spells and wind from a westerly or south westerly direction". Certainly not suggesting simple calculations to predict the weather, I've been around long enough to know that's not the case. :-)

Being an island on the Door step of the Atlantic, Atlantic driven weather generally means unsettled weather, 

Edited October 26, 2017 by karlos1983

[jvenge]

Not that it means much at this range, but the GEFS mean is pointing to below average temperatures for most of Europe (including the UK) from T174 onwards. It is much more bullish on it than the 0z. 

It is actually quite rare to see the ensemble mean so pronounced at that range.