Model Output Discussion - early October

[Mike Poole]

Well as the short term forecast from the models takes us out of the seemingly endless wet weather that has afflicted most areas for some time (for a while anyway) a look at possibilities in the slightly longer term.  

First though, a breakthrough in space weather!  As of today 74% of days this year had no sunspots.  Which beats the last solar minimum (2008 had 73%), see:

SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids

SPACEWEATHER.COM

Why is this relevant, some may ask? Well this lack of solar activity seems to correlate to a more meridional (wiggly) jet stream, promoting blocking, either in areas favourable to UK cold or not.  I'm not sure how this stacks  up against other things also affecting our weather as we approach winter, e.g. Strat, SSTs, QBO and the rest of it, but around the last solar minimum we had some significant cold spells in winter (before my days commenting on here though!).

So worth a look at the situation as a more amplified jet stream takes hold, here T144 for GFS, ECM and GEM:

And the jet stream plots for GFS and GEM:

My main interest here, is should a block get established, how will it evolve, it should be really interesting to watch the interplay between an amplified tropospheric pattern such as this vis a vis a strengthening stratospheric vortex above, GFS forecast strengthens zonal winds in the strat significantly over same period:

Particularly, I'm interested in what the models are showing when we get to what is T144 now, i.e. towards the end of next week.  Late Autumn into early Winter looks really interesting to me this year, I'm less interested I guess at the moment in the charts showing immediate cool weather, than I am in those that show interest in the medium term, we will see...

 

 

Edited October 18, 2019 by Mike Poole

[SMU]

I know its the day 10 ECM but what a superb blocking chart that is for November-

Good night PV

[Frosty.]

Do not adjust your sets, this is an Ecm 12z indian summer!

[LRD]

7 hours ago, Met4Cast said:

Certainly some strange outputs appearing in the extended at the moment. Last nights EC weekly keeps positive height anomalies broadly to the north of the UK through much of November

It'll be interesting to see how any downwelling from the strat during early November impacts this forecast, could potentially be some interest during November.

That's an anomaly chart though, isn't it? So that would suggest, to me, weak low pressure to our north and marginally weaker than normal high pressure to our south. Wouldn't result in anything of interest I'm afraid. Just as well that these longer term models have an awful long way to go before they can be taken seriously

 

[feb1991blizzard]

To add to Steve's post - not only is it very good hemispherically and would send the *** through the floor, there would be a realistic chance of some really frigid air actually reaching us in the first half of November, with potential for significant low level snow.

[knocker]

29 minutes ago, LRD said:

That's an anomaly chart though, isn't it? So that would suggest, to me, weak low pressure to our north and marginally weaker than normal high pressure to our south. Wouldn't result in anything of interest I'm afraid. Just as well that these longer term models have an awful long way to go before they can be taken seriously

 

Yes but not entirely. Superimposed on a MSLP analysis.which you can read in the normal way

[bluearmy]

2 minutes ago, knocker said:

Yes but not entirely. Superimposed on a MSLP analysis.which you can read in the normal way

And the MSLP at that range for a long period will pretty well always revert to climatology with an Iceland low of sorts 

[knocker]

1 minute ago, bluearmy said:

And the MSLP at that range for a long period will pretty well always revert to climatology with an Iceland low of sorts 

Indeed ba but i didn't post this originally/ Just trying to ensue that there is no misunderstand vis the anomaly

 

[Mike Poole]

ECM 12z mean at T144, pretty much guaranteed height rise into Greenland:

And T240 keeps the vortex under pressure with the body of it squeezed over to the Siberian side.

[knocker]

The EXT EPS not dissimilar to the GEFs with the European high ridging norh west between the TPV and the Atlantic trough

[Frosty.]

Tonight's Ecm 12z ensemble mean, apart from a more unsettled spell across the far n / nw later next week suggests quite a benign / pleasant late october, especially across southern uk, pretty much like the operational really.

 

 

Edited October 18, 2019 by JON SNOW

[Mapantz]

1 hour ago, feb1991blizzard said:

 there would be a realistic chance of some really frigid air actually reaching us in the first half of November, with potential for significant low level snow.

That is just hyperbolic, fantasist hope-casting and should be in the ramps thread.

[feb1991blizzard]

3 minutes ago, Mapantz said:

That is just hyperbolic, fantasist hope-casting and should be in the ramps thread.

Look at the cold pool building to the East.

[Met4Cast]

Maybe the cold model output discussion thread should be brought back given people are getting grumpy about other people looking for early cold/snow..

This is a rather incredible late October chart

[Dancerwithwings]

24 minutes ago, Mapantz said:

That is just hyperbolic, fantasist hope-casting and should be in the ramps thread.

Come again, nowt wrong in fantasist hope-casting.

 

Sorry, just a little light humour while we are awaiting Winter  

Edited October 18, 2019 by Dancerwithwings

[Mapantz]

2 minutes ago, Met4Cast said:

Maybe the cold model output discussion thread should be brought back given people are getting grumpy about other people looking for early cold/snow..

It's nothing to do with being grumpy, it's to do with an outright, Daily Express esque post a user made. There's nothing in the model output to suggest significant low-level snow in the UK. It's ramping at it's finest, and we have a thread for it.

Edited October 18, 2019 by Mapantz

[feb1991blizzard]

Just now, Mapantz said:

It's nothing to do with being grumpy, it's to do with outright, Daily Express esque post a user made. There's nothing in the model output to suggest significant low-level snow in the UK. It's ramping at it's finest, and we have a thread for it.

I did not say that that particular chart showed low level snow - read the post again, i said it could be by mid November if we were to get to that 240 chart.

[Mapantz]

Just now, feb1991blizzard said:

I did not say that that particular chart showed low level snow

I know you didn't. However, you still referred to significant low level snow, which, as I said previously, is tosh.

If you want to continue with those misleading types of posts, do so in the ramping thread.

End of conversation.

[Met4Cast]

The EC mean is showing quite a signal for northern blocking towards the end of the month so confidence is certainly increasing.

A little too early for the UK to really benefit in terms of cold/show however the impact on the vortex could lead to something more interesting down the line, it'd be nice to see charts like this verify and have continued early attacks on the vortex before it even gets to develop fully. I much prefer front loaded winters! 

Edited October 18, 2019 by Met4Cast

[Wilxy]

Oh dear its getting a bit frosty in here tonight! Never understand how an argument can occur over weather, can't we all just get along in here!

Some nicer weather showing for next week according to the ECM, which is a welcome relief from all the rain that has fallen recently. 

 

 

[booferking]

 

18 minutes ago, Met4Cast said:

Maybe the cold model output discussion thread should be brought back given people are getting grumpy about other people looking for early cold/snow..

This is a rather incredible late October chart

Like that type of chart are they behind pay wall?

Edited October 18, 2019 by booferking

[booferking]

Relatively cold uppers within touching distance of Scotland on the last ICON run.

[Geordiesnow]

Some movement away from any polar maritime airmass to a classic based NAO with height rises too far west over Greenland with the potential for some mild southerlies to follow, if this was January it would be a kick in the teeth for cold lovers.. It be interesting too see how the pattern does develop as cold air is not too far away so a colder outlook can't be ruled out. 

That said, a small blast of chilly air for Sunday and into Monday, not sure how frosty it will be as there might be too much wind and cloud amounts could be an issue alsom

[Jordan S]

ECM showing perhaps some Frosty mornings in some places early next week but decent temperatures by day then as the high pressure moves southeast to the near continent dragging in quite warm air from the southeast then building to the north of the UK keeping things largely dry warm by day at first but perhaps some foggy mornings then temperatures turning cooler by day 10 so output will likely change although reasonable agreement between this and the gfs. 

Edited October 18, 2019 by jordan smith

[feb1991blizzard]

Snow showers for Northern Scotland.