lorenzo

January 6

Read the room EC for goodness sake...

Am not buying this run re: the 150hPa and 475K profile, I think it may be retaining too much energy in the Canadian daughter vortice. Still, it goes without saying, you really need the EC to align to have any sense of confidence in direction of travel.. doubt any of us would bet against it. Let's hope it's having it's own wobble 24 hrs after the US counterpart did.

January 6

2 hours ago, Fiona Robertson said:

Thank you! Fantastic links. I thought I was imagining things. If the vortex splits is it usually top down or bottom up?

The vortex can split at differing levels if elongated; top down warming can occur which may preclude splits happening lower in the vortex. Tropospheric led splits at lower levels are pretty much what we all like to see - given the notoriety of the 2009 SSW. Rather than top down or bottom up - we tend to view things as either displacement or split events impacting on the vortex.

January 6

Icon-ic...

January 6

1 hour ago, Fiona Robertson said:

I've done this as a separate post cos I am a numpty when it comes to editing posts with an image in. I marked the centre of the area of circulation in the image above, it's way towards the right,to use as a reference point andthen I cycled through the various altitudes. Images are 70 hPa, 250 hPa and 500 hPa. Notice that at 70 hPa the centre of circulation has relocated, but the overall elongated shape remains. At 250 hPa, the elongated shape remains, but there are now 2 distinct areas of circulation, one on the left, one on the right, but the centre of the one on the right is in the same place as the 70h Pa one. At 500 hPa same thing.

What point am I making? None, it's more of a question or two. Is the polar vortex tilted, ie is the top of it being pushed over by the warming high? And is the warmer area to the west of the UK at 500 hPa pushing into the vortex from a lower altitude.Tomy completely untrained eye it appears that the big area of warming is elongating the vortex and then at lower altitude the vortex could be split and the split propagate upwards?

You are looking at the right things - yes.

To save you some work this site may help give a sense of the tilt in the vortex brought about by the Wave 1 forcing on the vortex. This links shows the tilt across the vortex structure vs height.

StratObserve Vertical Vortex Structure

STRATOBSERVE.COM

The 3D view is also a great visibile representation.

StratObserve 3D Vortex

STRATOBSERVE.COM

And finally, an easy way to view across the pressure levels from the Berlin site

Institute of Meteorology - Working Group Atmospheric Dynamics - ECMWF 240 h forecasts January 05 2024 12 UTC

USERS.MET.FU-BERLIN.DE

January 6

Added some analysis of recent progressions in the old strat thread as would just get lost in the madhouse. Plus a few from the 06z below..

January 6

Given the pace of the model thread jumping in here to add some output, almost too much to look at right now given NWP output, Strat Output, MJO in play and AAM turning the corner.

First off picked the 30hPa level given the top of the envelope projections shown in Merra for a couple of variables driven by the strong W1 warming.

Lovely view of the progression of the warming and the impacts on the vortex as it distends and is split.

Also viewable as animation here , graphics not as great - but does highlight another pulse of warming out at D10.

Then the 100hPa look which is probably the most exciting one currently in terms of echoes to NWP and what is driving chaos and variability.

Vortices splitting at just 72 hrs and the energy shearing from the Canadian lobe spirals south - whipping across the Atlantic. The Canadian lobe pulling back, whilst the Siberian lobe progams the Northerly regime. Interesting to analyse these views as the exchange of energy between the daughter vortices provides neat insight into what may translate into NWP.

It is a delicate balance of separation from the split in terms of how the vortices interact. Friday update saw only brief separation and energy transfer from the parent Siberian vortice back to Canada - reinvigorating the aforementioned filament and placing further pressure on the ridge attempt into Greenland, so much so in fact - it looked to be heading to a Scandi solution before getting stuck halfway house in the 'no mans land' which leaves us looking at less than appealing from a cold perspective output.

This break is far from resolved yet and given it is happening within next 72 hrs, twists and turns to come.

In relation to the MJO - beginning to look more coherent and composites show the direction of travel imprinting, it is never a=b for these so use as guidance, last updated in 2014 so nearly a decade of data not in them.

A vortex already heavily assaulted this winter, technical SSW or not - it feels as good as one currently, with more duress ahead. Wondering if January is just an appetizer for February as AAM rebounds..

Finally a look at the development of the blocking regimes from Xmas Eve to date from EC as we progress from nowhere to the stuff we all like to see from a cold ( and dry) perspective in Winter.

January 6

If we don't have snow (yet)... Then this has to be the best weather, everything frozen, blue skies.

January 5

Beast from the errr .. West..

Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4997207

January 5

Got to love the pub run when it serves up one of it's specials, utterly bonkers.

We eventually end up with another low pivoting in from the west too - a run where the floodgates open.

Very difficult to qualify this given the extreme solution offered, sadly one likely for the shredder, amusing nonetheless to watch.

@Ravelin Hopefully you haven't jinxed anything and it was the tyre booking that helped the stars align. Prelims done already in West Lothian, so strange Scottish schools have a) weird holidays and b) so much variation in what they are all doing at different times..

January 5

Beast from the errr .. West..

January 5

18z serving up the Friday night madness..

January 4

Stronger looking heat flux evident later in the month.. an already weakened SPV under renewed attack..

January 4

A much happier model thread currently... and, neither wonder.

Some tantalising cold output pulling through, GFS below for mid-month..

January 4

1070hPa over Greenland, menacing TPV to the East solidifying an already frozen solid Scandinavia, Europe directly into the freezer, ruined Vortex.

Delightful !

January 3

Found this date lurking in the CPC analogs and a fellow kiltie and Ian have already done the ground-work, interesting read..

January 3

Some cold model nirvana around on the 12z GFS tonight for mid-month

Omega / Oppenheimer

THE OMEGA BLOCK

WWW.THEWEATHERPREDICTION.COM

January 1

Happy New Year everyone - wishing you a healthy and happy 2024 filled with good fortune and a lemon ton o Snaw

December 31, 2023

Just spotted this on twitter for 30mb...

December 29, 2023

This is a new look for the break..

Well it is the Friday 18z - ( the Saturday 00z and 06z are usually absolute dubiety- 12z to 12z is the way to go for Friday into Saturdays ( years of wondering WTAF) )

December 29, 2023

You know what would be cool - if folks could take it back to reviewing the models, looking at the output, posting up some thoughts.

Importantly, without adding in a layer of spiky thoughts about what others may or may not be doing, or howthey should or should not be behaving, one liners, agendas, this ramp, that ramp.

We have another great period of model watching ahead, excitement is all good. Trolling, sniping, various - that person should be this or that - it's quite boring, and detracts from the quality of the thread.

Take a moment and think if your post would add value to the thread or derail it please.

December 29, 2023

Looking at heat flux anomalies Xmas Day has perhaps a stronger pulse vs Wednesday to consider your original question at the top of the page Nick, not sure if this answers in full it could in part explain some of the subsequent output.

Still a fair bit of time until the 7th to see how this one plays through. The animation from 00z this morning is neat to watch how the vortex ingests it's New Year shot of Heat Flux, distends and splits.

Weather Maps - Temperature

FLUID.NCCS.NASA.GOV

Fluid provides applications for interactive analysis and visualizations of meteorological and chemical output from GMAO-supported forecast and reanalysis models

Lots of energy remaining over Greenland / Canada still and some chaotic filaments flaying off will make NWP jump around considerably I think.

Whether we do get a technical SSW with the u reversal, or whether we do get to +3 or 4 ms-1 seems almost moot with respect to - it's degraded either way and primed for the next MJO go around. Perhaps the old 1 / 2 needed for it this time round...

December 29, 2023

Nice to be back in the cold clean air, albeit for less than a day!

Looking forward to a couple of hours of sleet tomorrow - whoop whoop !

December 27, 2023

From Fubar news page.. craziness.

December 27, 2023

20 minutes ago, Quinach said:

Never seen the garden as flooded as it is just now - Fubar News has some impressive images of the flooding and wind damage round the area.

https://www.facebook.com/FubarNews

See the SUDS basin in the nearest village has overtopped...

Good page that for updates and highlights how impactful this system has been given the sheer volume of trees fallen, flooding, road closures, breakdowns. Certainly would have warranted an amber warning one would think?

December 27, 2023

Wonder why this wasn't Amber?

Sign In

Forums

Blogs

Gallery

Events

Learn About Weather and Meteorology

Community guides

Posts posted by lorenzo