Jump to content
Will it snow? 7 day forecast Weather Radar Will it be cold?
Snow?
Local
Radar
Cold?

lorenzo

Forum Team
 View Profile  See their activity

  • Posts

    4,875

  • Joined

  • Last visited

  • Days Won

    25

 Content Type 

Posts posted by lorenzo

    Stratosphere and Polar Vortex Watch 2020

    in Spring Weather Discussion

    Posted

    3 hours ago, Garthvader said:

    Hi all

    Complete novice at weather models,charts etc i have a bit of an understanding of the models and charts and very limited understanding.....anyway just wondering if anyone could help out and post the chart or link that shows the temperature increases of the first/secondary/combined ssw....

     

    Thanks again if nobody can be bothered with me ...... understood   

    Peace out!

    image.thumb.png.c43ff9b9c0c153e3d660d78d71945681.png

    Charts located here 

    6554b6be8c0d829a8bf63ae0c82cf121_link.pn Data Services

    ACD-EXT.GSFC.NASA.GOV
    Available annual Meteorological data

     

    Also tend to see this one a lot in various places.. 

    6554b6be8c0d829a8bf63ae0c82cf121_link.pn Climate System Monitoring / TCC

    DS.DATA.JMA.GO.JP
    Climate System Monitoring / TCC

     

    image.thumb.png.9d0bf5b26c3ed3bd73b69a0307c8b253.png

    • Thanks 2
    • Popular Post
    • Popular Post

    Model Output Discussion - Snow for some, but what else is in store?

    in Forecast Model Discussion

    Posted

    12z Friday is one staging point then looking 'above' via strat plots this is really progressive from the 18z, not progressive as in it's the pub run doing outlier stuff, but more to okay what is is seeing as the NPAC takes effect.

    Friday 12z was the date I had pencilled for some 'settling' of the immediate SSW dynamics, then Tuesday - Thursday next week ( see strat thread gifs) for further ahead.

    The adage of compare 00z to 00z and 12z to 12z I get, but as we exit the initial chaos of the SSW each run heralds clues.

    The model watching folklore shout out I would call this week is the what the 00z takes away the 12z gives back ( whether this is due to the 12z being the fullest suite of data for NWP delivery - not sure).

    All in - patience folks - we have been served an SSW on top of some great blocking teasing things, we know SSWs main artefact is dissipation of cold and sticking to that evolution will temper help - hell we all want a holy grail 09 instant response, but lets just watch this play out. Think of it as you pressed play on the next run coming out, but you are watching it at 50% speed..

    image.thumb.png.acc9646bfc0b2a0e3cf220c5e5bc6a38.png

    • Like 44
    • Thanks 2
    • Popular Post
    • Popular Post

    Stratosphere and Polar Vortex Watch 2020

    in Spring Weather Discussion

    Posted · Edited by lorenzo
    Deleting additional chart added in error

    The GIFS I posted above hopefully help a little in terms of what is being modelled currently, I wish I had all the answers !

    The Berlin GIF above shows the core of the vortex shifting to the Siberian side at 10hPa and in doing so it becomes coherent again, interesting dynamics as it is almost magnetic in absorbing the Greenland Daughter Vortice, in doing so this whips across the Atlantic. Thereafter, the US side of the hemisphere appears drained of core vorticity. Granted this is higher up in the strat and a longer term direction of travel, also how does this imprint into the troposphere remains a question.

    Then the other GIFs further down, see the hPa labels show just how chaotic this process is in terms of that same transition, the energy which has vacated the Greenland locale at 10hPa is still 'active'. Hence, the singular slide for Tuesday where it would appear wave breaking maxes out. 

    This makes working out what is next massively difficult and will defer to experts on Twitter for views here in terms of latent impacts.

    D10 @ 10hPa

    image.thumb.png.8ce7a62b453dcd8df5959c970696471c.pngimage.thumb.png.b24dadf27486747d17779ab1785246eb.png

    D10 @ 50hPa

    image.thumb.png.9bf82d4695c9e4b461093461ada6bf8b.pngimage.thumb.png.7446ffbe9a22f28bfd21f1bddb0d1317.png

    D10 @ 100hPa Berlin / d 5/7/10 @ 250hPa NASA

    image.thumb.png.d5b55ef62ddfabd11911b06cee86e7a8.pngimage.thumb.png.636d47cd71193c382f3e0aa932e4a126.pngimage.thumb.png.a33103f15b14c5e2fa9cb3c83dbc1ccf.pngimage.thumb.png.681453def24323cdcf00d1e46af2fef8.png

    The last series is clearly quite chaotic as energy transfers beneath the block and we can see the alignment somewhat in the NWP model output. 

    If the longer direction of travel is for a picture to develop where we see the 10hPa and 50hPa profiles eventually imprint on the troposphere, well - one can imagine. A big avenue for a block and a mass of cold to tap into. The vortex regrouping at 10hPa as per above will also account for the reasonable / strong recovery in u wind which some may look at to say, oh well that's the SSW done with.

    Here is the warming profile and zonal wind profile vs deviation from previous 60 day mean, and I think they show the 'slow-motion' transfer down the column of the SSW.

    image.thumb.png.adb4c538414ff9882c996f8112b01c81.pngimage.thumb.png.03e835e6c1f7d4b05364e600805e1a89.png

    Looking at all things considered, the daughter vortice - it's disruption, how quickly the energy transfers to the larger vortex are a great example of why it's all a good watch as another 'flavour' of SSW unwinds. We know to expect volatility in output and hopefully the above kind of outlines why to some extent. Hopefully some others can join in to add further insights. It is a monster W1 and remain hopeful we will still be seeing impacts lagged for some time. Right now in conclusion it is just too difficult to call with certainty. It's a new SSW and still learning from it.

    image.png

    • Like 15
    • Thanks 5
    • Popular Post
    • Popular Post

    Scotland/Alba weather discussion - Jan 2021 onwards

    in Regional

    Posted

    18 minutes ago, Benvironment said:

    Thought I heard thunder outside......but turned out to be eight cows that had escaped the barn and were running around the farm. I can therefore confirm yes, it is snowing  About 1cm on the ground....which was extremely useful for working out where said coos had gone

     

    Thunder Cows.

     

    Nice !

    • Like 17
    • Popular Post
    • Popular Post

    Model output discussion - cold spell approaching?

    in Forecast Model Discussion

    Posted

    4 minutes ago, sheikhy said:

    Aaahh the good old pub run!!only to bring us back down in the morning!!

    Yes, normally but now we are on the cusp of the models beginning to get a handle on huge dynamics brought around by the SSW. These are throw the cards up in the air ( warmly) events...

    This shows the variation in temperature vs previous means and we can see clearly where we are currently vs projected disruption, the 06z GFS also delivered an AO cranking in at -6SD, totally agree the Pub Run is fun and games, this time it is probably on the envelope of what could coherently lie ahead.. Initial chaos may smooth towards Friday and things become clearer. 

    image.thumb.png.768f37348baa9921e6fe832041b6aed4.png

    Models just are not up for dealing with these dynamics and this is why patience is required, there is no golden x =y in strat warming events, there are some clues of good connection to trop. impacts as I see it from tweets by Hannah Attard ( further coupling exists)  and Amy Butler ( where does the vortex energy split), this is probably the best week of model watching anyone can examine for many a year. What we do know is that this is a significant SSW and the effects / artefacts will be felt for some time.

    This for me is the watch point - the nuances in the break 5 days - literally every model has varying degrees on how it sees this, manifests lows, manifests phasing etc.

    That aside and longer term we do have our old winter wild card the MJO waiting in the wings to enter stage right and continue to reshuffle the deck.

    image.thumb.png.908d53e1c20109746347b72708f809b1.png

     

    • Like 32
    • Thanks 5
×
×
  • Create New...