The Return of the 12/5 Snowstorm

[bncho]

18z EPS shows an even stronger signal than 12z.

[CAPE]

2 minutes ago, SnowenOutThere said:

Thank you! We finally got to the actual H5 Jet stream ageostrophic etc part of my course last month! Of course, it wasn't anything crazy but its given me just enough tools to begin identifying how the upper air connects to the surface. That said, I'm very confident that this is very much a Dunning-Kruger effect where I know just enough to make broad forecasts and identify what I we need models to trend and make predictions from an earlier hour to but I am unable to "correct" model behavior as I just don't have the confidence (wait till Spring 2027 and Synoptic met for that) to do so. So with that said please feel free to correct any mistakes I make as it literally might save my grade!

You doing good friend. I used to be the one to bore everyone with all the 500 mb vorticity interactions/analysis. Now you can do it lol. It's largely what dictates our sensible weather at the surface as you are discovering. Good stuff!

[SnowenOutThere]

1 minute ago, CAPE said:

You doing good friend. I used to be the one to bore everyone with all the 500 mb vorticity interactions/analysis. Now you can do it lol. It's largely what dictates our sensible weather at the surface as you are discovering. Good stuff!

I edited my previous post to give you a shoutout for those posts as they are what got me largely to where I'm at! Thank you for them. BTW the best part about being a student is that while doing these breakdowns is procrastinating it feels infinitely better than doom scrolling as I can rationalize it as learning for future classes. 

[Maestrobjwa]

1 hour ago, CAPE said:

Strong upper jet streak induces stretched/elongated vorticity ribbon underneath. Not going to get a widespread or major event with this, but rather a possible narrow corridor of decent lift that could produce a light to moderate event. Hard to say exactly where that might occur at this juncture but it appears it will be somewhere in our region or maybe even a bit south. Given the h5 look on the Euro it *should* be cold enough for a bit of snow.

If I gambled I'd bet a lot on that being the outcome, lol

[Terpeast]

28 minutes ago, SnowenOutThere said:

To be honest the upper winds is where my knowledge gets confused as we went over how the jet forms (I can tell you why the jet increases on the northward heading side of an upper low and decreases when heading south) but didn't go over the practical effect on the surface. I'm currently trying to research it on my own but generally it confuses me as my intuition says that areas of lift should form where winds are accelerating in the upper atmosphere (as it induces lower level lift as air is pulled into the upper flow) yet I know from the 4 quadrant model that understand I have is flawed. Additionally, I would've expected that stronger upper winds generally encourages cyclogenesis and didn't consider that it could actually hurt consolidation (which admittedly does make sense). Basically, what upper wind profile would actually be conductive to forming a strong surface low pressure? 

Left exit and right entrance regions, where upper level flow diverges. Conservation of mass and surface boundary dictates that air must lift to replace the diverging flow. 

[SnowenOutThere]

5 minutes ago, Terpeast said:

Left exit and right entrance regions, where upper level flow diverges. Conservation of mass and surface boundary dictates that air must lift to replace the diverging flow. 

That makes sense, but as Cape alluded to with the flow stretching the vorticity apart is it best for a developing low to be displaced from the strongest winds? I know that oftentimes the jet isn't able to "round the base" of a trough and once it does it indicates a matured/max developed storm and is that the logic behind it or am I mistaken?

[Solution Man]

Damn, great stuff tonight folks, thanks