SnowenOutThere

Should mention "hot and heavy" is still in the context of this storm's version of it. Though it will definitely be pretty as it falls.

For posterity heres all of that condensed into a snowfall map for my friends (sorry MD crew).

Alright let's do this one last time. One final real analysis post before it becomes nowcasting time. Firstly, lets go over the whole progression that got us to this point. Feel free to skip past this part if you just want updates! 5 days ago I made my first post where I lamented over the low out west getting stuck leading to thermal issues over us. It's important to note that initially we were relying on the shortwave after our current storm to induce cyclogenesis. I will give myself some credit as I correctly identified we needed to get our low out of the Southwest ASAP (though admittedly, I was still thinking of the second shortwave). By Monday the guidance was split over if wave 1 or wave 2 would be the trigger for the storm. Last Monday's 12z Euro this quite well as it had our wave get shredded to pieces before wave 2 tried to help out. Notice how this is for Saturday 0z, hence why this storm was initially progged as a Friday-Saturday storm. At this juncture it was pretty clear we had to get wave 1 to be dominant over wave 2 (or run out ahead of it) to get a storm. Luckily, over the next few days that is exactly what happened. We got the double positive of wave 1 speeding up and the mess of energy entering the west slowing down. Another thing we needed (identified Tuesday) was to have the incoming velocity be both more negatively tilted and further south (as it would encourage our wave to gain latitude). The difference between the 18z Nam 12k on Tuesday and its 12z run today shows just how positively almost everything trended! We have a further east wave 1, generally slower wave 2, more N/S orientation of wave 2, and more energy displaced south for wave 2! Look at how our shortwave responds by actually gaining a tilt instead of flattening out! Tracking the evolution of this storm has been a reward by itself as it really shows just how many things we need to go right to get snow. Of course, the real reward is the snow itself. So with the history out of the way what is left to forecast? Well, at this point the synoptics are in place and we have our last real useful runs before this fully transitions to nowcasting. That said, lets draw some attention to the start of this event. Another piece that has trended better overtime is how quickly we can fully saturate the column with moisture (namely as a stronger storm means better wind direction and speed to advect moisture into our area), as the initial atmosphere is extremely dry (see sounding at 7pm tonight) Luckily as mentioned above we have strong winds from around 850mb up to bring in moisture from the Gulf! However, this alone would not really get us anywhere. This is where the real exciting part of this post comes in! 700mb temp advection and frontogenesis! I'll be honest this part is extremely exciting to me. Take this Nam snapshot at 1am tonight of temperature advection in the 700mb layer. Look at that strong temp advection in the 700mb layer! That's how you bring in moist air! As a note, this is better than its 12z run hence the improvement in snowfall totals. What this then means is this storm looks to come in hot and heavy with a good thump of snow via 700mb frontogenesis (once the column fully saturates ofc). This is shown with the NAM sounding at 1am as you can really see the lift this provides for 850mb up past 500mb (which includes the DGZ btw)! One other thing I want to note is a maximum that shows up with 850mb forcing right over the NOVA area at 9z on the Nam (and to a less extent the HRRR) I do wonder if this holds true that someone in that zone could have a mini jackpot. (A counterpoint to that is that the DGZ is still above 600mb but honestly I don't know how that interacts with lift in the 850mb layer). From here on out I'll be looking at the NWS analysis page to see where the best frontgen ends up occurring! It has truly been a joy tracking this event with all of you. Being honest, University wasn't all it was cracked up to be (in some regards I still like it overall!) so your kind words were appreciated. I also want to thank everyone who's posted meteorology analysis before as those contributions are what got me to make this thread (even if years removed from the advice given). My advice for any poster who wants to learn analysis is just look at the 500mb maps and try to figure out the connections of vorticity for what makes a "good" and "bad" run as that should get you started thinking more upper-air based. Thank you all again (especially @Terpeast @WxUSAF @psuhoffman @CAPE @Eskimo Joe and the posters I'm forgetting from this list (sorry!)) for helping. Hope for snow.

WWA hoisted to include both metros. Lets reel this one in!

What ratio would you advise using instead of Kuchera for this event

Congrats and good luck! My sister was born during the 2002-2003 winter (or the "one where it snowed a lot" as they call it) and my parents have similar stories. I'll try to be the intern filling in for your absence posting wise!

Wonder if that mini supercell alley is a direct result of the gap in the mountains I-64 takes impacting the flow. As for pictures I already have my d850 charging and ready to go. I think I plan to get the class Rotunda Pic, Dell pictures, and various Garden pictures. If you have any other pretty snow picture spots on Grounds please let me know!

Do you know any resources I could use to see and possibly anticipate how much down sloping to expect (besides annoying my resident professor on microclimates which I plan to do)?

What would you expect for Charlottesville? I'm thinking that at least an inch is a safe bet with a max of 3 (1.5-2 is my target). Only worry is down sloping or a further slip south (though with the H5 that would be quite a change to skunk me) but generally I think I'm pretty locked in for a pretty Friday morning on Grounds.

One last post before I call it a night. Something that I thought was a fun demonstration of how moistening the atmosphere truly works was this snapshot of the HRRR at 2am Friday. I really love how you can see the actual snowfall hitting the ground earliest along the spine of Shenandoah because the couple 1000 feet elevation they have compared to the surrounding areas means that there is less dry air between the clouds and the ground. It's fun to then see this reflected by it showing snow hitting the ground instead of sublimating. Dewpoint depression shows how the higher up you go the more moisture is making it to the surface as the lower values are found almost identically to an elevation map. None of this actually has a sensible impact on our weather or forecasts (though it does explain that the Shenandoah maximum in this storm is less the result of orthographic lift but instead this dry air quirk) but instead just a fun exercise to show how moistening the column works from the top down elevation wise. I will be sure to this run to show my mountain meteorology/climate near the ground professor as I feel that they'd appreciate it.

FWIW the RAP is pretty juiced

The one thing that annoys me about the HRRR is how the best forcing arrives with the precip (which makes sense I suppose). However, according to the soundings we have an entrenched layer of dry air (someone pointed this out earlier) which would sublimate before it could be saturated. HRRR shows this taking a couple hours which would be painful (though another actually smart met will need to chime in on how much that matters in relation to its molded snowfall output or if its factored into it). The good news to my eyes is once the column does saturate its game on with a saturated DGZ and good lift aligned with it! I know @psuhoffman mentioned that strong winds in the DGZ can break apart crystals but from my (admittedly chatgpt) understanding this soundings seems fine in that regard.

To illustrate the 0z run has the higher heights in front (notice how there is less confluence in Maine compared to 18z) which helps the storm amplify. Secondly, the shortwave itself is a bit stronger and less stretched out as the NS "kicker" is further south which almost seems to help spike development in our shortwave (while having the benefit of kicking it east slower) 0z 18z

H5 looks better too with a stronger shortwave out West and less confluence allowing that push northward with the precip. Don't know if it'll actually translate to a huge change but encouraging regardless

I'm taking calc 2 next semester so I may be pinging you quite often for help (though seriously if you tutor people I'd be interested depending on how my first exam goes) Physics will be next year for me and I cannot say I'm looking forward to it.

Lowk aced that test now all that’s left to do is reel in this storm

Thank you! Honestly, it’s just dense concepts but once you understand them they connect pretty well to being applied. Unfortunately meteorology isnt the only class im in so imma need some prayers while i take my chem test in the next hour (which all of my posts over the past 3 days have been a form of procrastination for)

Hey we all make mistakes. Besides, you're a way better poster than I was in my early years of high school (as some on this forum no doubt remember).

I would encourage everyone to get into this side of reading storms as its way less frustrating than just tracking seemingly random movements on the surface as you can tell what a setups potential is more concretely.

I’m coming at this from the perspective of this setup was never really supposed to snow and it was only yesterday it even became a possibility due to out west trending better and emphasize shortwave 1, In a lot of ways it’s more practice than anything. Though I can’t lie and say my mood isn’t boosted by being 100 miles south of most posters.

Hopefully the GFS run stops the downers from taking over the thread

Hey I lived in Nova so I gotta cover the VA public schools as that’s where nearly every single one of them went. If you have a map that includes MD I’ll happy use that instead thougu!

First stab at a snowfall map (made for my instagram but might as well post it here). Since it's made for public consumption I always hedge my bets a bit so its a bit more conservative than my true thinking.

Euro has more confluence over the Northeast so its worse than its 6z run. That said, its so close to being something better as a more relaxed flow is only off by 24 hours.

Yes, but unfortunately that is around .1 of actual qdf! The general synoptic pattern is locked in so now we just get to see how exactly it plays out.