SnowenOutThere

I started a thread for future analysis of the storm as you guys have a better shot than the main focus of our subforum

Howdy! I started a main thread for this storm as it also impacts some posters out in Central/Western VA if you want to post there as well.

This is also a great test case on if starting a thread ruins an event as if this manages to completely fall apart within 12 hours of the start time the curse may be real.

Done, please pin it!

As @WxUSAF pointed out this is now a legitimate enough event for the southern folks to start a thread specifically for it! Let's try to will this thing a little bit further north to get it to everyone.

GFS lowk joined the party with its 18z run

Hey, we will always have women's swimming at least.

I did later check that and the 850mb lift is pretty crazy. Though I guess it could be onto something with the cold air press from the north? I don't quite have enough skill to understand it yet though. Either way the soundings for Cville as it snows has a pretty large and 90% RH DGZ layer with lift so I should see some nice flakes. Though lmao

What the hell is the 12k 18z NAM on because if I get even half this total I will follow @Terpeast and eat a shoe

Had to make a forecast for my friends so I had to take a stab at a snowfall map and came back with this.

Yeah I think a chase should be reserved for either 4+ inches or a weekend day. Not to mention how bad the traffic is getting into Cvill from the 14 lane stroad on route 29. I hope its able to bump its way a little bit further north for you guys as well! So far our seasonal trend appears to be last minute favorable north shifts so its possible!

This wasn't even really on my radar till you mentioned it still Friday night. Now I need to make a last second insta forecast for my friends at UVA Tech and W&M lmao

Euro with a bit of a jump north

I tried analyzing how those like 15 NS interactions would impact a downstream storm and all I could gleam was this:

While the ridge is a bit diminished I think its more so the NS is just completely different around hours 105 which I don't think helps us out.

So what I'm hearing is that I'm the Curry of HRRR extrapolations? Should put that on the wall and in my signature tbh

3k NAM is going to make a significant jump north based on the confluence at hour 30. That said, it was a southern outlier at the 18z run but should help @Ephesians2 out

I mean assuming I got the positive changes from 18z to 0z right at hour 15 (also couldve been an unrelated factor) that is technically the HRRR's wheelhouse? Or am I insane?

Zoomed in map with pretty much all snow done at this point

18z

Thank you! To be entirely honest knowing which model solution is correct goes beyond my forecasting ability as I don't know enough about the synoptics behind storm formation yet (though I am trying to learn). However, I am generally able to identify which runs are better and why in relation to synoptics. I think the main way that the Euro develops the storm to be weaker lies in it having less favorable interactions with the low pressure up north. Looking just at the GFS to Euro we can see the GFS gets the ULL out of the northeast slightly faster so there is less connection between the waves. The Euro on the other hand keeps it a little slower with the northern ULL so there is more suppression and reduction in actual ability to form a low. Though as I said before this is getting to the end of my knowledge so take it with a grain of salt.

Just now realizing how delusional it is to truly be trying to extrap the hour 15 of the HRRR its like this

So far (and this is borderline delusional to say) I like the changes that the HRRR has made through the grad total of hour... 15.

With the 0z HRRR running for the Monday storm I'm going to do a quick breakdown of what we want it to show (as its 18z run was by far the best we've seen for us). I will be comparing it to the 18z Euro. So starting out early in the run the first appreciable difference is that the more northern parts of the shortwave (plus the northern crusher) are weaker compared to the Euro. This helps our system out by allowing it to consolidate a bit more rapidly in the plains which in turn allows for an earlier amplification period. However, the real difference is in the confluence up north. The Euro has this running across our northeastern states. The HRRR on the other hand has it around 50 plus miles further north keeping the confluence located more in Canada and less across upstate New York. This obviously gives our storm a bit more room to breathe. So as the 0z runs its going to be important to see if it maintains these positive aspects. Additionally, it gives us a reference for how the setup would need to look in order to get snow into the subforum proper.