MillvilleWx

I believe the GFS runs on the FV3 core and is fairly hi-res compared to what it used to be. RGEM runs at a resolution similar to the NAM with the HRDPS the Canadian version of the hi-res 2.5km, although it has some significant issues with a multitude of parameters. This is a great question for the MDL people since they have more of the background.

Under no circumstances would I have put out a map that looks like that with those ranges. I've made these decisions before for these types of maps. This is honestly a no-no. Ugh

70kt 85H LLJ aimed right at them doing the trick. System is still very dynamic in its structure.

Storm looks healthy so far via the 00z NAM. Man, NE Kansas is going to get the business with this storm. Sheesh.

Yup! This is the stage where if we see any deviations from the norm, it would be now with the introduction of the CAMs. The D3-5 period is pretty boring typically on the NBM with regards to changes, I've noticed unless there is a noticeable shift in the general synoptics. So far nothing shows that at this lead. Appreciate taking the top to pop in and give some low down on the model background part of things @high risk I try my best, but you and @dtk are more well versed than I on the inner workings of most, if not all relevant NWP.

1/3/25: 0.3" - Snow squall that lasted 10 minutes. Non-accumulating snow prior and just after. Snowed for an additional 30 minutes afterwards, but little to no accumulation.

The NBM is a very useful tool for forecasting when you know how to interpret it and understand its biases. I've been keeping an eye on it and it's been pretty great with handling the swings and limiting the crazy max/min variance from run to run the past few days. It'll be interesting once the CAMs start getting incorporated. That will be a useful way to seeing some of the proposed banding being forecast.

Most of the snow occurred here in a 10 min burst. A nice little appetizer before Monday’s main course.

0.3” here in Edgewater. Was having dinner with the wife in Annapolis and it was raging for a period. Everything solidly covered.

Moderate to borderline heavy now in Annapolis. That escalated really quickly

Light snow in the Annapolis area. Pretty!

Even then it looked pretty good. Shows the dual maxima as well. Can’t say I’m upset by any of these latest runs.

Yes, sorry for any confusion! MD32 to be more specific. I’m still waking up. I laid back down for a little more sleep and woke up to my spidey senses tingling.

This type of setup is one where you can still cash pretty good despite any flip to IP. I feel the WAA regime will likely provide some pingers to areas as far north as Rt32, but it could be brief before the thermals improve with the CCB takeover as the surface low off the coast matures. The 5H/7H vort pass is becoming important, but the good news right now is that is becoming increasingly favorable for the region. There will be 8+” totals from this for several locations as I mentioned early this morning before I left work. I will continue going on the record mentioning that there will be dual maxima in this setup with one likely along and north of I-70 and another between I-66 and Rt32. Very impressive dynamics at play as progged. The chances for WSW snowfall is improving incrementally at this juncture. There would have to be a very hard shift in order for the region to fail completely. The players are all on the field. I feel 00z is when we will start seeing less spread and tomorrow evening is when we can start parsing more intricate details. It’s gonna snow y’all

Just a heads up, but that map is very very rudimentary and only takes into account what could be the predominant Ptype for the 24 period. That is also not an exact science. It’s a quick and dirty way to put precip forecast on the map. Typically used as a glance for public and people just wanting something very quick to look at which you would be surprised the higher level people that end up seeing that map.

I have some thoughts on the storm after analyzing some overnight trends and digging deeper into things at the office. I will have more input with a longer, informative post after I assess the 12z runs later today. Heading home for some sleep. I want to leave people with this: There will be several spots I believe that see 8-12" of snowfall from this somewhere along and north of US50. This is a small call on my part early on and I have a hunch the 12z runs will maintain my thought process. A couple models this evening are trending in that direction. See you guys later today!

GFS seems to be on an island with its evolution. Will take a look at ensembles to see how they behave, the rest of the 00z suite looks absolutely nothing like it. I know this is a broken record, but people have to stop living and dying by every model run. You will drive yourself crazy. CMC coming in for a major beat down and follows the rest of the suite with its 5H evolution. Everything still looks fine by my eyes. Back to QPF forecasting for me. Will chime back in after 1230

Reston is typically on the dividing line, so I feel you there. I'm going to be in Edgewater, another area that walks the line. It will be pretty close in our hoods. I do feel we see some sleet in this at both our locations, but it will not be long and we'll get thumped with the WAA pattern, then flip back for some CCB fun to round things out. We'll be okay (Famous last words )

The warm nose will be pretty pronounced thanks to a very strong 85H LLJ. There will be a northern edge to said jet, however and that should hit the proverbial wall somewhere in the customary spot. Down by your hood, the issue is the depth of the cold is not nearly as primed compared to those north of I-66. You can see it in the 850mb temp profiles. The cold there is much more shallow, but it will be hard to scour out. Pending the speed at which the precip edge arrives, some snow is certainly plausible before the eventual flip to sleet and eventually ZR. I would be worried for areas south of CHO for ZR in this one. Blacksburg area up to Harrisonburg look like a rough spot to be in. I'm sure the jet will promote a period of mixing a little north of where I expect, but the hot and heavy thump of WAA snows will be significant, and that will offset some of the hurt before the CAA regime takes back over with the CCB and we finish we 1-4" of pure fluff before we bid farewell to our system. Sometimes you gotta smell the rain to get the heavy snow in these parts

Blanton's is wonderful! Did you get their customary bottle, or did you splurge and get the Gold Label? The single barrel is so good, but the Gold label is top 3 I've ever consumed. Incredible

You are most definitely not a clown! The reason I know that is because I'm a clown, and you're never at any of the meetings

It's the 84hr NAM, so we can usually take with a grain of salt. There are some elements I did like seeing on the run, however that should be really solid for our hood. Take a look at the 7H VV panel on the final frame. This is indicative to some incredible lift areawide that coincides with the heaviest QPF being advected southwest to northeast. This is literally how we get those classic WAA snows that overperform in our hood. The antecedent airmass is COLD leading in and remember, the 12km isn't the finer 3km resolution from the Nest, so it could be skewing the warm nose a little more in an areal sense. There will be a warm nose and there will be a shift to sleet for some, but just have to remember climo. Where does that usually occur? If you're out west of US15 and north of I-70, probably not much to worry about. South and east of there, there COULD be a short period, but this system is leaning towards a very dynamic vort pass and surface reflection developing off the coast. That potential CCB to round out the storm would likely develop in this case if you took what the NAM was spitting out, verbatim. Just look at this 700mb panel for VV's with the 7H contours overlaid. Look at the closed 7H reflection to our west? Any flip to sleet will not be a long standing issue and the shift back to snow will occur. I didn't see much to hate from this run, NAM not withstanding. Let's move on

This is going to be part of some surprises, me thinks. These dynamic systems always seem to have elements that don't get solved or sometimes not even seen until it's happening.

That ECMWF dual banding structure is literally so textbook. There will be some impressive amounts with this one so long as the synoptic pattern holds firm. The WAA snows could very well come in like a wall. This is one of the best way we score around here.

Moving this to banter, but yes, it's kind of crazy that they haven't had an event break 12" in so long. They got tons of sleet and ice storms in that area of the country. They will be right on the line of the transition for this one too, but I hope for historical sake they can hang on to snow the whole event. Would be something to remember and tell stories about for generations to come.