MillvilleWx

The CMC is a naughtier version of the GFS. A true forum pleaser

The 7H evolution on the NAM is completely different from the GFS and Euro, and is absolutely nothing like the RGEM. The RGEM develops the 7H low to our south over central VA, then goes bonkers as it pivots slowly underneath us. The NAM hangs on the 7H low out in the OH Valley for a long time before finally transferring to the coast, leading to a late capture and keeping the best frontongen to the north. The GFS/Euro is fairly similar, but one thing I've noticed is the orientation of the 700mb low is very SW to NE, which places the mid-level frontogen just off to the north, leading to NE MD to SE PA on northeast getting slammed. A slight adjustment in the capture and/or a more N-S oriented 700mb low like the aggressive models have could be all the difference in the world in the positioning of the CCB through part of the sub-forum. I will say one thing, the trends so far have been positive, outside the NAM 12km, so keep the faith. If I had to guess, right now the area north of I-70 has the best chance to see the most CCB action with Carroll Co on eastward the highest opportunity. Models still have a lot to figure out and I see this going to the 11th hour.

The RGEM apparently doesn’t want to support American. It wants to bring poutine and Labat Blue to your backyard and have you take pictures with the moose in full flannel .

The consistency of this model has been absolutely incredible. I honestly hope it’s right for the sub-forum. It would be a monster for I-95 DC to Philly. Dare I say, looking....2006ish on that run *Ducks for cover* .

Less than 24 hrs from the onset of snow and the models still have zero clue where the low will be captured. NAM is off Lewes, DE and the RGEM is off Wallops Island. The difference places the CCB from SE PA to Central NJ on the NAM and Philly to DC on the RGEM. Actually pretty remarkable we this kind of discrepancy. Just shows the intricacy of the 85H and 7H lows during the transfer window. 12z Mon through 00z Tuesday is still a very volatile period. .

Hate to say it, but hopefully the NAM’s aren’t on to something. That would be a pretty classic Miller B event for the sub-forum. 40N cash and south is meh. I still like a general 4-8” with local 10” to the north and east of I-83, but the monster totals are likely PA/NJ with this one right now. You NEED the Nam to adjust. It might not be the best for UL handling, but when it’s consistent, it’s a red flag. Was like that in 2016, 2017, 2019, and the last bigger event. .

I would think 2-4”/hr is doable for the max potential, but extended 1-2”/hr is all but a given and it’ll be slow to move. Whoever is fortunate enough to get into the CCB will be puking dendrites for hrs on end and 18-24” becomes more the reality. I like EPA up into Central NJ for that potential, however, there will be secondary maxes away from the CCB due to 700-500mb frontogen as the ULL passage to the south and crank off the coast as the storm stacks. That’s where somewhere in true CPA out to MAG can get a mini jack from the increased forcing, orographic enhancement, and high ratio fluff that accumulates efficiently. I like your area for 10-15” with upside to 18” where you sit. Should be a fun storm! As for thunder snow, I like EPA and Central NJ as the best chance for that. It’s all but a given someone will have some and it’s likely within the heart of the CCB. .

No doubt MAG. I’ve been watching the track of the 7H and 85H lows very closely for the last few days I’m noticing a positive trend in that regard for a more widespread precip field, which is something I was entertaining the idea of early yesterday. The dynamics and overall low to mid-level moisture transport are classic for extensive precip on the NW side of the low, as well as further due north due to the intense 7H frontogen as the 700mb low strengthens, in tandem with the surface low due to increased jet coupling off the the coast. A track of the low between Wallops Island to Cape May latitude would place the eastern LLJ right through southern PA, eventually up to I-80 corridor through the eastern half of the state. It’s a great setup for significant snowfall and MECS probabilities increase for those that are fortunate to get into the CCB as it matures and pivots once the storm occludes. .

Well well well, I guess my Rt 30 to the Turnpike from Gettysburg, up to Harrisburg, over to Philly with a southern line down to 15 miles south of the PA line is in good shape as the best potential within both this sub and the MA sub. Looking good guys. I’m liking Lancaster County with this one, as well as York and Berks. I think the best will be just to the East towards Chester and MoCo PA counties, but 10-15” with Max to 20” is within the realm for someone in the forum. I’m heading to bed over yonder. I’ll have more tomorrow. Have a great night. Cheers! .

All is right in the world today. Great to see you back back @Bob Chill. I learned a lot over the years from you reading the forum and taking in information. Especially long range characteristics. Thanks for being a great person and glad you're doing well back east. Cheers!

Yeah. Mine was me cleaning and trying to get up from a tight spot as a big dude. I severely strained my right lat muscle, translating to acute ridiculopathy throughout my lower lumbar. That was 3 weeks ago and through a ton of treatment and muscle relaxers, it's improved where I can do most of my normal routine, just slowly. Still have some translated pain in the sciatic nerve, but it's tolerable compared to the past few weeks. That was debilitating. I hope you're having a decent day today!

Still resting my back from the injury, so I'm currently buzzing off a 350mg Soma and a tall bottle of water Hence the reason I have not posted about the GFS because I am toast lol

I'll tell you what, the RGEM has been eerily consistent on the evolution so far and placement of the deformation axis. I'm intrigued

As a meteorologist, one of the best things I do with the ICON is I don't look at it and wait for the GFS...... Seriously, it is never used in a NWS setting from anyone I know. Aesthetics only, but it's not a great model and it has been all over the place.

You don't want to mess with a man after he's had his coke

I'm more of a coca cola guy, but everyone is different

I think one of the reasons is the expectation is for the snow on the front end to only reach advisory criteria and they are leaning towards the coastal portion being further east, so it leaves the northern and western areas away from I-83 to be left out. That could be the reason. I'm a little surprised at the decision, but I'm also not at the desk at Sterling, so there might be more on the collaboration end with other offices (State College).

@psuhoffman already touched on the 500mb aspect of the Euro and how it was closer to something big, but just a bit off on the transfer details. Another thing to watch is the evolution of the 700mb low with regards to the transfer. I was checking the model comparison on Pivotal and I noticed the time frame of most interest will be hrs 72/78 for this section of runs. The biggest differences I find is the NAM and Euro hold back the 700mb low over the OH Valley while the remainder of guidance actually is in the process of a full transfer and enhancement along the coast. You can really see the difference at hr 72 GFS ECMWF NAM RGEM This is important because this is part of the delay in redevelopment of the NW precip field as the low becomes captured and pulled to the west. It will be very important to watch how the 7H and 5H lows evolve in the transition from the primary to the coastal and that happens on Monday morning. That is the make or break time period. If the transfer is clean during that time, the 7H low will strengthen off OCMD. If it's slightly late, it'll be elongated and have the greatest enhancement to the north, placing the best deformation axis over NJ. The Euro took a positive step forward, but it wasn't completely there. Regardless, even without the major hit, it still dropped a WSW criteria event across much of the sub-forum. Hopefully the positive trends continue and that piece in New England can scoot out or become weaker to allow for development and a cleaner transfer period.

Oh absolutely. This is a given with history on the side to back it up. There was a convergent area to the NW during the 2016 storm that slammed parts of PA while the deformation axis raked the 81 corridor. I think it's a 700-500mb frontogen that causes it, and that is some high ratio fluff too. Not as dramatic in total rates compared to the 700mb frontogen/deformation axis, but it will pile up quickly. That will not be situated until the 11th hour.

The evolution was perfect for I-95. It's likely underdone too in the intensity department given the dynamics and strength of the 85H and 7H lows. The placement was great though. A good sign

One of the things I'm noticing with the GFSv16 is a shift in the max precip field over the last several runs. It has built up the precip field and expanded the area of 1+" QPF, as well as ramping up within where it places the CCB. It has shifted from the Hudson Valley to central PA in the last 3 runs. Perhaps it's starting to catch on to an earlier capture and better mid-level frontogenic placement to the south? Maybe it's still trying to decipher the surface low placement given the nature of the transfer? Maybe it's Maybillene?

I was looking at the UL evolution and I really don't understand why it did what it did. It wasn't THAT far off from the GFS, but it was way off with the CCB comparatively. GFS has a slightly better 7H presentation, but it wasn't super different. Not sure. Wasn't a terrible run, but I think it could've looked a little better at the surface.

I don't care if I have kids, dogs, or aliens... I have not and will not give up bagel bites. A true guilty pleasure lol

I hope no one asks the storm where it wants to eat for dinner....