MillvilleWx

The RGEM is just a more intense version of the Euro. Has a much more aggressive CCB over E PA with extension down to I-70 latitude. The fact that and the Euro are that consistent with each other might be hinting closer to an expected result. It’s still not a bad run with pretty much all the sub-forum in WSW criteria snowfall. Will be a wintry scene on Sunday and Monday. .

This is very true. I'd fly home for those suckers

I think @paweather @pasnownut @AllWeather would need a cigarette if the RGEM verified.

For the people 850mb Height 700mb Height

7H and 85H low development on the RGEM is total NSFW stuff. I might need @stormtracker permission to post something this naughty @psuhoffman Bro, you're gonna need a cigarette looking at the precip panels

That's exactly what I mentioned to @frd above. It was certainly better than the parent, but man oh man, that looked ugly. There wasn't even anything resembling a pure deformation axis anywhere except maybe coastal NJ. It was weak sauce. That would be brutal for NWS offices in the NE, especially Mount Holly and CTP

It would be a major coup, but I think the NAM may be having issues with the transfer idea. I will say, despite the NAM Nest looking better than the parent, it's still well short of every other guidance. Hopefully it's too rambunctious on the dry air intrusion within the mid-levels and it moistens up towards game time. It was paltry otherwise. Even the 85H wind field sucked for boundary layer moisture penetration further inland. Certainly on an island, but it can be a hint on things other guidance might miss. I'd hold off giving it too much weight beyond the WAA piece.

I'm heading to Twitter to DM him on what WPC preferred blend is so far for guidance because it looks like they are using ECMWF/EC Ens/GFS considering the surface forecast.

Not saying much. If the NAM is remotely right, it will be a pretty large fail with the rest of numerical guidance. Hopefully it's not on to something for everyone's sake. It's pretty crap until almost the PA turnpike

The NAM is in a whole other world in the upper levels and it's low placement is directly over the convection in the Atlantic. Not even the HRRR is that ridiculous. I mentioned this morning, it's either going to score a major coup and every other piece of guidance will be off the rails, or it's on an island won't come back until it's basically beginning the transfer. The WAA piece is at least still pretty solid.

65/10 with winds gusting to 40 mph

Couldn't agree more. This will be a rapidly developing cyclone with intense 7H dynamics as shown by models for several days now. You're going to have snowballs falling from the sky considering the massive lift across the region. CCB love is so hard to fully pin down, and the GFS/CMC also had a bit of a TROWAL signature on Monday night as the storm begins to occlude. I'd love to see the theta-E analysis and satellite when it gets to that time. Wish I was home for this one man. Cheers to large fatties falling while ripping a few fatties

The transfer was clean and very similar to the overnight runs of the Euro. One of the things that would make this better is if the 700mb low were to be about 25-50 miles further south. The deformation axis still gets down efficiently into the northern and northeast portion of the sub-forum with heavy snow for several hours north of I-70 and further NE. Even to the south, there would be high ratio fluff that would fall for hours, slowly accumulating with a final storm total of 8-12" from I-66 to Howard Co. Then 10-15" with local to 20" to the north. It was a great run for @mappy and @psuhoffman as it held serve from previous runs, and was in line with the GFS/CMC. One of the biggest differences from previous runs is it actually upped total precip within the deformation zone, so amounts are a touch higher north of I-70. It was closer to a bigger run for the whole sub-forum so chalk another up to a slight positive trend.

Something like 1-1.3" SW of DC with 1.5-2" between DC-Balt. Then north of I-70 like 1.8-2.3" up to the border. It was like a perfect positioning with GFS QPF. A beat down would occur over the northern tier

The UKIE is way too dry for that evolution. That would smack the forum pretty solidly. Hell, it's not bad as is.

Okay guys. Be honest.... How many have needed a private room the last hour of 12z runs?

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. .