Newman

Ukmet is a huge hit!

DGZ is -12C to -17C. For many across SE PA, the entire atmospheric column is between this up to like 600 or 500mb. Even down to the surface in many places. If you throw some strong omega into the mix, poor snow growth would be the least of my worries. You're right though, if things were colder than -17C then we'd be looking at less stellar dendrites

6z GFS Op and GEFS came north again, AIGFS is a southern outlier for now. With a potential phase that models seem to be heading towards, I think a southern slider solution becomes much less likely

Are you thinking about chasing this one or gonna stick it out in Philly? I guess it depends on where we end up with this in a few days...

Yep, the 6z Euro AIFS also came back north and heading in that direction. We'll see if it's real at 12z

I'm pretty sure the Euro is going for an overrunning to coastal scenario. Looks like a completely different look now with a closed trough over the central Plains. Full phase

Absolutely, this will be a frigid storm. Just wait until we get into range for our CAMs that can handle banding.

Ukie another big hit. A bit less amped from the insane 12z run, but still gets 1" QPF to Berks and Lehigh.

Although I wouldn't go too crazy with ratios, seeing super deep DGZs like this could easily net you a 15:1 average ratio through the storm. Some places would exceed 20:1 within banding.

1" QPF line right along I-95 south on the CMC 0.8-0.9" throughout SE PA. 9° in ABE at the peak of the storm, 13° verbatim in Philly.

There's the north jump on the GFS and the CMC about to lay down the hammer.

Oof, +60Bz is absolutely insane and cruel. Probably one of the strongest CME impacts in decades and the Bz is positive instead of negative. Would've been a modern day Carrington if that came in negative

So obviously I don't live in SE PA anymore, I've got a comfortable met job in Florida. But these MECS/HECS are just so fun to track and a great way to keep my meteorology skills sharp. My met job down here in Florida is so focused on tropical weather, except this past weekend with the snow haha. Man I was getting so bored of sea breeze convection all summer. When I lived in Berks throughout the 2010s and early 2020s, I think I forgot how rare storms north of 15-18" really are. For Philly, anything above 17" gets you into the top 10 of all time. And it has only snowed 2 feet there twice in recorded history. For ABE, a 20" storm puts you into the top 7 of all time. Of course, the past few years have been rough for big ones and I think it should make this even sweeter (if it does happen, no guarantees yet). We got so used to these MECS during past decades that, personally, I lost sight of how rare and treasured they really are. Remember, places like KPHL go back to the late 1800s and early 1900s sometimes with record keeping. So when you see these model outputs throwing around 1-1.5" of QPF into a cold dome with surface temps in the lower teens, you're immediately talking about something that has only happened maybe a handful of times in like 100 years. That in and of itself makes me appreciate just tracking the opportunity for something like that.

This was a great shift north on the NAEFS from 0z to 12z. I've found that the NAEFS are just as useful as some of our other ensembles because they take the CMC and GFS guidance combined. It's sorta like a North American specific grand ensemble. Just SE of I-95/Philly jumped from 0.25 to 0.5" of QPF. 0.25" extends well up towards I-80 now. Obviously jumping ahead a bit here, but for those who end up on the northern side of the precip shield and aren't smoking cirrus, you'll usually have a solid 700mb fronto band set up and can eek out additional inches that way.

If we take into account *probable* ratios, the Euro now has 6-8" extending up to Berks and Lehigh. And I don't think this is done shifting north. Even as is, I think most south of I-78 would take and roll the dice for a different jack with the next storm systems

Ukie is a great hit

Absolutely, the 28-29th seems like a great coastal storm threat as well. There will be plenty of chances

If the CMC is even close to right and we get that energy to eject and phase, then holy shit

Best case scenario is something like what we saw with the fantasy GFS run a few days ago: the Baja California energy ejects very efficiently and runs into a brutally deep cold dome and we squeeze out a lot of moisture along the baroclinic zone. The worst case scenario (and the most likely fail mode) is the energy gets held back and or doesn't eject efficiently and it's a congrats Richmond. And also if the HP keeps trending stronger. But until then, I see absolutely no reason to worry about rain in this set up. If the 6z AI GFS happened, then sure you might flip to sleet. We will have to see wholesale changes with the Arctic high to worry about rain

Details to be sorted out later, the good news is it's looking highly likely that someone along the East Coast will get a storm this coming weekend. Models will waffle north and south all week. But tbh, I'm feeling really confident for areas I-80 south. These things almost always come north. As long as we don't see models trend towards holding back that energy in the SW, I think DC -> NYC is looking good

6z AIFS would be a certified banger for Philly. Surface temps hover around 10-14° as you squeeze 1-1.5" of QPF into this cold dome.

1.5" from round 2 in Fleetwood 3.625" on the day 8.2" for the weekend 16.625" on the year, which is ~2 weeks ahead of normal (first week of Feb)

Considering how well the AI models did with the weekend storm systems and in general (their verification scores are much better than their physics based versions), it makes sense to rely on them for the upcoming period. At the synoptic level, it's the best we have. All of that to say, the 18z AIGFS looks great for next weekend. The Euro AIFS was even better at 12z. Long ways to go

That 850mb fronto band really bringing the goods further NW into Berks/Lehigh. Folks already got another inch this round

An additional 2" in Fleetwood this morning. I'm not expecting much more west of 202 the rest of the day