Newman

This is the warmest the 12z HRRR gets at KABE. If this is the case, you'll probably mix with sleet, not do a full change over. Under heavy rates you might flip back and forth between all snow, and a snow/sleet mix. So ratios will be more like 6:1 or 7:1 vs a pure sleet 3:1.

3.75" already in Fleetwood (per family). Rates have been ~1.25 in/hr or so

700mb fronto starting to really show itself with heavy radar echoes blossoming across northern MD and South Central PA, heading east. Heaviest snows of the days are about to begin for many in SE PA

Probably briefly stuck between heavier bands so poor snow growth with rimed flakes. It most certainly is not sleet.

11z mesoanalysis has the 700 0°C line down in southern VA right now. Problem is the warm nose looks like it's between 850 and 700mb and we don't have a map for those layers. Regardless, just based on early reports, I like the NWS nudging amounts up slightly for the LHV. I think ratios and rates will get y'all to your expected ranges and potentially above in some spots.

I would probably drop my totals for Berks from 10-14" to 8-12". At this point, it kinda is what it is. A flip to sleet is looking inevitable up to at least the I-78 corridor. I would not rule out 14" for Berks though if something like the HRDPS or FV3 come to fruition. I would also not rule out 6" if one of the aggressively warmer models works out. A blend puts you at 8-12. We're at the stage where much of the public has already made up their ideas of this storm based on forecasts they saw 1-2 days ago. We'll know what the final verdict is by tomorrow night. Basically, it's down to nowcasting.

Deep down I'm hoping y'all pull a November 2018 and the warm nose ends up less pronounced and things stay snow longer.

Long range HRRR finally getting a clue and sending the sleet line up to I-78, but quickly washes it out and sends it back south.

We just have to see how hot and heavy that initial thump comes in, especially for NW of 95. HRDPS is advertising 8-10"+ in 6 hours tomorrow morning. Just based on experience, I'd imagine some places could even grab 12" in that time

The NAM continues to be the most aggressive model with the warm nose punch. Not to mention it always has runs like this where it flip flops around. I'd give the NAM a few more runs until it gets within 48 hours to take it more seriously.

Yikes, 18z NAM is a disaster.

Hey Paul, I don't have that list for you readily available, sorry! The NOAA climate sites that I use for this allow you to parse the data by day, but not necessarily by "storm". So I could find this for you through some manual interpretation and adding up snow from known storms by each day, but I can't do it right now haha.

Here are the top 15 snowiest days (i.e. 1-day period) in recorded history at KABE dating back to 1944. This storm could very easily break into the top 15, or even top 10. Most if not all snow falls between 2am to 10pm Sunday.

Looks like Mount Holly included Berks for the 10-15" warning in the area between I-78 and I-95. And then areas along/near I-95 and south it's 8-12". North of I-78 it's 12-18".

I still like my Adams -> Dauphin -> Schuylkill -> Carbon -> Monroe call as to where the southern edge of the jackpot zone might set up. You want to be on the north side of the 850mb fronto and unfortunately I could see poor snow growth/crystal habit in the sinking air south of that fronto band. However, it is encouraging seeing things start to tick south and colder

Lol, the FV3 is super cold. That is its typical bias though so I wouldn't put much stock in it. It's got the sleet line still south of Philly by 0z Monday. Significant snows north of that across all of SE PA verbatim

By 1pm Sunday it also has significantly more snow across the area. It doesn't look like a timing difference to me, just more QPF and better ratios/rates.

Wow the 12z NAM just made a jump towards the GFS evolution, keeping things a bit more strung out and transferring to the coast sooner. Still gets the sleet line up to Central Berks county, but no further north. And then things crash back south with more to come early Sunday night. This is probably the NAM doing NAM things, but fun to see and if we see models tick that way at 12z, I might give it credence. Will need quite a few more ticks to see a lot of snow on the backside, the dry slot still kills anything past 03z

6z GFS is big time for Feb 1

If the GFS is right, we will easily see this storm rank way up there on the NESIS scale. Below is Jan 1964 which is 8th on the list. And this storm could have an even more widespread 10"+ swath. Just something fun to think about. What really makes or breaks how high up these storms get on the NESIS list is how much snow DC, Philly, NYC, and Boston proper get. Because the NESIS equation specifically takes into account population AND how much snow said populations get

The 18z Euro AIFS did make a small nod to the GFS in that it kills off the primary and transfers to the coast sooner

GFS looks nice but I'm not believing it. It's what you'd expect it to show at this stage with its typical progressive bias. With the snow last Sunday here in Florida, it trended significantly more amped just within 24 hours of the event.

Like Mike said above, looks like IP to me!

I would personally go 10-14" right now for Berks, briefly ending as sleet for up to 1-2 hours at most. I think the highest amounts end up along an arc through Adams -> Dauphin -> Schuylkill -> Carbon -> Monroe counties... so just north of Berks and Lehigh counties. I am personally expecting a slightly more north warm nose than what the NWS is currently forecasting, but if I am wrong and it stays all snow then 12-16" (as it says in their WSW) is right on the money. I think the ceiling is around 18" under a perfect scenario, the floor is around 8" if things really start to shift north. I haven't seen any guidance spit out more than 1.1-1.2" of QPF. A storm average 15:1 ratio with 1.2" QPF gets you 18" if it's all snow.