Jump to content
  • Member Statistics

    17,601
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Central PA - Winter 2020/2021 Part 2


MAG5035
 Share

Recommended Posts

1 hour ago, MAG5035 said:

A big key to what we're going to see snow wise with this system is what happens right up front late tonight into early tomorrow with that finger of early warm advection snows that develops and where it's placed as that probably will be the best snows ratio wise and could throw a stripe of a few inches right off the bat to whoever gets it.That's really been the name of the game with this system since last week, what it does on the front end... even with it being a much colder system overall than it was looking at that point. 

At any rate, it seemed like a good bit of guidance today (especially the short term and high res stuff) places this early stuff closer to a JST-UNV-IPT line than say a Cumberland to MDT one and then the main surge of precip fills in the rest where it will probably be heavier overall in the southern tier. This is actually most important for that corridor (JST/UNV/IPT/FIG) because this may be a low end advisory or worse without it in the central counties.  I'd wager the folks that gets a good piece of the early stuff and transitions into the main surge without wasting a period of light or non-consequential rates are probably going to be the ones that see the best accumulations for the whole event. And if that actually does end up back as far as that JST-IPT corridor, I'd def be more worried about the implications of eventual mixing in the LSV counties. NAM and related near term guidance is the mixiest still, while generally everything else minimizes the mixing above the mason-dixon line. Still have the same concerns with the 500mb mean trough centered west over the central US as well as the mid-level features west of PA and associated WAA busting 0ºC somewhere in that 850-700 layer in esp the LSV. 

The trend the last couple days has been a bit of a SE shift in the heavy swath and especially an overall toning down on QPF. I think this is basically a 4-8" for all the regulars in here. Clearfield and Williamsport should eventually at least get to 3-4" by the end of this event. Places like AOO/UNV 5-6" and the best chance of a consistent 6"+ swath likely resides closer to the turnpike. Below the turnpike in the southern tier/LSV has the best QPF for widespread 6"+ but that directly depends on if the mixing happens. If it does, I still think everyone gets 3-4". The upper end of this is probably 10".

Great post!

I agree... 4 to 8 inches of snow tomorrow is a great call for most of us.

Link to comment
Share on other sites

Mount Holly's writeup also mentioned the sun angle, so it isn't just Glenn. Here's the website I use (both for meteo and other pursuits) plotting solar azimuth for basically any location on earth on any given day (but here linked to Philly): https://www.timeanddate.com/sun/usa/philadelphia. We're up to 38.7 degrees tomorrow at 12:14pm, vs Decem when our angle maxes in the upper 26 degree range. We're heading into the part of the year where the sun angle, day length delta (etc) are all rising rapidly day-to-day. I don't think it matters much for "the thump" but it matters later in the day--so it isn't just cya messaging. They're not wrong. Fun fact: 50 degrees of azimuth is about what you need for UV-B light to reach the surface, and thus, for your skin to produce vitamin D. 

That's a post from the Philly thread - the pros at Mt. Holly are discussing sun angle. 

  • Like 2
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...