Ralph Wiggum

Not sure I trust the GFS for qpf depiction. Always seems tight with gradients and less expansive than say the Euro or the mesos in that regard. Tends to run drier overall as well.

GFS is another dumping for us. No red flags, steady as she goes. Eta: Light snow thru Thursday evening wow. 24 hrs+

Better track for DC and BWI this run. I wouldn't put much stock into banding or lack thereof on the gfs global. Wait for mesos to get in range. Great trend for my Southern friends imo.

HP doing its dirty work. Filthy!

GFS is going to make friends tonight.

My wife said that to me once.....and now 2 kids later.

A few steps below the major models (GFS, EURO, CMC) but one step above the jv models (NAVGEM, JMA). Probably could be compared to the ukie. It is notorious for screwing up thermals and doesn't show mixing....either snow or rain. Use it for general guidance and to see which other models it trends towards and that can provide some useful clues for forecasting.

RGEM is insane for SE PA. Epic banding. 24" lolli a few miles from me. Saving this map for archival purposes. Doubt that even comes close.

ICON is an improvement. Stronger better positioned hp/CAD...thus colder. Starting to come around to other guidance finally.

I wouldn't rule out the mix line getting to my area in Central Bucks but there will be enough moisture to provide snow depth prior to AND after the mix line punches thru then falls back. And that's still an IF the line gets this far N and W.

Every other model is at least 10" here conservatively and the NAM is widespread 1-4" PHL, Delco, Chester, Montco, and Bucks? Ok.

The NAM either needs to be retired or is dire need of an upgrade. When was the last major upgrade aside from adding the 3k resolution? At range the 12k is horrid.

That silly model is hell bent on giving us a major sleet event. All by itself it appears. Im fairly certain we can chalk it up to the NAM doing typical NAM stuff at range. If you follow the 500mb vorticity maps and compare with 18z there are improvements until about hour 54 irt slightly better confluence, slower departing hp, and better organization/tilt to the bowling ball coming across the Plains. Then at 54 hrs the surface gets all wonky. By this time tomorrow we should have a classic NAMming under our belts....I thought we were headed there just now until it got whack with the slp placement running into a deeper and better positioned hp.

It sure does!! Still has that damn subsidence thing right over my area in Central Bucks. Different than the dry slot we saw progged earlier. This looks like a subsidence zone behind the area of insane frontogenic lifting. Going to be tough to nail that area down. I mean would it matter that much though we are talking the difference between 20" and 13" lol. At this point after the past few years I'm quite happy with a Warning criteria system.

GEFS are moist.

New thread started. I'll take the heat if its jinxed.

Put all discussion here for the upcoming December 16-17 winter storm. Let's keep it on point and clean.

Again, not saying we will continue to see the slp tick farther N before moving East BUT you need only look at the most recent example on our doorstep for tomorrow. That system was progged well to the South just 36 hours or so ago then began ticking N and amping more each run. Now this should help the system for Wednesday, but it needs to be watched as this is the 3rd system this month already to come farther N. Not my final call at all, just saying it shouldn't come as a shock to anyone if we continue seeing the trend. The saving grace for Wednesday is CAD....confluence, a 50/50, and some blocking up top.

Bingo

Dry slot as system briefly closes off and starts occluding. Not sure if that trend is correct or not yet. At work not much time to digest everything.

Yep, surprised nobody mentioned the closing off at h5 and the comma head opening up pushing the dry slot up into SE PA.

12z suite takeaway i95 and 10 miles n and w are losing wiggle room.

Not my forum, you guys can start it whenever. I know Im not doing it....im superstitious and don't want the blame when the NAM scores a win lol.

Lol, you guys even mention snowblower tuneup then the NAM comes in with the farthest N and W track of any model. Admittedly I dont put any stock in a 78hr NAM map but I just thought that was funny. Eta: Verbatim the NAM is an epic sleet storm for most of SE PA

Has 13" for you and I. We gladly take. Eta: The 'odd' look is because there is a transfer happening at the exact 96hr panel so it appears as 3 or 4 meso lows.