Newman

The differences between the CMC and GFS are huge even 5 days out. There is no confluence whatsoever on the CMC

-2 in Altoona and a balmy 58 in Philadelphia

Raleigh NC the place to be on that GFS run, back to back jackpots less than 3 days apart

Is it wave spacing, the fast flow, unlikely "perfect" phase, geographic location, or something else that would make you say the ceiling is a SECS?

From Mount Holly This changes as we go to the end of the week. While there are timing and placement differences with the long term guidance, all of the long term models are indicating the potential for a coastal storm to affect the east coast Thursday into Friday. Each have a coastal storm developing to our south, before a disturbance moves in from the west, bringing colder air with it to the area, and strengthening the low as it approaches. This is a week away, so there is plenty of uncertainty, so for now we will stay close to the NBM for the forecast.

I've always been a HECS or bust type of person when the ingredients are all on the table. A sneaky 2-4" event two days before? Definitely welcomed. A big dog being progged days to weeks out? Yep, give me the big thing. I will of course take anything for a White Christmas, but I will be chasing this thing for big one potential

Agree, the timing was off and we still got widespread 6+". The ceiling is without a doubt 12"+ widespread, but guidance showing warning level snows even with the pieces sloppy is encouraging

Happy Hour GFS with a nuke!

Snowing again, mid-level warm layer is crashing and can see mix line moving back south on correlation coefficient.

Euro is soooo close. Verbatim still gives the entire area light snows, but we're talking miles and it could've been another bomb. This 500 look is out of the NESIS textbook

Current mean on the GEFS for the 23rd system is very impressive being 8 days out. Some huge hits, and the miss right now would be a SE scraper, not NW and a cutter.

There are some huge indi GEFS members this run. Some faster on the 23rd, some slower on the 24th. Multiple hits, and the lean right now would be a SE scraper, not NW and a cutter. The mean 8 days out is an advisory, borderline warning level, snowstorm

Christmas Day wind chills

Closed low opens up and just squeaks by to our SE that it's mainly a coastal bomb. It was so close to being a widespread MECS

GFS with a bomb incoming

Sleet mixing back in, temp has dropped to 30 with the onset of precip. Can see mix line on correlation coefficient radar very well

HUGE snowflakes coming down now, mostly snow. Some flakes the size of my palm, no joke. Like almost 2" in diameter

Just sleet here in Fleetwood, coming down nicely though and streets covered. 32F

The CMC was a hair away from a bomb as well, verbatim destroys New England. It's an explosive setup with that northern stream shortwave and favorable confluence/blocking.

I think it's obvious that the snow maps just aren't gonna work in a system like this, there's gonna be lots of ptype changes as rates change and such. The GFS being colder is inherently apart of it's bias to be progressive and less amped... it's just not showing as much mid-level warming as say the NAM and RGEM (which have a bias to be too amped). I honestly don't know what to expect here in Berks. I'm at a higher elevation compared to the southern part of the county which will help.

0z GFS came in even colder again. Even if we compare the snow depth maps, there's a clear shift southward.

18z HRRR. Don't take the 10:1 snow map literally, instead see it as where the line for where predominately frozen precip will fall vs not. The HRRR is MUCH more generous and cooler aloft compared to the NAM. The NAM drives a warm nose aloft into the region while the HRRR is very stubborn to keep it tamed