ORH_wxman

Well not all systems are gonna have the marginal thermal profiles that we see tomorrow...no guarantees, but the larger scale layout for next week looks a lot colder. We have climo working in our favor too as we go deeper into December. Originally, we weren't expecting anything for 12/2 (we kept saying it looks better after about 12/3ish), but then this system kind of snuck into a colder airmass about a week ago on guidance...so we were hoping to score a bonus event early.

GFS looking better for the 12/10-12/12 period...there's a couple of shortwaves in there....and those won't be figured out until later, but good things happen when we amplify that western ridge a bit like on the 18z run.

Hoping model guidance underestimates the density of this cold dome over us tonight...could a make a difference when we're talking like 1C in the BL. Guess we'll see on the 00z and 06z runs.

EPS is def more aggressive than other guidance trying to get a few inches in here on Saturday. A potential bigger threat would be middle of next week around the 10th-11th....but that one is all over the place. Lets see if we can amplify that ridge a little more out west....because we have a nice -NAO and some low heights in SE Canada which bodes well for actually trying to hold a high in place.

NAM coming in a little flatter so far than 12z

It’s def had a cold bias in the medium range the last few years. It especially does when we’re talking these SWFE or WAA type storms. The old euro actually had a slight warm bias in the medium range but it was still the best model by a lot.

One more tick warmer and the evening commute will be fine too across even interior SNE north of pike.

Yeah that’s further SE than pivotal by a decent amount. Sv is awful.

Euro a slight tick warmer than 06z...matches GFS basically.

He's prob toast too if I'm toast. We need a little trend back between now and tomorrow but that becomes less and less likely as you get closer to verification. Models are more likely to be correct when they shift the closer we are to an event.

Yeah rates def not quite as good as 06z. I think I'm pretty much toast here. Winter hill might do really well still as long as we don't get a zonked NAM look.

Was gonna say i was surpsied to see GFS might actually look a tick flatter through 18h

Messenger shuffle would happen between now and go time...usually inside 24h. The lack of the high pressure even sort-of holding on probably will sink us again....it's been a killer for like 4 winters now. Cannot buy a high to even try and hold on.

ICON warmed a good bit too...not as crazy as NAM, but a solid tick. 12z runs are definitely seeing something so far. RGEM looked a little warmer too, but a very small amount vs 06z.

Unless this ends up as a total model failure inside of 30 hours, you're pretty much a lock for 8"+

Looks like those NAM runs from like 4 or 5 cycles ago. Not the ones that brought mixing to dendrite ,but maybe those runs just after that where it was still bring it to the NH border pretty easily.

Fundamentally handling the vort differently this run....keeping it strong into N Ohio....it's gonna be a warm/zonked run.

NAM is gonna be more amped than 06z just based on 12 hour panel.

Lol, basically has no snow in SNE outside of far N ORH county and N Berkshires. Completely different evolution though...doesn't close off 850 until way later than other guidance.

The only time I would bring in sun angle in December is if we have like a light glazing situation with temps near freezing....that actually happened in the Dec 2008 ice storm....we were having trouble accreting during the day on 12/11 with temps of like 31F, but it went to town when the sun set. Maybe it would also make a difference if you were having like a steady light snow near 32F. So maybe in the first few hours of this storm it could have a marginal impact, but it's not doing anything once you get to moderate rates.

Def still a signal there on EPS

December sun angle will get you every time.

06z GFS had it pinned in roughly the same spot too. But this is a situation where like 10 miles could be the difference between 10" of cement and 2" of slop.

The really high resolution stuff (HRDPS/3k NAM/etc) overnight keeps the CF pretty far east. like near 128 or even slightly east (further north you go the further east it gets)....that's something to watch because it's likely going to stay snow on the cold side of that....usually there is some enhanced lower level lift on the left side of that CF which will help to cool that lower 900-950mb layer a little bit...which will obviously matter if we have temps near 0C in that layer.