DECEMBER 16th 17th 2020 Snow Threat???

With the caveat of sroc in mind that we shouldn't ride the models run to run . . .
The 18z NAM is a definite significant shift at the surface level. It is bringing the heavier snow totals much further south and east than in the 6z and 12 z runs with less mixing/and virtually no dry slot on this run. Snow totals in excess of one foot almost down to I-195.

The 18z NAM looks completely different from 12z NAM. It now shows a Godzilla for many, eliminating the extreme NW low solution and adjusting SE in response to the confluence/High Pressure to the north. I think it needs one more run to figure out the precip, but at least it's looking in line now with other models in terms of track.

It is only one run, but the NAM just took a major jump to be more in line with the GFS and Euro.

@billg315 wrote:It is only one run, but the NAM just took a major jump to be more in line with the GFS and Euro.

Yes, but its depiction of the precip is not right. I think we need to give the NAM one more run to adjust. It took huge leaps though in terms of where the H7 and H85 lows track.

@Frank_Wx wrote:

@billg315 wrote:It is only one run, but the NAM just took a major jump to be more in line with the GFS and Euro.

Yes, but its depiction of the precip is not right. I think we need to give the NAM one more run to adjust. It took huge leaps though in terms of where the H7 and H85 lows track.

Better one

@Frank_Wx wrote:

@Frank_Wx wrote:

@billg315 wrote:It is only one run, but the NAM just took a major jump to be more in line with the GFS and Euro.

Yes, but its depiction of the precip is not right. I think we need to give the NAM one more run to adjust. It took huge leaps though in terms of where the H7 and H85 lows track.

Better one

Why such a different on the southern PA etc on wxbell than the TT, they both the same snow map but the wxbell leaves almost no snow to the eara TT gives godzilla snows to. I think maybe wxbell map is wonky?

@Frank_Wx wrote:

@Frank_Wx wrote:

@billg315 wrote:It is only one run, but the NAM just took a major jump to be more in line with the GFS and Euro.

Yes, but its depiction of the precip is not right. I think we need to give the NAM one more run to adjust. It took huge leaps though in terms of where the H7 and H85 lows track.

Better one

Yeah this is more in line with the 18z NAM snow map I was just looking at.

@Frank_Wx wrote:

@Frank_Wx wrote:

@billg315 wrote:It is only one run, but the NAM just took a major jump to be more in line with the GFS and Euro.

Yes, but its depiction of the precip is not right. I think we need to give the NAM one more run to adjust. It took huge leaps though in terms of where the H7 and H85 lows track.

Better one

The Tidbits map includes skeet, Frank, and there’s a warm layer that gets to I-80 on the 18z and flips to sleet until the 700 and 850 lows pass through with the dry slot. Then it fades.

While I totally agree with sroc not to hug the models run to run, and Frank is right that we need another run from the NAM to really start to get it "right", the fact that the NAM was really the only outlier with that horrendous solution this morning and now is coming more in line with the GFS/Euro, is certainly a positive trend, and a hint that it really was off base with its initial outputs earlier today.

Winter storm watch just posted for my neck of the woods!

rb, on the site I was viewing the 18z NAM on I didn't really see much dry slot at all (compared to earlier runs), and the mixed precip was limited to the southern tier of PA into central NJ near Mercer County and south. Or am I looking at it wrong (which is always possible. lol).

@rb924119 wrote:

@Frank_Wx wrote:

@Frank_Wx wrote:

@billg315 wrote:It is only one run, but the NAM just took a major jump to be more in line with the GFS and Euro.

Yes, but its depiction of the precip is not right. I think we need to give the NAM one more run to adjust. It took huge leaps though in terms of where the H7 and H85 lows track.

Better one

The Tidbits map includes skeet, Frank, and there’s a warm layer that gets to I-80 on the 18z and flips to sleet until the 700 and 850 lows pass through with the dry slot. Then it fades.

Yes. The main point I wanted to get across is the mid level lows have trended south in consecutive runs on the NAM. Again, with 48 hours to go we can easily see the NNW solutions come back on the models. I don’t doubt it, for all the reason you have laid out, but it’s hard to doubt that block to the north right now. Cold air is literally seeping further south and east on every new model run. The dynamics alone will get some places to 10” of snow in just 6-8 hours.

LMAO literall all around upton has WSW, but i guess they decided its go miss us lol, im kidding they always the last ones.

There is no way in hell that the one foot line will be near Albany into the Vermont New Hampshire border not with dew points around 0. To + 5. There's going to be a sharp cut off on the Northern Fringe maybe 50 to 60 miles wide you go from one foot to 2 in

Jman, to your question about the maps around the SE PA/Philly area, this run of the NAM has a significant period of sleet and freezing rain in the Philly metro area. That would keep their snow totals down, although some spots there showed almost up to .5" of frz.

@billg315 wrote:Jman, to your question about the maps around the SE PA/Philly area, this run of the NAM has a significant period of sleet and freezing rain in the Philly metro area. That would keep their snow totals down, although some spots there showed almost up to .5" of frz.

yikes thats a really bad situation if a ice storm unfolds down there, I like where I sit, my area has not been out of 12+ on any of the model runs. Maybe the least 10+.

18Z NAM

I'd love it but there's no way this is anywhere close. Toss for now.

The cruelty of it all.

Omg just as I sent that last post, WINTER STORM WATCH is officially hoisted by Upton!

Issued By
New York City - NY, US, National Weather Service
Affected Area
New York City, and western and central Long Island
Description
...WINTER STORM WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON...

WHAT...Heavy snow possible. Some sleet could mix in late Wednesday night. Total snow accumulations of 8 to 14 inches possible. Winds could gust as high as 50 mph.

WHERE...New York City, and western and central Long Island.

WHEN...From Wednesday afternoon through Thursday afternoon.

IMPACTS...Travel could be very difficult to impossible. Hazardous conditions could impact the Wednesday evening and Thursday morning commute. Gusty winds could bring down tree branches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

@SoulSingMG wrote:The cruelty of it all.

LOl I just posted this, and you just then said it was hoisted so ill go look.