CAPE

@WxUSAF

It might be interesting/useful for you to create an h5 anomaly plot for each of those Decembers individually.

It's definitely possible for a little something. I would think the further west the better, with it tending to dry up as it moves east.

Still looks like a tough one with that ridge progressing east and that vort lobe tracking right overtop.

That is a multiple year monthly composite mean at h5 for December. There would have to be some amount of ridging in the Western US (during Dec) for at least parts of some of those years. When presented as a multi-year composite, the height anomalies there are less prominent and get 'washed out'.

So far only some small branches down here and there. No leaves on the trees helps significantly

Yeah the wind is fierce here now. Helping to sublimate my little coating of snow.

That is the typical -NAO dipole look. When there are anomalous +heights over the NA, the heights adjacent to it are anomalously low. The oddity is the ridging that has been occurring underneath lately despite that. It is what you would generally expect if the NAO were significantly positive(lower h5 heights over GL). eta: a super -PNA can certainly overwhelm a weaker/east based -NAO, but typically if the NAO is legit negative, SE ridge is suppressed.

The low visibility for a time was pretty impressive. The pond is covered to keep it from filling with leaves lol.

31 and still coming down but brightening up. First flakes, flizzard, and coating.

Way more impressive than I thought it would be. Too bad the ground is sopping wet and the temps didn't crash quicker.

Pretty legit flizzard here now. Sideways snow. Actually starting to stick a bit.

Same here. Temp down to 36. Moderate now with pretty big flakes. Zero stickage ofc.

Sudden burst of wind and all snow coming down now.

It's heading in the same direction.

Temp down to 40 with some wet flakes mixed in. Had one burst of wind but its backed off for now.

GFS against the world failed again.

46 and pouring here now. Not much wind yet.

Canaan https://www.canaanresort.com/resort/webcams/

Maybe go back and read Psu's post again.

Replenishing the cold into our source region can happen pretty quickly once the TPV over AK retrogrades towards the Aleutians, in combination with ridge development in the PNA/EPO domains.

Marked improvement in the advertised h5 pattern towards the end of the 0z GEFS, especially out west. Hopefully the reshuffle/mild period lasts only about a week.

I have always found the TNH impacts on our weather to be a bit nebulous. Anecdotally if either phase is strong it can have negative impacts wrt the desired outcome of cold/snow in our region, and it seems be more problematic in combination with a Nina.

Snippets from Mount Holly AFD this AM- A strong line of showers is expected to accompany right along or just ahead of the front as it passes through. Also, there will be another surge of southerly winds in tandem with a 50-70 knot low level jet ahead of the front. All of this will be in response to the incredible amount of forcing and energy this system will have. Expect the front to move through the area quickly with it likely arriving in our western zones by around 8-9am, the I-95 metro around 10-11am, and then clearing the coast in the early afternoon. Expect there will be widespread winds gusting 40-50 mph through the day Friday, first out of the south ahead of the front and then sharply turning westerly behind it. The aforementioned line of showers along the front may be able to tap into the accelerated winds not far off the surface and mix down some higher gusts in the 50-60 mph range increasing the threat for wind damage and power outages. Right on the backside of the front, hi-res guidance and model soundings are favoring a transition from rain to a quick burst of snow as the temperatures plummet below freezing. The other concern we ave associated with the rapid introduction of a very cold airmass is the potential for a quick freezing of wet surfaces causing widespread icy conditions. One factor we may have in our favor to combat a significant flash freeze is the few hours of precip-free conditions leading up to the frontal passage, thus surfaces may not have a lot of antecedent moisture. It is also possible that there may be a brief time lag between the frontal passage/rain and when temperatures plunge below freezing; a short timespan between those two occurrences coupled with elevated winds may allow some surfaces to dry and limit freezing potential. But with all that said, the potential for dangerous, icy conditions and slick surfaces is certainly there and we will continue to closely monitor through the morning. By late day, as temperatures continue to plunge, dangerously cold conditions will become the primary hazard. So all in all, still expecting a wild day weather-wise. It`s worth noting that the combined impacts of any power outages due to the strong winds plus the extreme cold to follow could be significant.

Temp of 46 at 5am. Wind ramping up some. 0.62" of rain so far. Not much at all overnight. Quite a bit less than forecast.