USCAPEWEATHERAF

Yes early onset OES

I don't think Ray will be right about the Cape, perhaps the Islands, not the Cape.

Not with a northerly component to the wind

Clouds thickening up, the sky cover is down to 2900 feet, down from 12000 feet earlier this past hour. Temp has dropped to 30F/Td of 18F

It does not happen all the time, but I understand your statement. Our coastal is now taking over at 1010mb just south of Cape Hatteras, North Carolina

Never sold on complete snow, but there is a stronger chance now!

Latest GFS is much colder for KCHH (KCQX) - over a foot of snow, latest 12z run!

This is a true arctic airmass overhead right now. Dew point is at 15F this morning. Ocean induced clouds are forming in the northerly surface winds. Again, winds are light to calm at times, but still out of the north. I find it really hard for the winds to turn easterly and scour out this deep dry and cold arctic air. Winds would have to turn out of the east-southeast or southeast or south for their to be appreciable warming.

Ocean Effect Snow Showers have begun to develop over Cape Cod Bay moving southwestward towards Plymouth County shoreline!

HAHAHA

Models latest snow output maps show that the H5 shortwave actually stays in tact and does not get shredded like they had two days ago!

Models beginning to show less mixing for the Cape and is now just for the Cape if any!

GFS shows us how Cape Cod remains all snow, 10:1 ratios with 1.50" of QPF equals 15" for CHH, latest 00z GFS run. I seriously think the deformation band and dry slot will come further southeast as we get closer to the onset. OES contribution and dry slot issues in hand, Cape Cod could start around 5pm EST later this evening, and end around midnight Friday morning! There is a real chance the comma head could bring some wild conditions. If the region does not dry slot, and honestly with a surface track across the BM and even between the BM and ACK I would not expect a changeover, but the H7 and H85 low tracks are a bit concerning moving overhead. There could be a period of sleet.

GFS was right on the benchmark

GFS is less mixing than the 18z run and every run today!

Also I think Blizzard conditions will be rampant from the coastal front westward by about 50 to 75 miles inland!

One factor we have to continue to watch on the coastline is the potential for dynamic cooling if the NAM and mesomodels are correct. They cool the 850mv to 925mb temps rapidly as the low begins to move eastward south of Long Island. We should stay all snow even if they winds change to the northeast and stay that way, unless they change to the east or southeast, we should stay snow.

Congrats everyone northwest of I-95 corridor. I hope you enjoy the sight of a foot of snow, while I bask in 45F rain and winds Thursday!

Snow Map! This is the map for the nor'easter. Cape and Islands will see a few inches and turn to rain, the upper Cape west of Hyannis can see up to 6" or more, while HYA east sees less!

December 16-18th, 2020 Nor'easter Final Call Snow Prediction Map

Damn, do you really see the low moving that far northwest?

No powderfreak, you already got your snow somewhat, let the coastline have our fun. I am going to be upset if the majority of this system is rain!

awesome, love it when Will is making the defense for snow on the Cape!

lift should help cool the surface as 850mb temps near -10C and 925mb near -6C

its north of the H7 low up to 100 miles.