Tatamy

A look at the surface winds during the course of this storm as shown on these models paints a revealing picture of why LI and most of NYC is mainly rain while the rain / snow line is right near the CT coast. As the event begins those surface winds are mainly from the east. That locks in the slightly milder air mass coming in from off the warm ocean. With time those winds do back around to north- northeast and north and increase. Only then can the BL cool enough in order for snow flakes to reach the surface. By then the heaviest precipitation has moved to the east. The only way this gets done sooner is if precipitation falls at much heavier rates. I saw this happen many times when I lived out on the island. For the sake of those of you out on the island hopefully this event evolves differently.

March 1993 was a triple phaser. I am not so sure that the presence of the warm pool off of the coast would have changed the track on that one.

18z GFS torches us for the middle part of next week.

76-77 was done by mid February. It was about 6 weeks of excitement.

I was out on LI last week. I was amazed by how much color was still on the trees and vegetation. In decades past this was done by second week of November.

In so far as LI goes you would need SST’s below 45 in order for the atmosphere (with cold or cooling temperatures aloft) to overcome onshore flow during a winter event.

It’s depicting an elevation event this run.

Thank you for your response. Do you know of a site where the output from these sites can be accessed in real time?

Chris - You mentioned the intensity of these echoes produced by Nemo. Most of the radar obs that we speak of relating to weather comes from the NWS network of Dual-Pol Doppler sites. The FAA also has a network of 80 radar sites (CARSR) around the country to serve its purposes. I have read that these sites have the capability to monitor the weather and report it in the NWS six level format. Do you know how the functionality of these sites/equipment compares to that of the NWS?

Regarding your second point those that are looking for snowstorms need to look at the last two runs of the CFS on Pivotal (snow depth).

Activity is moving very rapidly to the east. Snow squalls currently in the Stroudsburg area near the Water Gap. Squall also moving through the Reading area. From radar I would guess that you would get no more than 5-10 minutes of snow in a burst when these move through.

There are snow squalls moving east on a line from about Hazleton to Scranton.

You’re going to have to wait on this one as there is nothing currently reaching the ground from the Harrisburg area and I 81 on east.

I will share a personal experience. Many years ago I was driving my sister back to school at SUNY Oswego from LI after Christmas. We drove up I-81 to the Syracuse area and proceeded to turn onto 481 to complete the trip. It was late in the day and the sun was hitting the side of towering CU that made up the band. It would have a great picture if I had a phone camera (this was 40 years ago so these were not yet invented). We proceeded to drive into it and road conditions rapidly deteriorated. It turned dark and the snow was falling so hard that it was blinding in the headlights. The flakes were large and fluffy. I found that since a plow had recently passed the black top was visible. I ended up driving with the headlights off for a time and could actually see a lot better with the blacktop as a back drop. We eventually had to turn off due to the conditions. FWIW Reed Timmer is chasing the band near Buffalo so you can follow him.

Great link to the Lake Effect snow up in Buffalo. This is a link to the traffic cams along I-190 in the city. You can see some areas that are experiencing whiteouts along the highway while other areas are up to one mile with the band in the distance. https://www.thruway.ny.gov/travelers/map/text/twytextcameras.cgi?region=BUI190

This event is showing up in a lot of the 12z runs as Walt has noted. The area most likely to be impacted looks to be western and NW NJ and adjacent PA. This looks to be tied to the passage of a Vorticity max through those areas tomorrow evening.

There are a lot of accounts from people who have experienced just that up there. Plenty of videos on social media showing this as well (Chaser videos specifically).

Looks like a sunny morning in progress. According to the morning disco from Buffalo NWS with the approach of a shortwave this evening the flow will back around to the SW. This will initiate the setup of the band that will impact Buffalo. The snow is expected to begin around 8 PM there.

Temps along Fire Island and on the east end have already jumped into the mid to upper 50s this morning.

Had a quick burst of snow which left a coating. Has now changed back to rain. 33/31

Light rain mixed with ice pellets here. 40/27

18z GFS for Black Friday. It will be very interesting to see how this pattern evolves.

Very true on the elevation factor. MPO in the Poconos at 2000 ft is forecast to get 1-3" along with 0.1 - 0.3" of ice accum.

Mt. Holly issues a WWA for the Poconos and Sussex Cty in NJ. This will be a prototypical north of Blue Mountain (PA) north and west of I80/I287 (NJ) early season event.

Freezing Rain potential with the Tuesday / Wednesday event off the 0z NAM