bluewave

Yeah, numerous issues related to the swaying in the stronger winds.

It’s got to be a real experience living in one of these supertalls. The Brooklyn Tower is having the same issues as 432 Park. Very loud noises and more sway than the residents were told about before they bought or rented. Plus this year set the record for days with wind gusts over 40 mph by a wide margin behind all these storms racing through the Great Lakes like what we are going to see a repeat of again the next few days. https://www.instagram.com/reel/DS0cuaxDEzD/?igsh=NDg2cDVkNTFmNWk0

Classic snowpack eater dense fog across the area this morning with only around 0.12 mile visibility at spots like JFK and ISP. Dec 29, 6:51 am 42 41 96 37 SSW 8 0.12 Lt drizzle, Fog

The raw NAM point forecasts from just west of Newark out across NYC and the 5 boroughs were too low for snowfall. Multiple runs only had around 1-2 inches of snow where around 4” verified. So the NAM was overdone on the warm nose. But globals like the GFS and Euro were underdone on this feature and dry slot. So these models were incorrect to forecast warning level snows at times for NYC and points west. No one model is going to be correct about everything. So we have to blend the models to get something closer to reality. This blending is why I went 3-5” for NYC. But areas further east across Long Island where I went 5-8” were more accurately portrayed by other models. Although some NAM runs maintained all snow in these areas. We need a new NAM since the model hasn’t been updated since March 2017. One of its biggest issues is how jumpy it is from run to run. This leads to some not taking anything the model says seriously. Even when the theme that NYC and points west would nit get warning level snows which turned out to be correct.

I can see both of your points. Don is coming more from a letter of the law perspective and you from the spirit of the law. The NAM was trying to show a dry slot and a warm nose between 700-800 MB. While the NAM didn’t get the exact locations of the warm nose and dry slot correct for areas further east, it was correct in the idea that there would be lower accumulations south and west of NYC. The globals really didn’t do well with these features from around NYC and points south and west. I tried a blended approach trying to follow the spirit of what the NAM was trying to say vs the general heavy snowfall signal from the remaining guidance. So this is why earlier in this thread I went 3-5” for EWR-NYC-LGA-JFK and 5-8” for Northern Nassau out into Suffolk. I wasn’t taking the exact NAM run but trying to incorporate what is was implying about lower snowfall risks closer to NYC and points south and west. It would be great if they could replace the NAM with model that is more stable from run to run and show a good solution for the entire region. While maintain the ability to resolve the finer details than a more broad brush global models approach. Perhaps in the future we can develop an AI bridge type model that can incorporate all the models for a great areawide forecast.

The distribution of the snowfall this month between ISP, PHI, and BOS is not what we typically see when Islip has a snowy 10”+ December. This is the first time since 1988 that ISP has 10”+ in December and either Philly or Boston doesn’t have at least 10” also. It’s why we may not be able to use the snowy December winter analogs that followed the other 10” December years on the list. This is due to the 10” at ISP being the first December with two 5”+ clippers that had narrower areas with heavy snow than benchmark coastal snowstorms that also affected Philly or Boston in the other snowy Decembers at Islip. So it will be interesting to see how the rest of the winter plays out at all three locations. All 10”+ snowy Decembers at ISP and the Boston and Philly snowfall 2009…ISP…25.3”….BOS….15.2”….PHI….24.1” 2002…ISP….16.0”….BOS….11.1”……PHI….8.4” 2003…ISP….15.5”…..BOS….21.5”….PHI….6.0” 2010….ISP….14.9”…..BOS…..22.0”…PHI…12.7” 1995….ISP…..13.3”…..BOS…..12.6”….PHI….7.3” 2025….ISP…12.4”…..BOS…..2.3”……PHI….4.5” 1969….ISP….12.0”…..BOS……12.6”….PHI….7.5” 1975…..ISP….11.4”…..BOS…..19.3”……PHI….7.5” 1963…..ISP…..11.0”….BOS….17.7”…….PHI….8.0” 2000….ISP…..10.8”….BOS….4.5”….…PHI…..10.5” 2008….ISP…..10.4”….BOS….25.3”…..PHI…..0.4” 1988…..ISP…..10.4”….BOS….3.7”……PHI…..0.4”

Pretty wild ski conditions in Japan.

It’s only not relevant if you ignore the warming temperatures since then.

That’s due to the weather records not going back far enough in time on Long Island. Other spots like Newark with records back as far as the 1840s showed that something much closer to wall to wall cold and snow was the norm. The 30 year average seasonal snowfall at Newark was 43.7” with an average winter temperature of 30.4”.

We have had longer lasting December snowpack in the past with other 10”+ snowfall Decembers on Long Island without a big warm up and rain following the heavier snows. But these warm ups and rain following the heavier snows have become more common in December and the other winter months that we have had heavier snows. Unfortunately, Long Island weather records don’t go back as far as other spots across the region. But the snowfall this December isn’t that far from what used to be normal at spots with longer periods of record in the past colder climate era. Those colder era Decembers didn’t have the magnitudes of the warm ups with rain. So they had better snowfall retention for what fell relative to today.

50°+ warm ups with or without rain have become much more common prior to and following snow events here than they used to be.

I am comparing it to the old days when we would more extended snowcover with not so many warm ups with rain in between.

This has to be one of the most unusual December patterns that we have ever seen. The record low Arctic sea ice near the Kara and Barents seas has been linked to stratospheric warming events. 2025 marks one of the earliest SSWs on record. It’s also possible that this is our first December with two distinct 4-8” clipper snow events. Plus I am not even sure when the last time was that there were two 4-8” clipper events only two weeks apart during December to March. So I am not really sure yet what if anything this December will say about the rest of the winter. Since we have never had a December pattern like this before. Also note how each of the clipper events is being followed by a strong Great Lakes cutter with rain and a quick warm up.

This is probably one of the best hourly snowfall rates in CT last several years.

Really beautiful event here just east of the HVN ASOS. It came in as a very heavy wall of snow in the evening. We had 2” per hr rates for the first few hours. Then the rates decreased. Finished up here with a very respectable 5.5”.

This storm will be the test for whether they can finally discontinue the NAM. The NAM was the only model which could see the warm nose at 850 mb to 750 mb. None of the other models were very good at this. The NAM has sleet mixing in around EWR-NYC-LGA-JFK. But keeps it all snow from Suffolk NW back into SW CT and interior SE NY. So out of respect for the NAM, I will go 3-5” around EWR-NYC-LGA-JFK and 5-8” Northern Nassau to Suffolk.

Maybe the models easing up a bit on the TPV press early Jan from previous runs may allow the Southern Stream to come more into play with the +TNH and continuing -NAO.

Very impressive gradient in the Dakotas.

I think the last time Orange County had widespread 20”+ was back in December 2002. Monthly Data for December 2002 for Orange County, NY Click column heading to sort ascending, click again to sort descending. GARDNERVILLE COOP 20.1 PORT JERVIS COOP 34.0 WALDEN 1 ESE COOP 22.5 WEST POINT COOP 30.5

Models not quite as cold for the end of December and the start of January as prior runs with the core of the cold now forecast to stay to our north.

This season is going to be an interesting case study for snowy La Niña Decembers across the NYC Metro region and the rest of the season. With the storm coming in next few days, December 2025 will rank in our snowier La Niña December list of years. Most of the time these seasons got to 25”+ from Newark out to Islip. But the way we are getting this snowy December is different from the past La Niña cases. Unusually early stratospheric disruption with the record low sea ice in the Kara and Barents. The forecast is calling for a reversal of this pattern in the stratosphere after the first week of January. So it will be interesting to see if we follow up later in the season with more snow getting us over the 25” mark from Newark out to Islip. My guess is that we would probably need at least one NESIS KU event with a rapidly deepening low near the benchmark to pull this off. Since we haven’t reached 25”+ without at least one KU NESIS storm in the last 30 years. But this storm track has been inactive since January 2022 with all our snow this December coming with an unusually snowy clipper snowfall pattern that we haven’t seen in many years. The overall 500 mb pattern leading to this is quite unique for December. It doesn’t match previous Decembers. So with all the unusual influences this month, it’s difficult to say for sure we will repeat the past winter snowfall outcomes following snowy La Niña Decembers. But we can say for sure that December 2025 will go into the books as one of the our coldest and snowiest in a long time regardless of what happens after the first week of January.

The Euro is showing this coming in as a wall of heavy snow scenario where the best spots for banding can pick up 3-6” of snow in 3-4 hours with excellent rates.

The ensemble mean forecasts always kept the warmest to our SW which isn’t a surprise. But the 26th through the end of the month will verify several degrees colder. The warm up during the 17th to the 25th did beat expectations on the warmest few days which has been a common occurrence since 2011 and even prior to that. The -NAO is actually linking up with the Southeast Ridge this weekend which wasn’t originally forecast. You can see how much the models changed for Saturday from the earlier runs. But the cold high over New England is leading to a colder and snowier solution for a change. The last few years when this happened featured warmer storm tracks due to the lack of a cold high over New England. New run more -NAO linkage with Southeast ridge for rare favorable solution Old run Southeast ridge and -NAO separate