bluewave

Yeah, the 7 station average for January so far would be a little above average in 81-10 normals. We are currently running -0.6 in 91-20 averages. The warmth in Canada has worked down into the Northeast as Caribou is +4.8 so far. Same pattern as recent years with the coldest departures going to our west and south. EWR….-0.6 NYC….-2.4 JFK…..+0.5 LGA…..-2.2 HPN….+1.0 BDR….-0.4 ISP……-0.1

The wind has had more to do with how cold it has felt the last few days. Plus the first week of January is starting colder than the last two years. But it’s warm compared to how cold January 1st-7th in 2018 and 2014 were. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending January 1-7 average temperature 2025-01-07 33.0 0 2024-01-07 36.2 0 2023-01-07 49.5 0 2022-01-07 37.6 0 2021-01-07 38.1 0 2020-01-07 41.2 0 2019-01-07 40.1 0 2018-01-07 16.4 0 2017-01-07 35.6 0 2016-01-07 32.9 0 2015-01-07 32.7 0 2014-01-07 24.0 0

New Brunswick went +4.5 last February with 16.5” of snow due to the record STJ and borderline super El Nino in mid-February allowing the Northern Stream to relax. So unless the monthly average temperature is above 40° in January and February, it’s always cold enough to snow this year. But December and March are different as +5 patterns will usually be too warm for snow. So for us storm tracks are more important than departures in January and February. Climatological Data for New Brunswick Area, NJ (ThreadEx) - February 2024 Click column heading to sort ascending, click again to sort descending. Sum 1381 820 - - 777 0 1.90 16.0 - Average 47.6 28.3 37.9 4.5 - - - - 0.9 Normal 42.8 24.0 33.4 - 885 0 2.97 9.3 2024-02-01 40 29 34.5 3.2 30 0 0.00 0.0 0 2024-02-02 48 30 39.0 7.6 26 0 0.12 0.0 0 2024-02-03 44 32 38.0 6.5 27 0 0.08 0.0 0 2024-02-04 47 27 37.0 5.4 28 0 0.00 0.0 0 2024-02-05 49 25 37.0 5.3 28 0 0.00 0.0 0 2024-02-06 48 23 35.5 3.6 29 0 0.00 0.0 0 2024-02-07 45 24 34.5 2.5 30 0 0.00 0.0 0 2024-02-08 49 26 37.5 5.4 27 0 0.00 0.0 0 2024-02-09 56 30 43.0 10.7 22 0 0.00 0.0 0 2024-02-10 60 37 48.5 16.1 16 0 0.00 0.0 0 2024-02-11 59 41 50.0 17.4 15 0 0.00 0.0 0 2024-02-12 48 33 40.5 7.7 24 0 0.00 0.0 0 2024-02-13 48 32 40.0 7.1 25 0 0.62 4.0 4 2024-02-14 43 30 36.5 3.4 28 0 0.14 1.0 2 2024-02-15 38 23 30.5 -2.8 34 0 0.00 0.0 2 2024-02-16 42 26 34.0 0.5 31 0 0.00 0.0 1 2024-02-17 44 30 37.0 3.3 28 0 0.38 11.0 11 2024-02-18 37 18 27.5 -6.4 37 0 T T 3 2024-02-19 42 24 33.0 -1.1 32 0 0.00 0.0 2 2024-02-20 43 23 33.0 -1.3 32 0 0.00 0.0 1 2024-02-21 41 20 30.5 -4.0 34 0 0.00 0.0 0 2024-02-22 43 23 33.0 -1.7 32 0 0.00 0.0 0 2024-02-23 50 29 39.5 4.5 25 0 0.14 0.0 0 2024-02-24 48 36 42.0 6.8 23 0 0.01 0.0 0 2024-02-25 45 20 32.5 -2.9 32 0 0.00 0.0 0 2024-02-26 42 25 33.5 -2.2 31 0 0.00 0.0 0 2024-02-27 56 32 44.0 8.1 21 0 0.00 0.0 0 2024-02-28 63 42 52.5 16.3 12 0 0.21 0.0 0 2024-02-29 63 30 46.5 10.2 18 0 0.20 0.0 0

At this point the definition of a good season in NYC would be going over 10” and reverting to the 2020s decadal mean around 14.2”. Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 0.0 T 2.6 4.4 7.1 0.1 T 14.2 2019-2020 0.0 0.0 2.5 2.3 T T T 4.8 2020-2021 0.0 0.0 10.5 2.1 26.0 T 0.0 38.6 2021-2022 0.0 T 0.2 15.3 2.0 0.4 0.0 17.9 2022-2023 0.0 0.0 T T 2.2 0.1 0.0 2.3 2023-2024 0.0 T T 2.3 5.2 T 0.0 7.5

The Northern Stream of the Pacific Jet has just been too overpowering. So we have continued the cutter, hugger, and suppressed Southern Stream storm tracks. If this was an El Niño with a STJ further south near the Baja then we would probably all be in double digit snowfall by now. It would have carved out more of a trough near the Tennessee Valley. Hopefully, we can get some relaxation of this theme later this month.

NYC and surrounding areas are on the lower side of La Niña seasonal snowfall by January 10th since 1980. The best La Ninas are usually frontloaded by nature. We are behind 2022 but ahead of 2012. NYC La Niña snowfall by January 10th 2025…3.7” 2023…T 2022…6.0” 2021…10.5” 2018…17.5” 2017….9.5” 2012….2.9” 2011…21.8” 2009…7.0” 2008…2.9” 2006…9.7” 2001…15.2” 1999…4.5” 1996…37.2” 1989….5.3” 1986….0.9” 1985….7.0” 1984….5.4”

Yeah, a bunch of individual lows under the block feeding into the big gyre. It may take the transient Southeast Ridge in a little over 10 days to finally weaken it. Then it looks like we get a vortex consolidating closer to Hudson Bay out toward day 15.

One of the most expansive 50/50 lows that we have seen so far this decade with high pressure pressing in from the west.

Another day with the highs beating guidance with many spots getting above 32° today.

Yeah, hard to believe we got such an amazing 24 day stretch of winter following a December than was warmer than most Novembers. Maximum 24-Day Total Snowfall for JFK INTERNATIONAL AIRPORT, NY Click column heading to sort ascending, click again to sort descending. 1 40.8 1961-02-07 0 - 40.8 1961-02-06 0 - 40.8 1961-02-05 0 - 40.8 1961-02-04 0 2 39.8 1961-02-08 0 3 38.5 2016-02-15 0 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Feb Click column heading to sort ascending, click again to sort descending. 1 1963 -2 0 2 1961 -1 0 3 1967 0 0 4 2016 1 0 5 1979 2 0

It’s ironic that one of our greatest 24 day winter stretches occurred after the +13.3 December.

It was actually one of our most impressive 3 to 4 week winter periods of all-time with a 30” snowfall in spots and then another 10”+ in early February and then the first below 0° in NYC since 1994.

Much weaker Pacific Jet in 90-91 so we were still able to reach average snowfall even if it was a mild winter by the averages in those days. The pattern really flipped warmer in Janaury 1990 with the amped up MJO. December 1989 into January 1990 was one of the strongest MJO driven patterns of that era.

1990-1991 wasn’t too bad as it was of those more frequent near average winters for snowfall close to 25” following the previous 2 lower seasons.

We had multiple 3-6” events around our big 1980s Arctic Outbreaks. Even if NYC didn’t make it to exactly 6”, several spots around the area from NNJ out to Suffolk did. So the cold and dry during the 1980s was a bit of a misnomer. While it was true that the big 12”+ KU events were a rarity back then , we had multiple seasons with close to 25” average in the 70s and 80s without one. Since it was cold enough back then to get to average with a bunch of small to moderate events. With the warmer winters since the 1990s, a KU has been become a prerequisite for average snowfall. These days we just don’t have enough sustained cold to get to average with just small to moderate events.

We are coming up on the 40th anniversary of one of the greatest Arctic outbreaks of the late 20th Century. It was one the most impressive displays from the Long Beach Boardwalk of Arctic Seasmoke plus multiple steamnadoes over the ocean. I was out on the boardwalk with -2° temperatures and 40 to 50 mph gusts. One of the few times I got to experience a below 0° in morning and afternoon temperatures in the single digits. We had a 6” snowstorm a few days earlier with highs below freezing ratio fluff. Then another 6” with a few events a week later. So our 80s Arctic outbreaks usually had at least some snow and not cold and dry. https://www.wunderground.com/history/daily/us/ny/new-york-city/KJFK/date/1985-1-21

Back in October I was pointing out the potential PNA mismatch signal for December which worked out. But I also mentioned that other factors weren’t lining up like they did as recently as 2020 and 2017. As it turns out the Northern Stream of the Pacific was among the strongest we have ever seen with such a positive +PNA. So this lead to the warmer and less snowy outcome than most of the past +PNA La Niña Decembers. La Niña Decembers with strong +PNA patterns 2024…PNA…+1.70….NYC….avg temp…38.2°….snowfall…2.8” 2020…+1.58….39.2°….10.5” 2017….+0.89…35.0°…..7.7” 2005…+1.38….35.3…..9.7” 2000….+1.23…31.1°…..13.4” 1995…..+0.92…32.4°….11.5” 1985…..+1.39….34.2°….0.9” 1963……+1.77….31.2°….11.3”

Big windchill factor day with highs below freezing and wind gusts over 40 mph.

This is really cool.

Yeah, it will be interesting to see how low we can get the winter cold departure by January 25th. The EPS and GEFS weeklies want to bring in a milder pattern by the end of January into February. So the winter negative temperature departures around our area may get smaller as February progresses. Having a cold enough departure by then may raise the possibility of our first colder winter here in 10 years. Even if it’s strictly a function of the warmer 91-20 climo and could be warmer than normal against the old 81-10 normals. But you never know for sure since we have seen several late winter La Niña periods overperform expectations and boost the winters above average based on how mild the finish was. Getting 9 warmer winters in a row is so statistically rare that you would think that one of these years we would get a break even if only by a small margin.

It would have been epic if that took a classic BM track instead. Had heavy snow during the day. Then the warm up and rain and big tidal surge which floated away the whole snowpack which was really compacted. The mini icebergs settled to the ground after floating around the streets and froze into cement blocks with the rapidly falling temps and flash freeze next morning.

Maybe the best -EPO of the winter so far if we can get some coupling with the strat.

I just try to be grateful these days for any amount of snow we get here.

Yeah, the CMC would be a happy compromise between the GFS and Euro.

Yeah, that OP run is a big outlier in today’s 12z model suite.