bluewave

We finally got the Southern Stream to become active over the last 7 days. So it delivered our first KU Benchmark storm since 2022 with widespread 10”+ amounts across the Northeast. The benchmark track which is a prerequisite allowed several stations to finally have a 25” season before we even reached February. But since the Western ridge has been so overpowering this winter, the big storm last weekend occurred with a deep trough out West and a transient Southeast ridge. So we needed a relaxation of the ridge for our big storm. One of the December clippers also occurred with a trough out West and a transient Southeast ridge. But that event was Northern Stream dominant so there weren’t widespread 10”+ amounts since the Atlantic and Gulf moisture couldn’t get tapped. The ridge and trough axis was too far east today for the big ocean storm to come closer to the coast. So the Western ridge was just a little too overpowering this weekend. Same theme for much of the winter outside one of our December clippers and the big storm last weekend. The other thing is that getting two 10” events only 7 days apart has only happened once in our area since the 1990s. This was the rare twin 10”+ snowstorms only a few days apart in February 1994. Even during the phenomenal 2010-2018 snowfall run we needed at least several weeks to reload the 10”+ snowfall pattern. The best run from this period was the 60”+ in 33 days from December 2010 into January 2011. But the storms were spaced out at longer than 7 day intervals. Overpowering Western ridge relaxed for the clipper and benchmark storms Late January benchmark track Ridge and trough axis today just a little too far east

Here is another example of how in the past we often had coast to coast cold at durations lasting a month to occasionally the entire DJF winter season. December 2025 was the 39th coldest in the Northeast and the same average temperature of 24.2° as 2017 was. But this is the first time an average Northeast December temperature in this range occurred with all-time warmth in the West near +15° above the long term averages. Back in 2017 we did have some warmth in the Southwest but nothing as extreme as this December was. The other years with that were within about 0.6°which the Northeast was this December had the cold extending to the West Coast. So we can see the warmth expanding out of the Southwest over time and increasing in coverage and magnitude.

That is just one example. The total amount across many locations and timeframes is too vast for me to list in one thread. But I have plenty of more examples for other individual locations and time periods.

This January was much warmer in the Arctic and the CONUS than 1977.

2019 was the warmest January at Rockford, IL to feature a -25° or colder reading with the big temperature swings that month and a high over 50°. Climatological Data for Rockford Area, IL (ThreadEx) - January 2019 Click column heading to sort ascending, click again to sort descending. Sum 788 333 - - 1449 0 2.27 24.9 - Average 25.4 10.7 18.1 -3.7 - - - - 5.9 Normal 29.1 14.5 21.8 - 2019-01-01 32 23 27.5 4.2 37 0 T T 0 2019-01-02 28 22 25.0 1.9 40 0 T T 0 2019-01-03 39 20 29.5 6.5 35 0 0.00 0.0 0 2019-01-04 46 26 36.0 13.2 29 0 0.00 0.0 0 2019-01-05 50 26 38.0 15.3 27 0 0.00 0.0 0 2019-01-06 40 26 33.0 10.5 32 0 T 0.0 0 2019-01-07 51 37 44.0 21.6 21 0 0.53 0.0 0 2019-01-08 44 21 32.5 10.3 32 0 0.00 0.0 0 2019-01-09 23 16 19.5 -2.6 45 0 T T 0 2019-01-10 27 14 20.5 -1.5 44 0 0.00 0.0 0 2019-01-11 29 17 23.0 1.2 42 0 0.00 0.0 0 2019-01-12 31 29 30.0 8.3 35 0 0.28 3.8 0 2019-01-13 32 26 29.0 7.4 36 0 0.01 0.2 4 2019-01-14 26 23 24.5 3.0 40 0 0.00 0.0 4 2019-01-15 33 24 28.5 7.0 36 0 T T 4 2019-01-16 34 26 30.0 8.6 35 0 T 0.0 3 2019-01-17 33 27 30.0 8.7 35 0 T T 3 2019-01-18 30 23 26.5 5.2 38 0 0.17 2.3 2 2019-01-19 24 6 15.0 -6.2 50 0 0.13 4.0 8 2019-01-20 10 -2 4.0 -17.2 61 0 0.00 0.0 8 2019-01-21 14 -7 3.5 -17.7 61 0 0.00 0.0 8 2019-01-22 31 13 22.0 0.8 43 0 0.24 1.5 7 2019-01-23 29 9 19.0 -2.2 46 0 0.23 4.2 11 2019-01-24 22 -2 10.0 -11.2 55 0 T 0.2 13 2019-01-25 1 -11 -5.0 -26.3 70 0 0.05 0.6 12 2019-01-26 5 -21 -8.0 -29.3 73 0 0.07 1.5 14 2019-01-27 8 -15 -3.5 -24.9 68 0 0.10 1.3 14 2019-01-28 21 9 15.0 -6.5 50 0 0.38 4.0 17 2019-01-29 10 -16 -3.0 -24.6 68 0 T 0.2 17 2019-01-30 -13 -25 -19.0 -40.7 84 0 0.00 0.0 17 2019-01-31 -2 -31 -16.5 -38.3 81 0 0.08 1.1 16 Climatological Data for Rockford Area, IL (ThreadEx) - January 1982 Click column heading to sort ascending, click again to sort descending. Sum 594 -47 - - 1735 0 1.58 14.8 - Average 19.2 -1.5 8.8 -13.0 - - - - 6.0 Normal 29.1 14.5 21.8 - 1982-01-01 18 3 10.5 -12.8 54 0 0.00 0.0 3 1982-01-02 34 15 24.5 1.4 40 0 0.28 1.9 3 1982-01-03 34 20 27.0 4.0 38 0 0.18 0.3 4 1982-01-04 33 9 21.0 -1.8 44 0 0.16 1.3 4 1982-01-05 31 6 18.5 -4.2 46 0 0.00 0.0 4 1982-01-06 23 5 14.0 -8.5 51 0 0.08 1.1 4 1982-01-07 5 -10 -2.5 -24.9 67 0 0.00 0.0 5 1982-01-08 15 -10 2.5 -19.7 62 0 0.02 0.3 5 1982-01-09 5 -21 -8.0 -30.1 73 0 0.04 0.4 5 1982-01-10 -5 -27 -16.0 -38.0 81 0 0.00 0.0 5 1982-01-11 3 -6 -1.5 -23.3 66 0 0.00 0.0 5 1982-01-12 10 -8 1.0 -20.7 64 0 0.11 1.1 5 1982-01-13 16 -3 6.5 -15.1 58 0 0.07 0.9 6 1982-01-14 7 -15 -4.0 -25.5 69 0 0.00 0.1 6 1982-01-15 12 -18 -3.0 -24.5 68 0 0.04 0.6 6 1982-01-16 6 -24 -9.0 -30.4 74 0 0.00 0.0 6 1982-01-17 2 -25 -11.5 -32.8 76 0 0.11 2.1 6 1982-01-18 22 0 11.0 -10.3 54 0 0.00 0.0 8 1982-01-19 27 5 16.0 -5.2 49 0 0.00 0.0 7 1982-01-20 28 7 17.5 -3.7 47 0 0.09 0.7 7 1982-01-21 27 23 25.0 3.8 40 0 0.00 0.0 8 1982-01-22 37 18 27.5 6.3 37 0 0.16 0.3 7 1982-01-23 37 -1 18.0 -3.2 47 0 0.00 0.0 7 1982-01-24 -1 -9 -5.0 -26.2 70 0 0.02 0.3 7 1982-01-25 7 -9 -1.0 -22.3 66 0 0.08 2.1 9 1982-01-26 9 -18 -4.5 -25.8 69 0 0.00 0.0 9 1982-01-27 35 8 21.5 0.1 43 0 0.00 0.0 9 1982-01-28 34 6 20.0 -1.5 45 0 0.00 0.0 7 1982-01-29 32 6 19.0 -2.6 46 0 0.13 1.1 6 1982-01-30 31 18 24.5 2.8 40 0 0.00 0.0 7 1982-01-31 20 8 14.0 -7.8 51 0 0.01 0.2 6 Climatological Data for Rockford Area, IL (ThreadEx) - January 1985 Click column heading to sort ascending, click again to sort descending. Sum 712 87 - - 1607 0 1.00 13.4 - Average 23.0 2.8 12.9 -8.9 - - - - 8.6 Normal 29.1 14.5 21.8 - 1985-01-01 31 2 16.5 -6.8 48 0 0.34 3.9 9 1985-01-02 10 -8 1.0 -22.1 64 0 0.00 0.0 9 1985-01-03 19 -14 2.5 -20.5 62 0 0.00 0.0 9 1985-01-04 32 -8 12.0 -10.8 53 0 0.00 0.0 9 1985-01-05 39 24 31.5 8.8 33 0 0.00 0.0 8 1985-01-06 37 24 30.5 8.0 34 0 0.00 0.0 7 1985-01-07 37 28 32.5 10.1 32 0 T T 7 1985-01-08 28 8 18.0 -4.2 47 0 T T 7 1985-01-09 22 8 15.0 -7.1 50 0 0.01 0.1 7 1985-01-10 24 15 19.5 -2.5 45 0 0.11 1.7 8 1985-01-11 20 4 12.0 -9.8 53 0 T T 8 1985-01-12 14 0 7.0 -14.7 58 0 0.00 0.0 8 1985-01-13 28 9 18.5 -3.1 46 0 0.00 0.0 8 1985-01-14 35 4 19.5 -2.0 45 0 0.01 0.3 8 1985-01-15 15 -8 3.5 -18.0 61 0 0.00 0.0 8 1985-01-16 22 11 16.5 -4.9 48 0 0.15 2.2 8 1985-01-17 22 11 16.5 -4.8 48 0 0.14 1.9 10 1985-01-18 25 6 15.5 -5.8 49 0 0.02 0.4 11 1985-01-19 6 -24 -9.0 -30.2 74 0 T T 11 1985-01-20 -5 -26 -15.5 -36.7 80 0 T T 11 1985-01-21 17 -6 5.5 -15.7 59 0 T T 11 1985-01-22 22 12 17.0 -4.2 48 0 T T 10 1985-01-23 27 15 21.0 -0.2 44 0 T T 8 1985-01-24 30 21 25.5 4.3 39 0 0.06 0.9 8 1985-01-25 29 -5 12.0 -9.3 53 0 0.01 0.2 9 1985-01-26 22 -10 6.0 -15.3 59 0 0.00 0.0 9 1985-01-27 30 8 19.0 -2.4 46 0 0.00 0.0 8 1985-01-28 15 -5 5.0 -16.5 60 0 0.00 0.0 8 1985-01-29 22 -6 8.0 -13.6 57 0 0.01 0.2 8 1985-01-30 28 9 18.5 -3.2 46 0 0.14 1.5 7 1985-01-31 9 -12 -1.5 -23.3 66 0 T 0.1 9 Climatological Data for Rockford Area, IL (ThreadEx) - January 2009 Click column heading to sort ascending, click again to sort descending. Sum 695 160 - - 1580 0 0.81 12.6 - Average 22.4 5.2 13.8 -8.0 - - - - 5.1 Normal 29.1 14.5 21.8 - 2009-01-01 31 16 23.5 0.2 41 0 0.00 0.0 1 2009-01-02 30 14 22.0 -1.1 43 0 0.00 0.0 T 2009-01-03 37 16 26.5 3.5 38 0 T 0.0 T 2009-01-04 37 14 25.5 2.7 39 0 0.26 0.0 T 2009-01-05 29 9 19.0 -3.7 46 0 0.00 0.0 T 2009-01-06 31 17 24.0 1.5 41 0 0.06 0.8 T 2009-01-07 28 12 20.0 -2.4 45 0 T 0.2 1 2009-01-08 23 9 16.0 -6.2 49 0 T T 1 2009-01-09 30 12 21.0 -1.1 44 0 0.24 2.7 3 2009-01-10 28 18 23.0 1.0 42 0 0.04 3.8 6 2009-01-11 19 8 13.5 -8.3 51 0 T T 7 2009-01-12 27 7 17.0 -4.7 48 0 0.05 1.7 7 2009-01-13 22 -5 8.5 -13.1 56 0 0.01 0.4 7 2009-01-14 9 -6 1.5 -20.0 63 0 0.12 1.9 8 2009-01-15 -6 -17 -11.5 -33.0 76 0 0.00 0.0 9 2009-01-16 0 -25 -12.5 -33.9 77 0 0.00 0.0 9 2009-01-17 27 0 13.5 -7.8 51 0 T T 8 2009-01-18 17 9 13.0 -8.3 52 0 T 0.1 8 2009-01-19 20 6 13.0 -8.2 52 0 0.02 0.4 8 2009-01-20 19 6 12.5 -8.7 52 0 0.00 0.0 7 2009-01-21 25 10 17.5 -3.7 47 0 0.00 0.0 7 2009-01-22 31 5 18.0 -3.2 47 0 0.00 0.0 7 2009-01-23 27 12 19.5 -1.7 45 0 0.00 0.0 6 2009-01-24 12 -5 3.5 -17.7 61 0 0.00 0.0 6 2009-01-25 11 -5 3.0 -18.3 62 0 0.00 0.0 6 2009-01-26 14 -4 5.0 -16.3 60 0 T T 6 2009-01-27 15 4 9.5 -11.9 55 0 0.01 0.2 6 2009-01-28 16 1 8.5 -13.0 56 0 T 0.3 6 2009-01-29 29 15 22.0 0.4 43 0 T 0.1 6 2009-01-30 16 0 8.0 -13.7 57 0 T T 6 2009-01-31 41 7 24.0 2.2 41 0 0.00 0.0 6 Climatological Data for Rockford Area, IL (ThreadEx) - January 1924 Click column heading to sort ascending, click again to sort descending. Sum 792 90 - - 1566 0 1.27 9.5 - Average 25.5 2.9 14.2 -7.6 - - - - 3.8 Normal 29.1 14.5 21.8 - 1924-01-01 19 -13 3.0 -20.3 62 0 0.00 0.0 5 1924-01-02 24 -4 10.0 -13.1 55 0 T T 5 1924-01-03 21 -6 7.5 -15.5 57 0 0.00 0.0 5 1924-01-04 12 -11 0.5 -22.3 64 0 T T 5 1924-01-05 -11 -25 -18.0 -40.7 83 0 0.00 0.0 5 1924-01-06 23 -19 2.0 -20.5 63 0 0.00 0.0 5 1924-01-07 32 7 19.5 -2.9 45 0 0.00 0.0 M 1924-01-08 44 13 28.5 6.3 36 0 0.00 0.0 M 1924-01-09 41 35 38.0 15.9 27 0 0.16 0.0 M 1924-01-10 38 23 30.5 8.5 34 0 0.41 0.0 M 1924-01-11 24 17 20.5 -1.3 44 0 T T M 1924-01-12 21 7 14.0 -7.7 51 0 T T M 1924-01-13 18 -10 4.0 -17.6 61 0 0.00 0.0 M 1924-01-14 25 9 17.0 -4.5 48 0 T T M 1924-01-15 35 20 27.5 6.0 37 0 0.00 0.0 T 1924-01-16 32 1 16.5 -4.9 48 0 0.68 9.5 M 1924-01-17 12 -15 -1.5 -22.8 66 0 0.00 0.0 M 1924-01-18 20 -8 6.0 -15.3 59 0 T T M 1924-01-19 20 0 10.0 -11.2 55 0 0.00 0.0 M 1924-01-20 6 -12 -3.0 -24.2 68 0 0.00 0.0 M 1924-01-21 2 -21 -9.5 -30.7 74 0 0.00 0.0 M 1924-01-22 36 -7 14.5 -6.7 50 0 0.00 0.0 M 1924-01-23 33 16 24.5 3.3 40 0 0.00 0.0 M 1924-01-24 36 11 23.5 2.3 41 0 0.02 T M 1924-01-25 35 -8 13.5 -7.8 51 0 0.00 0.0 M 1924-01-26 8 -8 0.0 -21.3 65 0 0.00 0.0 M 1924-01-27 25 -6 9.5 -11.9 55 0 0.00 0.0 M 1924-01-28 40 19 29.5 8.0 35 0 0.00 0.0 M 1924-01-29 39 33 36.0 14.4 29 0 0.00 0.0 M 1924-01-30 43 27 35.0 13.3 30 0 0.00 0.0 M 1924-01-31 39 25 32.0 10.2 33 0 T 0.0 T

The magnitude of the temperature swings are greater now than in the old days. In order for the CONUS to have a top 5 to top 10 coldest winter there needs to be extensive cold across a large portion of the CONUS which hasn’t happened since the 1970s. These days we can’t get significant Arctic outbreaks without some extreme Arctic warmth like we have been experiencing this winter. No spots in the CONUS this January will see as extreme a departure for the entire month as portions of the Arctic have.

I would say the pattern this winter fits perfectly with what one would expect from a warmer world. First, the extent of the cold this winter was limited compared to what we used to get from Arctic outbreaks across the Northern Hemisphere. The top 5 cold from late January into early February from the Central and Eastern CONUS will only be of a 10 to perhaps 15 day duration. In the old days we could have 60-90 day durations of top 5 cold like in the late 1970s in the CONUS. Plus the record early late November SSW at the time of the lowest Arctic sea ice extent for the late fall into early winter matches model studies which show a link with low Arctic sea ice when combined with a -QBO. Also notice the all-time record warmth out West this winter instead of coast to coast extended cold like we used to get. The presence of the warmth in proximity to the cold can lead to very large temperature swings in some locations.

That’s what makes this top 5 coldest pattern from January 24th through at least February 2nd for the Central and Eastern CONUS so impressive.

Maybe Walpack was closer to -40° in January 1994 with the great cold air drainage that location gets. Too bad they didn’t have readings there before 2004. It’s significantly colder there than Sussex, NJ with radiational cooling which we have a longer climate record for. Climatological Data for SUSSEX 1 NW, NJ - January 1994 Click column heading to sort ascending, click again to sort descending. Sum 862 86 - - 1263 0 4.34 39.0 - Average 28.7 3.2 16.2 -9.6 - - - - 9.0 Normal 34.9 16.7 25.8 - 1215 0 3.50 11.6 1994-01-01 27 M M M M M 0.00 0.0 1 1994-01-02 40 M M M M M T T T 1994-01-03 45 23 34.0 7.0 31 0 0.00 0.0 T 1994-01-04 25 20 22.5 -4.3 42 0 0.34 4.0 5 1994-01-05 26 18 22.0 -4.7 43 0 M 3.0 7 1994-01-06 32 12 22.0 -4.5 43 0 M 0.0 6 1994-01-07 15 11 13.0 -13.4 52 0 0.07 1.0 5 1994-01-08 15 10 12.5 -13.7 52 0 0.82 7.0 M 1994-01-09 30 7 18.5 -7.6 46 0 T T 8 1994-01-10 34 7 20.5 -5.5 44 0 0.00 0.0 7 1994-01-11 24 -1 11.5 -14.4 53 0 M M 7 1994-01-12 28 12 20.0 -5.8 45 0 0.00 0.0 6 1994-01-13 33 16 24.5 -1.2 40 0 0.39 6.0 10 1994-01-14 38 27 32.5 6.9 32 0 0.00 0.0 M 1994-01-15 35 3 19.0 -6.5 46 0 0.17 2.0 7 1994-01-16 M -8 M M M M T 0.0 6 1994-01-17 14 M M M M M 0.00 0.0 6 1994-01-18 31 4 17.5 -7.8 47 0 1.36 12.0 M 1994-01-19 31 -11 10.0 -15.3 55 0 0.00 0.0 M 1994-01-20 8 -16 -4.0 -29.3 69 0 0.00 0.0 17 1994-01-21 11 -29 -9.0 -34.2 74 0 0.00 0.0 17 1994-01-22 12 -28 -8.0 -33.2 73 0 0.00 0.0 17 1994-01-23 30 4 17.0 -8.2 48 0 0.00 0.0 16 1994-01-24 33 M M M M M 0.00 0.0 16 1994-01-25 47 30 38.5 13.3 26 0 0.00 0.0 16 1994-01-26 34 9 21.5 -3.8 43 0 0.31 4.0 12 1994-01-27 12 -15 -1.5 -26.8 66 0 0.12 M 13 1994-01-28 28 -15 6.5 -18.8 58 0 M M 11 1994-01-29 54 -28 13.0 -12.4 52 0 0.76 M M 1994-01-30 39 19 29.0 3.5 36 0 0.00 0.0 M 1994-01-31 31 5 18.0 -7.5 47 0 0.00 0.0 M https://www.njweather.org/station/79

A great drone video just got posted this morning.

It’s very rare for us to get 3 or more cold months in a row here as has been the case since November. The last time this happened was January to March 2015. Let’s hope we don’t see a rebound like 2015 into 2016 again.

If we had a strong northerly cold air drain down the Hudson Valley like in early February 2023, then NYC wouldn’t have had any trouble getting to 0 to 5°. NYC has always needed the winds to stay up for their coldest readings. The winds were too light to transport the cold into the heat island areas this morning.

My friend took a photo of the frozen Great South Bay yesterday just before landing.

A top 5 coldest January 24th to 30th across the area and much of the Central to Eastern CONUS. Time Series Summary for NY CITY CENTRAL PARK, NY Coldest January 24th to 30th Click column heading to sort ascending, click again to sort descending. 1 1935-01-30 15.0 0 2 1888-01-30 15.6 0 3 1936-01-30 15.9 0 4 2026-01-30 16.9 0 5 1961-01-30 17.4 0 6 1873-01-30 18.4 0 7 1897-01-30 18.5 0 8 1948-01-30 18.8 0 9 1881-01-30 19.2 0 10 2004-01-30 19.4 0

My first 0° since moving up here.