bluewave

We will need a return to the BM KU snowstorms well before 28-29 for PHL, NYC, and BOS to avoid their lowest snowfall decade. Monthly Total Snowfall for Philadelphia Area, PA (ThreadEx) Click column heading to sort ascending, click again to sort descending. Mean T T 1.2 4.7 3.6 0.1 0.0 8.9 2024-2025 0.0 T 0.3 4.6 M M M 4.9 2023-2024 0.0 T T 8.0 3.2 0.0 0.0 11.2 2022-2023 T 0.0 T T 0.3 T 0.0 0.3 2021-2022 0.0 0.0 T 12.1 0.4 0.4 0.0 12.9 2020-2021 0.0 0.0 6.6 3.0 14.3 0.0 0.0 23.9 2019-2020 0.0 T 0.1 0.2 T 0.0 0.0 0.3 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Mean 0.0 T 2.7 4.2 7.1 0.1 T 12.8 2024-2025 0.0 0.0 2.8 3.0 M M M 5.8 2023-2024 0.0 T T 2.3 5.2 T 0.0 7.5 2022-2023 0.0 0.0 T T 2.2 0.1 0.0 2.3 2021-2022 0.0 T 0.2 15.3 2.0 0.4 0.0 17.9 2020-2021 0.0 0.0 10.5 2.1 26.0 T 0.0 38.6 2019-2020 0.0 0.0 2.5 2.3 T T T 4.8 Monthly Total Snowfall for Boston Area, MA (ThreadEx) Click column heading to sort ascending, click again to sort descending. Mean 0.7 T 5.3 11.3 7.0 0.6 0.2 23.9 2024-2025 0.0 0.0 5.7 6.8 M M M 12.5 2023-2024 0.0 T 0.2 9.0 0.5 T 0.1 9.8 2022-2023 0.0 T 1.0 6.9 3.6 0.9 0.0 12.4 2021-2022 0.0 T 0.4 36.2 15.3 2.1 T 54.0 2020-2021 4.3 T 13.0 5.8 15.3 0.1 0.1 38.6 2019-2020 0.0 T 11.5 3.1 0.5 T 0.7 15.8

Hopefully, NYC can get over 10” this season. The La Niña seasonal average for NYC with under 10” by 01-31 has been 14.3” since 1970. The only La Niña year that they couldn’t do it was 2012. NYC La Niña snowfall by 01-31 under 10” and seasonal total 2025….5.8”……….? 2012….7.2”………7.4” 2008…2.9”….….11.9” 2000…9.5”……..16.3” 1999….6.5”…….12.7” 1986….3.1”…….13.0” 1976….7.9”….…17.3” 1975….2.2”……13.1” 1972….2.8”…..22.9” AVG…………….14.3”

The record cold is very narrowly focused this time around as February 1895 was the 3rd coldest on record for the entire CONUS. Contiguous U.S. Average Temperature February February 1936 25.23°F 1 -8.59°F February 1899 25.50°F 2 -8.32°F February 1895 26.60°F 3 -7.22°F February 1929 26.92°F 4 -6.90°F February 1905 26.94°F 5 -6.88°F

The 1895 event had a much colder pattern leading up to that record snow. This one had the cold come after the snow was on the ground due to the great radiational cooling conditions. So the record cold this time had a much smaller footprint in the CONUS than how extensive the cold was in 1895.

The late January cold timing is similar to some past La Ninas. While the magnitude of this cold was less than the January 20 to 31 La Niña periods in 2011, 2000, 1985, 1984, and 1976, the snowfall has been much lower. Those La Niña years had some impressive late January snowstorms also to go along with the cold.

The common thread has been the lack of BM KU snowstorms. The track earlier in the winter was through the Great Lakes and most spots had a wetter than normal December with 4 to 6 inches of rain. This month the storm track has been suppressed south with a very dry pattern here. The one snow event the other day event had the rain-snow line and low pressure hug the coast at the start in the 40s. So we lost some accumulation to rain at the start and snow melting. The risk going forward is that we only get another short window of opportunity heading into early February. This is when the EPO shifts from negative to positive. Then the storm track may shift back to the Great Lakes again beyond that point as we eventually get the Southeast Ridge to return as is typical for La Nina Februaries.

I believe this is the first time the area around Sussex, NJ dropped below -10 since 1-31-19. 2019-01-31 16 -11 2.5 -24. 2019-01-31 25 -10 7.5 -18.0 https://www.weather.gov/wrh/timeseries?site=KFWN&hours=72 Time Series Summary for SUSSEX 1 NW, NJ - Dec through Feb Click column heading to sort ascending, click again to sort descending. 1 1993-1994 -29 36 2 1960-1961 -25 0 3 1911-1912 -24 3 4 1966-1967 -23 0 5 1980-1981 -22 0 - 1967-1968 -22 2 6 1983-1984 -21 1 7 1947-1948 -20 0 - 1942-1943 -20 0 8 1978-1979 -18 1 - 1915-1916 -18 0 9 1987-1988 -17 5 - 1962-1963 -17 1 - 1933-1934 -17 2 - 1898-1899 -17 1 10 1924-1925 -16 5 11 2014-2015 -15 0 - 1986-1987 -15 2 - 1984-1985 -15 5 - 1969-1970 -15 1 - 1961-1962 -15 5 - 1934-1935 -15 0 12 2008-2009 -14 2 - 1970-1971 -14 1 - 1965-1966 -14 0 - 1941-1942 -14 0 - 1937-1938 -14 1 - 1919-1920 -14 2 13 1950-1951 -13 0 - 1909-1910 -13 1 14 2004-2005 -12 8 - 1989-1990 -12 3 - 1963-1964 -12 0 - 1913-1914 -12 0 - 1904-1905 -12 31 15 2018-2019 -11 0 - 1977-1978 -11 3 - 1976-1977 -11 2 - 1927-1928 -11 4 - 1922-1923 -11 4 - 1895-1896 -11 1 - 1893-1894 -11 32

Still one of my favorite blizzards of all time. Probably the most lightning that I have seen with a snow event. That storm with the 3 consecutive record lows would have been an impressive April event even during the Little Ice Age.

But you knew it wouldn’t take long for the inevitable sun angle posts.

Almost reminds me of October 2011 when NYC had the early month near record 84° warmth followed by the all-time biggest October snowstorm later in the month. 10/9 86 in 1916 84 in 2011 84 in 1990+ Climatological Data for NY CITY CENTRAL PARK, NY - October 2011 Click column heading to sort ascending, click again to sort descending. Sum 1977 1563 - - 255 17 6.09 2.9 - Average 63.8 50.4 57.1 -0.8 - - - - 0.0 Normal 64.5 51.4 57.9 - 240 22 4.38 0.1 2011-10-01 67 50 58.5 -5.0 6 0 0.39 0.0 0 2011-10-02 64 50 57.0 -6.1 8 0 0.06 0.0 0 2011-10-03 58 48 53.0 -9.7 12 0 0.05 0.0 0 2011-10-04 63 49 56.0 -6.3 9 0 0.00 0.0 0 2011-10-05 71 53 62.0 0.1 3 0 0.00 0.0 0 2011-10-06 67 47 57.0 -4.5 8 0 0.00 0.0 0 2011-10-07 66 48 57.0 -4.1 8 0 0.00 0.0 0 2011-10-08 77 54 65.5 4.7 0 1 0.00 0.0 0 2011-10-09 84 60 72.0 11.6 0 7 0.00 0.0 0 2011-10-10 81 61 71.0 11.0 0 6 0.00 0.0 0 2011-10-11 73 62 67.5 7.9 0 3 0.00 0.0 0 2011-10-12 63 58 60.5 1.2 4 0 0.45 0.0 0 2011-10-13 66 58 62.0 3.1 3 0 0.34 0.0 0 2011-10-14 70 57 63.5 5.0 1 0 1.02 0.0 0 2011-10-15 65 54 59.5 1.3 5 0 0.00 0.0 0 2011-10-16 66 54 60.0 2.2 5 0 0.00 0.0 0 2011-10-17 65 57 61.0 3.5 4 0 T 0.0 0 2011-10-18 68 54 61.0 3.9 4 0 0.01 0.0 0 2011-10-19 62 60 61.0 4.2 4 0 1.12 0.0 0 2011-10-20 67 54 60.5 4.1 4 0 0.01 0.0 0 2011-10-21 56 50 53.0 -3.1 12 0 0.00 0.0 0 2011-10-22 60 47 53.5 -2.3 11 0 0.00 0.0 0 2011-10-23 59 50 54.5 -0.9 10 0 0.00 0.0 0 2011-10-24 61 50 55.5 0.4 9 0 0.00 0.0 0 2011-10-25 62 50 56.0 1.2 9 0 0.00 0.0 0 2011-10-26 62 51 56.5 2.1 8 0 0.00 0.0 0 2011-10-27 61 38 49.5 -4.6 15 0 0.63 0.0 0 2011-10-28 49 36 42.5 -11.3 22 0 0.00 0.0 0 2011-10-29 45 33 39.0 -14.5 26 0 2.00 2.9 0 2011-10-30 46 33 39.5 -13.7 25 0 0.01 T 0 2011-10-31 53 37 45.0 -7.8 20 0 0.00 0.0 0

Really rare storm track with just enough cold in place along the Gulf Coast. The pattern leading up to the event wasn’t that cold in the area.There was an 81° record high a few weeks ago. It has been much warmer than the February 1895 was ahead of the previous record snow. Also notice how warm the nearby Gulf has been. 1/5 81 in 2025 79 in 2005 77 in 1955 Climatological Data for Baton Rouge Area, LA (ThreadEx) - January 2025 Click column heading to sort ascending, click again to sort descending. Sum 1183 758 - - 328 3 1.94 0.0 Average 59.2 37.9 48.5 -3.2 - - - - Normal 61.9 41.4 51.7 - 275 9 4.22 2025-01-01 64 42 53.0 1.0 12 0 0.00 0.0 2025-01-02 65 39 52.0 0.1 13 0 0.00 0.0 2025-01-03 70 48 59.0 7.2 6 0 0.00 0.0 2025-01-04 65 45 55.0 3.2 10 0 T M 2025-01-05 81 52 66.5 14.8 0 2 0.40 0.0 2025-01-06 52 33 42.5 -9.2 22 0 0.00 0.0 2025-01-07 49 30 39.5 -12.1 25 0 0.00 0.0 2025-01-08 48 30 39.0 -12.6 26 0 0.00 0.0 2025-01-09 46 31 38.5 -13.1 26 0 0.04 M 2025-01-10 50 40 45.0 -6.6 20 0 1.15 M 2025-01-11 51 33 42.0 -9.5 23 0 0.00 0.0 2025-01-12 51 31 41.0 -10.5 24 0 0.35 M 2025-01-13 65 42 53.5 1.9 11 0 0.00 0.0 2025-01-14 59 34 46.5 -5.1 18 0 0.00 0.0 2025-01-15 62 48 55.0 3.4 10 0 T 0.0 2025-01-16 67 37 52.0 0.4 13 0 0.00 0.0 2025-01-17 64 35 49.5 -2.2 15 0 T M 2025-01-18 78 53 65.5 13.8 0 1 T 0.0 2025-01-19 53 31 42.0 -9.8 23 0 0.00 0.0 2025-01-20 43 24 33.5 -18.3 31 0 0.00 0.0 2025-01-21 M M M M M M M M 2025-01-22 M M M M M M M M 2025-01-23 M M M M M M M M 2025-01-24 M M M M M M M M 2025-01-25 M M M M M M M M 2025-01-26 M M M M M M M M 2025-01-27 M M M M M M M M 2025-01-28 M M M M M M M M 2025-01-29 M M M M M M M M 2025-01-30 M M M M M M M M 2025-01-31 M M M M M M M M Climatological Data for Baton Rouge Area, LA (ThreadEx) - February 1895 Click column heading to sort ascending, click again to sort descending. Sum 1285 797 - - 493 0 5.79 12.5 Average 53.5 33.2 43.4 -12.5 - - - - Normal 66.6 45.3 55.9 - 279 25 4.42 1895-02-01 58 41 49.5 -3.7 15 0 0.70 0.0 1895-02-02 48 38 43.0 -10.4 22 0 0.02 0.0 1895-02-03 54 37 45.5 -8.1 19 0 T 0.0 1895-02-04 56 36 46.0 -7.8 19 0 0.00 0.0 1895-02-05 56 36 46.0 -7.9 19 0 0.03 0.0 1895-02-06 70 M M M M M T 0.0 1895-02-07 M 17 M M M M 0.00 0.0 1895-02-08 36 11 23.5 -31.0 41 0 0.00 0.0 1895-02-09 37 20 28.5 -26.2 36 0 0.00 0.0 1895-02-10 40 34 37.0 -17.9 28 0 0.56 0.0 1895-02-11 54 33 43.5 -11.6 21 0 2.15 0.0 1895-02-12 38 30 34.0 -21.4 31 0 0.00 0.0 1895-02-13 39 25 32.0 -23.6 33 0 0.00 0.0 1895-02-14 34 34 34.0 -21.8 31 0 0.60 6.0 1895-02-15 33 24 28.5 -27.5 36 0 0.65 6.5 1895-02-16 37 26 31.5 -24.7 33 0 T T 1895-02-17 47 20 33.5 -22.9 31 0 0.00 0.0 1895-02-18 62 28 45.0 -11.7 20 0 0.00 0.0 1895-02-19 55 36 45.5 -11.4 19 0 T 0.0 1895-02-20 60 28 44.0 -13.1 21 0 0.00 0.0 1895-02-21 M M M M M M 0.00 0.0 1895-02-22 M M M M M M 0.00 0.0 1895-02-23 M M M M M M 1.08 0.0 1895-02-24 73 47 60.0 2.0 5 0 0.00 0.0 1895-02-25 73 49 61.0 2.8 4 0 0.00 0.0 1895-02-26 72 50 61.0 2.6 4 0 0.00 0.0 1895-02-27 77 49 63.0 4.4 2 0 0.00 0.0 1895-02-28 76 48 62.0 3.1 3 0 0.00 0.0

It’s been an interesting progression. The dry pattern in NJ actually started last June while places to the east were still wet from the record rains since July 23. Then everyone got dry from August 21st to November 21st. Spots from LI into CT were very wet with 10”+ rainfall totals through New Year’s Eve. January has been dry across the area as it’s tough to get much precipitation here with the Southeast Ridge suppressed. My guess is that February will be wetter than January was as the Southeast Ridge flexes like it usually does with La Niña Februaries. But if the storm track shifts back too far toward the Great Lakes, then the wettest relative to the means may go to our west. If that’s the case, then we’ll really need a wet spring in order to avoid this drought carrying over into next summer.

I believe this was the coldest at Walpack since January 2018 when the got down to -16°. https://www.njweather.org/data Walpack NJ 2025-01-21 Mesonet 15 -15 Walpack NJ 2018-01-01 Mesonet 19 -16

We actually had one of our coldest Februaries that month around 24° in NYC. So the record cold is much less extensive this time around with the core going to our south and west again. More narrowly focused Arctic outbreaks covering smaller geographic regions has become the new normal. Just like we were much colder during past instances then when Texas got record cold compared to February 2021. Climatological Data for NY CITY CENTRAL PARK, NY - February 1895 Click column heading to sort ascending, click again to sort descending. Sum 865 495 - - 1132 0 0.46 9.0 Average 30.9 17.7 24.3 -11.6 - - - - Normal 42.2 29.5 35.9 - 816 0 3.19 1895-02-01 39 21 30.0 -3.7 35 0 0.00 0.0 1895-02-02 31 16 23.5 -10.3 41 0 0.16 4.0 1895-02-03 31 12 21.5 -12.4 43 0 0.00 0.0 1895-02-04 30 11 20.5 -13.5 44 0 0.00 0.0 1895-02-05 11 0 5.5 -28.7 59 0 0.00 0.0 1895-02-06 10 -4 3.0 -31.3 62 0 0.00 0.0 1895-02-07 13 6 9.5 -24.9 55 0 0.17 S 1895-02-08 8 2 5.0 -29.6 60 0 0.13 5.0A 1895-02-09 19 4 11.5 -23.3 53 0 0.00 0.0 1895-02-10 24 18 21.0 -13.9 44 0 0.00 0.0 1895-02-11 30 17 23.5 -11.6 41 0 0.00 0.0 1895-02-12 34 18 26.0 -9.3 39 0 0.00 0.0 1895-02-13 27 21 24.0 -11.4 41 0 T T 1895-02-14 31 21 26.0 -9.6 39 0 0.00 0.0 1895-02-15 35 22 28.5 -7.3 36 0 0.00 0.0 1895-02-16 33 21 27.0 -9.0 38 0 0.00 0.0 1895-02-17 40 26 33.0 -3.2 32 0 0.00 0.0 1895-02-18 42 26 34.0 -2.4 31 0 0.00 0.0 1895-02-19 43 30 36.5 -0.1 28 0 0.00 0.0 1895-02-20 34 25 29.5 -7.3 35 0 0.00 0.0 1895-02-21 43 30 36.5 -0.5 28 0 0.00 0.0 1895-02-22 33 18 25.5 -11.7 39 0 T T 1895-02-23 29 16 22.5 -14.9 42 0 0.00 0.0 1895-02-24 30 15 22.5 -15.1 42 0 0.00 0.0 1895-02-25 41 26 33.5 -4.4 31 0 0.00 0.0 1895-02-26 34 19 26.5 -11.6 38 0 0.00 0.0 1895-02-27 44 20 32.0 -6.3 33 0 0.00 0.0 1895-02-28 46 38 42.0 3.5 23 0 0.00 0.0

https://berkeleyearth.org/global-temperature-report-for-2024/ However, the warming spike in 2023/2024 appears to have deviated significantly from the previous trend. If we were to assume that global warming was continuing at the same rate as during the 50-year period 1970-2019, then the 2023/2024 excursion would be by far the largest deviation from that trend, with only a roughly 1-in-100 chance of occurring solely due to natural variability. While 1-in-100 chance events do sometimes occur, we consider it more likely that the recent rate of global warming has been larger than expected, exceeding both the previous trend and what would be expected when considering only the observed pattern of greenhouse gas emissions.

Yeah, it’s the same theme this month that we saw with the record cold going to our south and west back in February 2021. Notice the warmer departures in Maine also. Very difficult for cold to be focused over the Northeast these days. The last time the core of a record cold airmass was focused over the Northeast for a month was way back in February 2015.

The Southeast Ridge should be a bigger player in February than January so we should lose the suppression pattern of this month.

The sensible weather here since October hasn’t been matching up with the MJO expectations for the past similar phases and corresponding 500mb patterns.

To me any low below 32° in the winter is cold since you need a jacket and sweatshirt. But I was referencing the earlier Euro forecasts which were too cold by nearly 10°. Like the EPS forecast you mentioned of the high not getting above 32° in NYC from the 6th to 16th. Lows in the 10-12° range in January for NYC aren’t considered that anomalous compared to what we used to get in the past. What is unusual is the snowfall so far this month in NYC. We are on track for the lowest January snowfall for a NYC monthly average temperature of around 30.0° and colder. I know people keep saying cold and dry like the 70s and 80s. But NYC usually got much better snows even back then when January would have average monthly temperatures near this temperature range. 2025…31.8°…..3.0”….so far 2022…30.3°….15.3” 2018….31.7°….11.2” 2015…29.9°….16.9” 2014…28.6°….19.7” 2011….29.7°….36.0” 2009..29.7°….9.0” 1996..30.5°…26.1” 1994…25.5°..12.0” 1988….29.5°…13.9” 1985….28.8°….8.4” 1984…29.9°….11.7” 1982…26.1°…..11.8” 1981…26.2°….8.0” 1978…28.0°….20.3” 1977….22.0°….13.0” 1976….27.3°….5.6” 1971…..26.9°….11.4”

That’s a very good question. All we know is that NYC frequently got to the middle 19” to 29” snowfall range with or without KU snowstorms in the 1970s and 1980s. So in the much colder climate a KU wasn’t a prerequisite to get near to over 20” like it has become since the 1990s. 87-88….19.1”….No KU 86-87…..23.1”…KU 84-85….24.1”…No KU 83-84….25.4”…No KU 82-83….27.2”….KU 81-82….24.6”…KU 78-79….29.4”….KU 76-77….24.5”….No KU 73-74…..23.5”…No KU 71-72…..22.9…..No KU

That was due to the great radiational cooling and snow cover closer to your area. Since many spots from NYC to the immediate shoreline need the winds to stay up for their coldest readings when the flow is N to NW down the Hudson Valley and not the W. The Euro originally was too suppressed and didn’t have the heavier snows near your area. It also was initially too cold for the coast and missed the rain and 40° warmth before the changeover on Sunday. Which combined with the subsidence and weaker precip rates for lower totals near the coast.

As expected the Euro was nearly 10° too cold in spots around NYC and the coast with the westerly flow crossing the warm Great Lakes region. Current low so far of 12° in NYC. So NYC and coastal sections wont be as cold as we were in early February 2023 on the N to NW flow when NYC got to 3° with subzero lows across the CT Shoreline.

My guess is that the variables have increased since 18-19 due to these expanding record marine heatwaves in basins like the Pacific. So the Northern stream of the Pacific Jet wasn’t able to relax this winter to date compared other La Ninas with +PNAs and -AOs. Plus the magnitude and location actual 500 mb anomalies has shifted relative to past +PNA and -AO La Nina episodes. So patterns in the recent 30 year past that were favorable for heavy snows and become less so recently. Something similar happened with the near record -AO during December 2022. Past La Ninas in this range produced record snowstorms like in the Boxing Day blizzard in 2010. But we got through that pattern with very little snowfall to show for it. So changing jet dynamics and storm tracks have added a new layer to our understanding of what 500mb longwave patterns will produce for us now. We have to do the best we can with the data that is available. Since climate shifts are usually are rear view mirror assessments that we only notice once we are already into a new regime. It’s uncertain how much longer this faster Pacific Jet pattern will continue with cutters, huggers, and suppressed southern stream storm tracks.