bluewave

March tied for warmest on record using the Berkeley Earth dataset continuing the streak of record warmth which began in 2023.

Most of the springs summers living back in Long Beach before I moved featured onshore flow. But occasionally we would get into W or WNW flow like 1993,1999, 2010, 2011, and 2012. Those were the occasions when we reached close to or made it to 100°. Even here along the CT Shoreline still get into an onshore flow much of the time as I only had 9 days reach 90° last summer vs 40 days in parts of NJ.

The Euro has a WSW flow on Saturday ahead of the cold front. So so Western LI north of the Southern State could approach 80°. JFK should be able to go 75°+ but not sure about 80° yet since there could be a short trajectory off the water.

The best La Niña snowfall analogs for Chicago this winter were 22-23 and 11-12. The strongest winter temperature analogs were 17-18, 18-19, and 20-21. While the Euro seasonal forecast was warmer than what actually verified for Chicago, the snowfall forecast was pretty good. It’s also funny how that joke about Tampa snowfall in the forecast wasn’t far from the mark with the record snow in New Orleans. Time Series Summary for Chicago Area, IL (ThreadEx) - Oct through Sep Click column heading to sort ascending, click again to sort descending. 1 1920-1921 9.8 0 2 1997-1998 10.4 79 3 1921-1922 11.5 0 4 1936-1937 12.0 0 5 1948-1949 14.3 0 6 2024-2025 17.6 168 7 1924-1925 18.9 0 8 1914-1915 19.0 0 - 1901-1902 19.0 0 9 1912-1913 19.1 0 10 2011-2012 19.8 0 11 1957-1958 20.0 0 12 2022-2023 20.2 0 2018-2019 26.7 0 1990-1991 26.8 0 2017-2018 26.9 0 - 1968-1969 26.9 0 - 1957-1958 26.9 0 - 1939-1940 26.9 0 1946-1947 27.0 0 1967-1968 27.1 0 - 1924-1925 27.1 0 1934-1935 27.2 0 2024-2025 27.3 0 2020-2021 27.4 0

Looks like the cutter next week won’t be as strong. So our next run on 80° this weekend won’t be followed by such strong winds. Then another chance of approaching 80° next week. So improving spring conditions going forward.

Yeah, it was the windiest winter also. While there have always been cutters, the storm track through the Great Lakes this year has been supercharged. This is how a winter with an average of 34.8° in NYC can run 41.0° on the 11 days that precipitation over .25 fell.

The biggest issue for the Philly airport is it consistently is subject to cooling breezes off the Delaware River. This makes it an unrealistic proxy for the actual warm season temperatures in downtown Philadelphia which runs several degrees warmer. So residents in the densest population zones in the Philadelphia urban centers are experiencing warmer conditions than the airport. Same goes for the airport at Newark. The ASOS is very close to the bay and experiences cooling sea breezes which keep the temperatures lower than the urban areas just inland from the sea breeze influence. So where the residents actually live they experience warmer conditions than the airport. NYC has a different twist to underreporting the actual urban temperatures. When the NWS left NYC in the early 1990s the Central Park observing site fell into disrepair. They installed an ASOS under a tree canopy placing it in the deep shade in 1995. The old ASOS was in an open sitting not under a cooler canopy. So this created an artificial cooling in the NYC temperature record around 1995 since the measurements before then were taken out in the open. This is why the NYC readings started running cooler than surrounding sites when it had been warmer or as warm as the surrounding sites in the years prior to the 1990s. LaGuardia airport also has issues with cooler warm season readings than the surrounding sites since the ASOS is right on the water and gets cooling breezes. So its temperatures in the warm season run cooler than the surrounding sites. The good news is that NYC established a micronet and placed sensors in the densest urban city neighborhoods where the people actually live. These readings have shown that the neighborhoods where the people actually live have consistently run warmer than the airport. There have been numerous 100° readings just inland from the airport to the south when the airport only maxed out in the 90s. So the moral of the story is that we need more thermometers in the warmer neighborhoods since they aren’t subject to the cooling breezes that the airports often get. This does a disservice to the residents in these urban environments that have to experience higher levels of heat than the cooler local airports.

The strong winds will continue to be the common denominator.

Saturday looks like or next run on 80° for the warm spots.

Good question. Today should see a drop off in the winds. But tomorrow will have very steep low level lapse rates. So we could see 45-50 mph westerly gusts especially if the downslope warming beats guidance by a few degrees like we haven been regularly experiencing.

Yeah, they made to 93° on 4-14-23 and had to wait until July 3rd to get that warm again.

Big improvement from yesterday. MAXIMUM 60 254 PM 92 2023 62 -2 MAXIMUM 43 1205 AM 90 1977 61 -18

Philly is in a much different multiyear snow drought this time around. The 7 year snowfall average dipped to 10.5” for the first time on record after 24-25 snowfall season just ended. Marking an unprecedented reversal from the 7 year record high of 36.8” in 15-16. Lowest 7 year snowfall averages in Philly 2025….10.5” 1992….14.9” 1977…..14.4” 1955….13.4” 1933….12.5”

Record breaking 61 days with wind gusts over 30 mph since January 1st. Newark/Liberty PTSUNNY 58 37 45 NW20G37 https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=140&network=NJ_ASOS&station=EWR&syear=1900&sday=0101&eday=0412&varname=avg_wind_gust&w=aoa&thres=30&year=2025&_r=t&dpi=100&_fmt=png

Looks like the Euro is capturing the warmer downslope conditions today better than some of the other guidance.

The main correlation with storm tracks since 18-19 has been the Pacific Jet. We got a relaxation during 20-21 which allowed the -NAO -AO to produce a KU BM track on 2-1-21 and another smaller BM event about a week later. Also a brief window in January 22 with the MJO 8 +PNA which favored areas from ACY to ISP to BOS. Just a little wide of the BM for areas a little further west to cash in. But most other times the Pacific Jet has had an overpowering influence leading to cutters, huggers, and suppressed Southern Stream storm tracks. Plus the stronger Southeast Ridge influence even at times of strong -NAO and -AO intervals which was absent before this decade at times of such strong blocking. So this adds a new conditionality to those older correlations. So you need to take more of bigger picture view rather than just looking at the NAO in isolation. If you noticed we finally got something close to a BM track the last few days. The reason the lagged -NAO correlation finally worked now and not over the winter was due to the Pacific Jet backing off a bit from recent months. My guess is that the record warmth in Siberia weakened the gradient between the record SST warmth east of Japan allowing the jet to back off.

Yeah. 1983-04-19 45 35 40.0 -12.1 25 0 0.87 1.5 T

It was the latest in NYC since 1980. Frost/Freeze Summary for NY CITY CENTRAL PARK, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. 1891 05-06 (1891) 32 11-04 (1891) 30 181 1874 04-30 (1874) 32 11-12 (1874) 32 195 1919 04-26 (1919) 31 11-14 (1919) 30 201 1892 04-25 (1892) 32 11-11 (1892) 32 199 1888 04-25 (1888) 31 11-17 (1888) 30 205 1930 04-24 (1930) 31 11-06 (1930) 31 195 1872 04-23 (1872) 29 11-16 (1872) 30 206 1875 04-22 (1875) 28 11-02 (1875) 31 193 1925 04-21 (1925) 32 10-29 (1925) 31 190 1922 04-21 (1922) 32 11-21 (1922) 32 213 1926 04-20 (1926) 28 11-04 (1926) 31 197 1904 04-20 (1904) 27 10-31 (1904) 32 193 1897 04-20 (1897) 24 11-18 (1897) 32 211 1890 04-19 (1890) 30 11-21 (1890) 31 215 1887 04-19 (1887) 29 10-30 (1887) 32 193 1980 04-17 (1980) 32 11-16 (1980) 32 212 2014 04-16 (2014) 31 11-18 (2014) 24 215

February 2015 was a one-off type event that we won’t see again absent some massive volcanic eruption dramatically cooling the earths climate.

April 1875 was very cold and snowy which would be a -10 by today’s much warmer climate normals. April 16th through the 22nd was close to what our average January temperstures are these days at only 34.1°. So not something we can experience anymore in the much warmer climate. Climatological Data for NY CITY CENTRAL PARK, NY - April 1875 Click column heading to sort ascending, click again to sort descending. Sum 1500 1031 - - 590 0 3.08 13.5 Average 51.7 35.6 43.7 -10.0 - - - - Normal 61.8 45.5 53.7 - 354 14 4.09 0.4 1875-04-01 61 39 50.0 1.9 15 0 0.00 0.0 1875-04-02 65 48 56.5 8.1 8 0 0.06 0.0 1875-04-03 55 41 48.0 -0.8 17 0 0.34 0.0 1875-04-04 46 37 41.5 -7.7 23 0 0.31 0.0 1875-04-05 58 37 47.5 -2.1 17 0 0.00 0.0 1875-04-06 54 M M M M M 0.00 0.0 1875-04-07 M 31 M M M M 0.06 0.5 1875-04-08 51 33 42.0 -8.8 23 0 0.00 0.0 1875-04-09 47 37 42.0 -9.2 23 0 0.02 0.0 1875-04-10 61 39 50.0 -1.6 15 0 0.00 0.0 1875-04-11 66 47 56.5 4.5 8 0 0.00 0.0 1875-04-12 48 35 41.5 -10.9 23 0 0.10 T 1875-04-13 35 30 32.5 -20.3 32 0 0.87 8.7 1875-04-14 52 30 41.0 -12.2 24 0 0.14 1.3 1875-04-15 57 41 49.0 -4.6 16 0 0.00 0.0 1875-04-16 48 33 40.5 -13.5 24 0 0.10 T 1875-04-17 33 27 30.0 -24.3 35 0 T T 1875-04-18 32 25 28.5 -26.2 36 0 T T 1875-04-19 40 22 31.0 -24.1 34 0 0.00 0.0 1875-04-20 41 29 35.0 -20.5 30 0 0.00 0.0 1875-04-21 43 26 34.5 -21.3 30 0 0.00 0.0 1875-04-22 51 28 39.5 -16.7 25 0 0.00 0.0 1875-04-23 60 35 47.5 -9.0 17 0 0.00 0.0 1875-04-24 59 35 47.0 -9.9 18 0 0.37 0.0 1875-04-25 51 34 42.5 -14.7 22 0 0.44 3.0 1875-04-26 61 41 51.0 -6.6 14 0 0.00 0.0 1875-04-27 58 45 51.5 -6.4 13 0 0.00 0.0 1875-04-28 46 42 44.0 -14.2 21 0 0.21 0.0 1875-04-29 54 40 47.0 -11.5 18 0 0.06 0.0 1875-04-30 67 44 55.5 -3.4 9 0 0.00 0.0 Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending 4-16 to 4-22 1 1875-04-22 34.1 0

It just happened a few years ago several times at even later dates. The big change we have seen is that these April snow events are struggling to accumulate near the coast as it gets warmer. So we wind up with just a trace rather than an accumulation.

This wasn’t that big of a deal. Since LGA had accumulating snow and not just a T a few days later back in 2014. Then a T on 5-9-20. Maybe if the low temperatures were really cold like the maxes were yesterday they could have had a light accumulation. 2014-04-16 47 32 39.5 -14.4 25 0 0.05 0.2 2020-05-09 49 36 42.5 -19.2 22 0 0.03 T

Correlations or associations shift over time with the climate. From the 1950s to early 1970s -PNA -NAO -AO was associated with a trough in the East. But in recent times this has featured a strong Southeast Ridge. Even the -NAOs and -AOs have been occurring with a strong Southeast Ridge. My guess as to why this has been the case is due to the rapid warming of the Atlantic Ocean leading to a stronger subtropical ridge. So when we used to get more of a trough in the East the tendency has become more of a Southeast Ridge. This is the weakness's of just relying on the older teleconnections like NAO, AO, PNA, and EPO and not recognizing changes in the ridge structures and orientations further south. Plus the much stronger Pacific Jet is playing a role in the ridge strength also.

That was in 2020 leading up to the record May snowfall. April 2002 was only a little warmer than average by modern standards. But the warmth from the 13th to 19th was very impressive. Climatological Data for NEWARK LIBERTY INTL AP, NJ - April 2002 Click column heading to sort ascending, click again to sort descending. Sum 1963 1396 - - 330 68 3.76 T - Average 65.4 46.5 56.0 2.7 - - - - 0.0 Normal 62.6 44.1 53.3 - 363 14 3.87 0.5 2002-04-01 62 45 53.5 5.7 11 0 0.07 0.0 0 2002-04-02 58 39 48.5 0.3 16 0 0.00 0.0 0 2002-04-03 77 41 59.0 10.4 6 0 0.05 0.0 0 2002-04-04 52 37 44.5 -4.4 20 0 0.00 0.0 0 2002-04-05 44 33 38.5 -10.8 26 0 T T 0 2002-04-06 49 32 40.5 -9.2 24 0 T T 0 2002-04-07 49 28 38.5 -11.6 26 0 0.00 0.0 0 2002-04-08 62 40 51.0 0.5 14 0 T 0.0 0 2002-04-09 77 55 66.0 15.1 0 1 0.07 0.0 0 2002-04-10 67 48 57.5 6.2 7 0 0.01 0.0 0 2002-04-11 57 47 52.0 0.3 13 0 0.00 0.0 0 2002-04-12 55 43 49.0 -3.1 16 0 0.06 0.0 0 2002-04-13 74 54 64.0 11.5 1 0 0.07 0.0 0 2002-04-14 74 55 64.5 11.6 0 0 0.09 0.0 0 2002-04-15 82 58 70.0 16.8 0 5 0.02 0.0 0 2002-04-16 92 64 78.0 24.4 0 13 0.00 0.0 0 2002-04-17 97 68 82.5 28.5 0 18 0.00 0.0 0 2002-04-18 93 74 83.5 29.1 0 19 0.00 0.0 0 2002-04-19 91 63 77.0 22.2 0 12 0.59 0.0 0 2002-04-20 69 54 61.5 6.4 3 0 0.23 0.0 0 2002-04-21 56 48 52.0 -3.5 13 0 0.01 0.0 0 2002-04-22 58 42 50.0 -5.9 15 0 0.29 0.0 0 2002-04-23 56 39 47.5 -8.7 17 0 0.00 0.0 0 2002-04-24 61 37 49.0 -7.6 16 0 0.00 0.0 0 2002-04-25 52 43 47.5 -9.4 17 0 0.50 0.0 0 2002-04-26 61 40 50.5 -6.8 14 0 0.00 0.0 0 2002-04-27 65 38 51.5 -6.1 13 0 0.03 0.0 0 2002-04-28 57 48 52.5 -5.5 12 0 1.54 0.0 0 2002-04-29 57 43 50.0 -8.3 15 0 T 0.0 0 2002-04-30 59 40 49.5 -9.1 15 0 0.13 0.0 0

The NAO was much more positive from 11-12 to 17-18 than it has been from 18-19 to 24-25. Yet there was a record number of BM tracks from 11-12 to 17-18 with the strong +NAO over those winters. But very few BM tracks in the last 7 seasons vs the previous 7 seasons. Which has been reflected in the steep snowfall decrease in places like NYC Metro region. So as I have said, it’s the Pacific Jet driving the decline in BM tracks and snowfall much more than the Atlantic side and teleconnections like the NAO. Trying to use correlations from a different climate era isn’t going to work out.