bluewave

The 15-16 winter was the real outlier for Decembers with a T or less of snow in NYC since 1950. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Dec Click column heading to sort ascending, click again to sort descending. Rank Year Total Snowfall Seasonal Snowfall 2011 0.0 7.4 - 2006 0.0 12.4 2023 T 2.3…so far - 2022 T 2.3 - 2018 T 20.5 - 2015 T 32.8 - 2001 T 3.5 - 1999 T 16.3 - 1997 T 5.5 - 1996 T 10.0 - 1994 T 11.8 - 1972 T 2.8 - 1971 T 22.9 - 1965 T 21.4 - 1953 T 15.8

We haven’t had a warm and dry winter since 2001-2002. All our warm winters since then have been wet with either snow or rain. Probably the most winter bike rides that I ever got in on the Long Beach boardwalk. Time Series Summary for NY CITY CENTRAL PARK, NY - Dec through Feb Click column heading to sort ascending, click again to sort descending. Rank Season Total Precipitation Missing Count 1 1900-1901 4.22 0 2 2001-2002 4.88 0 3 1958-1959 5.28 0 4 1871-1872 5.41 0 5 1979-1980 5.45 0 6 1955-1956 5.97 0 7 1943-1944 6.13 0 8 1876-1877 6.40 0 9 1988-1989 6.45 0 10 1946-1947 6.59 0 Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Season Mean Avg Temperature Missing Count 1 2001-2002 41.5 0 2 2022-2023 41.0 0 - 2015-2016 41.0 0 3 2011-2012 40.5 0 4 1931-1932 40.1 0 5 1997-1998 39.6 0 6 2016-2017 39.3 0 7 2019-2020 39.2 0 8 1990-1991 39.1 0 9 1998-1999 38.6 0 10 1948-1949 38.5 0

Our only spring record snowfall in the 2020s so far happened in May.

We did much better in March during the 2010s than the 2020s so far. Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Mar Season Mean 0.1 0.1 2023 0.1 0.1 2022 0.4 0.4 2021 T T 2020 T T Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Mar Season Mean 6.0 6.0 2019 10.4 10.4 2018 11.6 11.6 2017 9.7 9.7 2016 0.9 0.9 2015 18.6 18.6 2014 0.1 0.1 2013 7.3 7.3 2012 0.0 0.0 2011 1.0 1.0 2010 T T

Only the 3rd time on record that northern suburbs like HPN haven’t dropped below 15° by 1-30. Time Series Summary for WESTCHESTER CO AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Lowest Min Temperature Oct 1 to Jan 30 Missing Count 1 2002-01-30 16 0 2 2024-01-30 15 1 - 1950-01-30 15 61 3 2020-01-30 13 2

The 500 mb pattern was closer to La Niña with a deep trough out West and a Southeast ridge. But the raging STJ with all the precipitation was classic El Niño. So a bit of a combination pattern as a function of the much further than west forcing for an El Niño in January.

I was talking about longer range and not inside day 7.

Just look at how much the Euro monthly struggled with its January forecast issued back in December. It was going with something similar to a stock El Niño 500 composite in January. But instead we got a more Niña-like 500 mb pattern with a much stronger STJ due to the continuing El Niño. But the forcing from the Eastern IO into WPAC was missed. This is a common theme of the weekly and monthly model runs since the 15-16 winter due to the rapid expansion of the WPAC warm pool. Forecast Verification

I think you continue to miss the point. Forcing west of the Dateline is a warm pattern for us here in the East. One of the biases exhibited by the models longer range is to weaken convection too quickly in this region. The forcing in the entire area around the WPAC warm pool has greatly surpassed the long range model forecast this winter and most winters since 15-16. This is a long term change which is independent of the El Niño this season. It’s the main reason why NYC is on track for a record 9 warmer than average winters in a row. Beyond the 2nd week of February, it’s still possible the convection can shift further east allowing something resembling a February El Niño pattern as we approach Presidents Day week. But we’ll have to just wait and see.

Yeah, the record +30C SSTs are holding the forcing in place longer now to the west of the Dateline. The old runs from a week ago were more favorable had the convection rapidly weakening. So it looks like the 2nd week of February will actually be warmer than the first week now. New runs stronger forcing west of the Dateline and warmer 2nd week of February Old runs weaker forcing to the west of the Dateline and colder pattern for 2nd week of February

Another winter with top 5 and top 10 warmth around the region to date.

This January is another example of how the La Niña background state of recent years can emerge even during a borderline super El Niño. It’s the result of the record IO to WPAC SSTs focusing the forcing closer to where we would expect to see during a La Niña. So we get a Southeast ridge pattern with 80° record warmth in DC. It’s an interesting combo with such a strong El Niño STJ in place.

Islip is getting very close to its cloudiest January on record using 9am observations. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=45&network=NY_ASOS&zstation=ISP&hour=9&year=2024&month=1&_r=t&dpi=100&_fmt=png

It almost happened in 2010 and 2011. But those years had droughts in the East. We have been very wet since then. So probably not possible without a drought. Remember, October 2019 had a flash drought which boosted our area to mid 90s. We have a much higher population and electric demand than areas of the US that typically experience 110°+. So they might start rolling blackouts to preserve the grid until demand drops off enough. Data for January 1, 2010 through December 31, 2011 Click column heading to sort ascending, click again to sort descending. State Name Station Type Highest Max Temperature NJ NEWARK LIBERTY INTL AP WBAN 108 NY MINEOLA COOP 108 NJ CANOE BROOK COOP 107 NJ HARRISON COOP 107 NY WANTAGH CEDAR CREEK COOP 107 NJ RINGWOOD COOP 106 NY MOLLOY CERCOM COOP 105 Data for October 1, 2019 through October 31, 2019 Click column heading to sort ascending, click again to sort descending. State Name Station Type Highest Max Temperature NJ NEWARK LIBERTY INTL AP WBAN 96 NY LAGUARDIA AIRPORT WBAN 95 NJ HARRISON COOP 95 NJ TETERBORO AIRPORT WBAN 95 NY JFK INTERNATIONAL AIRPORT WBAN 95

We are just fortunate that these monthly maximum temperature extremes since 2015 have occurred closer to the cool season. Not sure if the power grid is up to the record demand 110° during the summer would produce. That’s roughly what a February 2018 and October 2019 magnitude warmth would look like in July. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Feb Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2018 80 0 2 1949 76 0 3 2017 74 0 - 1997 74 0 - 1954 74 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Oct Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2019 96 0 2 1941 93 0 3 1949 92 0

Closer to a La Niña January 500 mb pattern for the US even though it’s a borderline super El Niño. Very impressive how the MJO really shaped this pattern due to the record SST warmth from the IO to WPAC. The Euro seasonal was going with a stock January El Niño 500 mb composite back with its December forecast.

It’s pretty ridiculous for DCA to even go above 75° in January during an El Niño which is supposed to be cooler in the Mid-Atlantic. All the previous years were La Ninas or ENSO neutral. Time Series Summary for WASHINGTON REAGAN NATIONAL AIRPORT, VA - Month of Jan Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature ONI 1 1950 79 -1.5 2 2002 77 -0.1 3 1975 76 -0.5 4 1974 75 -1.8

The Pine Barrens are one of the most densely forested areas of Long Island and the official weather BNL equipment is located in a clearing. That’s the national and global standard for official weather observing sites that measure temperature for meteorological purposes. But under canopy temperatures are mostly limited to studies about wildlife and biology. https://www.bnl.gov/weather/

It’s tough to get extended heatwaves anymore since the shade is at least 2-3° cooler at peak heating then then the sensors were out in the open before the 90s. Plus when the foliage is wet there could be even increased cooling.

Not when the the trees block the thermometer and radiation shield from direct sunlight. More rural weather stations have the thermometers in clearings not under a dense canopy of trees. The Central Park great lawn is probably at least 2-3° warmer during the warm season at peak daily heating than under a tree canopy near the castle. Under some weather conditions the difference at peak heating could be even higher than 3°. So the great lawn isn’t that different in regard to highs than EWR and LGA. But the shaded areas are at least 2-3° cooler. That’s why the old site in the park used to average more 90° days than LGA but a few less than EWR. The taller trees are also reducing the winds at the park. This is why NYC hasn’t been able to beat its all-time highest wind gust from the early 70s. Notice how the sensors are located away from obstructions like trees.

Looks like the 3rd cloudiest January on record at ISP using the 9am observation time. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=45&network=NY_ASOS&zstation=ISP&hour=9&year=2024&month=1&_r=t&dpi=100&_fmt=png

You are talking about 2 different things. Sure greening of cities is important for many different reasons. But temperatures aren’t measured directly under trees even at rural weather observing sites. Before the 1990s the weather instruments in Central Park were out in the open. Now they are under mature fully leafed out trees during the warm season. So this has created an artificial high temperature cooling. Had the site been properly maintained, it’s summer highs would be more in line with the surrounding stations like EWR and LGA which it was before the 90s.

Would be higher like several regional surrounding sites if the tree growth since the mid 90s didn’t artificially suppress the high temperatures during the warm season.

Record breaking dense fog extent across the US with this warmth encountering the snow cover in many places.