bluewave

We almost got it done last March but the big storm tracked about 100 miles too far north and favored the interior.

We used to do better in the old days with a trough digging into the Baja and -AO. But the tendency for more south based blocks in recent years hurt us.

Not much difference between the low of 59 at Albany and 63 at LGA.

We were talking about temperature and not snowfall. It was a record breaking 8 warmer than average winters in a row in the Northeast. Most of the winter forecasts have been biased too cold in the Northeast. So going warm regardless of ENSO or polar domain has been a winning hand. Average winter temperatures in the Northeast (DJF) https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/regional/time-series/101/tavg/3/2/1895-2023?base_prd=true&begbaseyear=1981&endbaseyear=2010 22-23…30.7….+4.9….2nd warmest 21-22….26.1…..+0.3 20-21….27.1….+2.2…16th warmest 19-20….28.9…+4.0…6th warmest 18-19….25.6….+0.7 17-18….25.3….+0.4 16-17….29.5…..+4.6..5th warmest 15-16…30.7……+5.8…2nd warmest

The models have really struggled with this La Niña background pattern.

The more aggressive models with the warming like the Euro have been running too warm since 12-13 with the persistent La Niña background state. But we have also seen the warm bias go beyond the spring into September like this year.

Overperforming warm ups have become the new normal.

The recent WWBs were too weak compared to past El Niños to move the needle much on Nino 3.4 with such low upper ocean heat content. So the October monthly average is going to come in closer to 1.6 than the Euro 2.03 super Nino forecast. ECMWF 2.03

Just made the Lockitin hall of fame.

That just goes to show how even a few degrees above normal in our warmer climate is still top 10 warmth for our area. Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Oct Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2017 61.9 0 2 2021 61.2 0 3 2007 61.1 0 4 1990 60.9 0 5 1971 59.7 0 6 2023 58.6 6 7 1995 58.5 0 8 1963 58.3 0 9 2019 57.9 0 - 2013 57.9 0 - 2012 57.9 0 10 2016 57.5 0 - 2014 57.5 0 - 1984 57.5 0 Time Series Summary for WESTCHESTER CO AP, NY - Month of Oct Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2017 61.5 0 2 1971 60.3 0 3 2007 60.1 0 4 2021 59.8 3 5 1963 58.5 0 6 1954 58.0 0 7 1995 57.9 10 8 1984 57.8 0 9 2023 57.7 6 10 1949 57.5 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 Mean Avg Temperature Missing Count 1 2021 64.4 0 2 2017 63.8 0 3 2007 63.5 0 4 1971 63.1 0 5 1990 62.4 0 6 1984 62.2 0 7 2023 61.9 6 8 1949 61.6 0 9 1963 61.2 0 10 1995 61.0 0 - 1947 61.0 0 Time Series Summary for NEW HAVEN TWEED AP, CT - Month of Oct Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2021 61.2 0 2 2017 61.1 0 3 2023 60.0 6 - 2007 60.0 0 4 2019 58.7 0 5 1949 58.1 0 6 2014 58.0 0 - 2012 58.0 2 7 1970 57.4 0 - 1954 57.4 0 8 2020 57.2 0 9 1968 57.1 0 Time Series Summary for Poughkeepsie Area, NY (ThreadEx) - Month of Oct Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2017 58.5 0 2 2021 58.2 0 3 2007 58.0 0 4 1947 57.9 0 5 1971 57.4 0 6 1931 57.3 0 7 2023 56.9 6 8 1949 56.2 0 9 1932 55.9 2 10 1963 55.8 0 - 1946 55.8 0

I would consider 09-10 a solid +PDO pattern due to the Aleutian low driven cold pool NW of Hawaii. But the official index weighs the area off the West Coast also and it still was cooler from the previous -PDO winters. But to me, the area NW of Hawaii has more influence on our 500 mb patterns. Our only below normal temperature El Niño winters in NYC with 50” of snow in the last 30 years were 14-15, 09-10, and 02-03. Those were Modoki El Niños with that cold pool Aleutian low signature NW of Hawaii.

I hear what you are saying. But even a neutral to slightly negative PDO with a wam pool and Aleutian ridge north of Hawaii is going to be warm in the winter when combined with an El Niño. An Aleutian ridge will push a trough into the SW US even with a +PNA ridge in Canada. The end result will be a downstream ridge over the Northeast. So we want a solidly positive +PDO or uncoupled -PDO.

Not much in the way of below normal this month. There was a time in the past when a deep trough near the East Coast in October was colder. So another very late first freeze for the Northeast.

Still have an extensive -PDO warm pool across 30-40 N in the NPAC. So this -PDO index rise is more noise than anything else right now. Need to see a cold pool there and persistent Aleutian Low take hold for a more +PDO-like Nino pattern.

And during the early winter this would be a marginal airmass when even a benchmark track could have mixing issues near the coast. So we would probably have to wait until further into January and February for better snow potential near the coast.

This was probably one of the strongest La Niña October temperature patterns across the CONUS during an El Niño.

Great blocking pattern this month but no cold air.

Out of all the rapid intensifications we have seen near the time landfall in recent years this was the most extreme.

It think it’s coincidental since 2 years were super El Niño’s which are warm and 3 were -PDO El Niño’s which were warm also.

Yeah, Newark radiates better being in a marshy area. Plus NW and W flow is colder than LGA since the LGA gets a warming breeze off the water with a W or NW flow in the winter. So Newark has significantly more lows of freezing or colder than LGA since the super El Niño. Monthly Number of Days Min Temperature <= 32 for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season Mean 0 5 14 23 18 12 2 74 2021-2022 0 2 6 28 23 12 0 71 2020-2021 1 2 19 25 21 12 2 82 2019-2020 0 11 19 18 13 3 1 65 2018-2019 0 9 17 25 21 16 1 89 2017-2018 0 8 21 24 13 18 4 88 2016-2017 0 1 18 13 18 16 0 66 2015-2016 1 4 0 27 17 6 5 60 Monthly Number of Days Min Temperature <= 32 for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season Mean 0 2 9 18 14 8 1 52 2021-2022 0 0 4 26 19 11 0 60 2020-2021 0 0 12 13 17 10 1 53 2019-2020 0 8 13 12 11 1 0 45 2018-2019 0 5 11 23 18 9 0 66 2017-2018 0 2 14 22 10 7 1 56 2016-2017 0 0 8 10 9 14 0 41 2015-2016 0 0 0 20 14 4 3 41

The PDO is usually the deciding factor if the MEI is weak during the winter months. This was the case in 94-95 and 04-05. The 94-95 MEI peaked early in October at +1.5 but weakened to +0.5 during the winter. 04-05 had similar winter values +0.6 to +0.8. So the -PDO was the deciding factor which lead to the very warm winter for the CONUS. https://psl.noaa.gov/enso/mei/ https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat Winter MEI <1 and -PDO

Yeah, the first freeze at RDU comes earlier than LGA. The first freeze date at TLH and LGA are actually similar. 15-16 was the latest first freeze at LGA coming on January 4th. So it’s probably safe to say LGA is the UHI capitol of the Eastern US. Frost/Freeze Summary for RALEIGH-DURHAM INTERNATIONAL AIRPORT, NC Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Season Length Minimum 03-23 (2017) 10-19 (2015) 199 Mean 04-06 11-07 215 2022 03-29 (2022) 30 11-14 (2022) 31 229 2021 04-23 (2021) 31 11-14 (2021) 29 204 2020 04-11 (2020) 32 11-18 (2020) 31 220 2019 04-03 (2019) 31 11-09 (2019) 27 219 2018 04-08 (2018) 32 11-11 (2018) 28 216 2017 03-23 (2017) 31 11-11 (2017) 28 232 2016 04-10 (2016) 29 11-12 (2016) 30 215 2015 03-29 (2015) 22 10-19 (2015) 32 203 2014 04-17 (2014) 31 11-03 (2014) 29 199 2013 03-29 (2013) 28 10-26 (2013) 29 210 Frost/Freeze Summary for LAGUARDIA AIRPORT, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Season Length Minimum 03-01 (2020) 11-08 (2019) 215 Mean 03-27 11-27 245 2022 03-30 (2022) 30 11-19 (2022) 32 233 2021 04-02 (2021) 29 12-19 (2021) 31 260 2020 03-01 (2020) 26 12-08 (2020) 32 281 2019 03-13 (2019) 32 11-08 (2019) 31 239 2018 04-02 (2018) 32 11-15 (2018) 30 226 2017 03-23 (2017) 26 11-10 (2017) 27 231 2016 04-06 (2016) 32 12-09 (2016) 32 246 2015 03-29 (2015) 27 01-04 (2016) 15 280 2014 04-16 (2014) 32 11-18 (2014) 24 215 2013 03-22 (2013) 30 11-12 (2013) 32 234 Frost/Freeze Summary for Tallahassee Area, FL (ThreadEx) Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Season Length Minimum 02-20 (2015) 10-20 (2022) 220 Mean 03-08 11-24 261 2022 03-13 (2022) 32 10-20 (2022) 31 220 2021 03-09 (2021) 32 11-23 (2021) 32 258 2020 02-28 (2020) 29 12-01 (2020) 30 276 2019 03-07 (2019) 31 12-03 (2019) 29 270 2018 03-15 (2018) 27 11-28 (2018) 29 257 2017 03-16 (2017) 27 12-09 (2017) 29 267 2016 02-28 (2016) 32 11-21 (2016) 30 266 2015 02-20 (2015) 22 12-20 (2015) 31 302 2014 02-28 (2014) 27 11-03 (2014) 30 247 2013 03-28 (2013) 32 11-28 (2013) 30 244

Could be since we just go our first daily decline in months. So we’ll have to monitor to see if the models starting moving to some MJO 4-6 intervals in coming months. The MJO 4-6 returned in December 2019 when the daily values got under +1. So the it’s not necessary for the IOD go completely neutral before convection and forcing returns to the Maritime Continent.

I am guessing the freeze will be limited to areas outside the heat island since the average first freeze date in NYC last 10 years has been 11-16.

Luckily, it’s just the AMOC and not the Gulf Stream that is slowing down. While we would still see steady warming here, there would be no big cooldown outside the small area south of Greenland. https://bigthink.com/strange-maps/gulf-stream-collapse-amoc/ There is evidence that [the AMOC] has slowed down, and even collapsed, in the past… If the AMOC collapses — but there is no direct evidence of this — it would be a serious issue for the region [of the Greenland and Norwegian Seas]. It would probably introduce some cooling to a region that otherwise would be warming now… But the larger Gulf Stream circulation would continue operating, largely as before.”