bluewave

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.”

Not thinking this WWB is going to move the needle much toward super El Niño status since it was much weaker than the ones during this time of year back in 2015, 1997, and 1982.

These are the first freeze dates across the entire area for the last 10 years so nobody gets left out. 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. Year Last Value First Value Season Length Minimum 03-01 (2020) 10-31 (2020) 215 Mean 03-29 11-16 232 Maximum 04-16 (2014) 12-09 (2016) 243 2022 03-30 (2022) 29 11-19 (2022) 31 233 2021 04-03 (2021) 32 11-23 (2021) 32 233 2020 03-01 (2020) 25 10-31 (2020) 32 243 2019 03-18 (2019) 32 11-08 (2019) 29 234 2018 04-09 (2018) 32 11-14 (2018) 32 218 2017 03-23 (2017) 23 11-10 (2017) 25 231 2016 04-10 (2016) 31 12-09 (2016) 29 242 2015 04-01 (2015) 32 11-24 (2015) 32 236 2014 04-16 (2014) 31 11-18 (2014) 24 215 2013 03-23 (2013) 32 11-12 (2013) 31 233 Frost/Freeze Summary for NEWARK LIBERTY INTL AP, NJ 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 03-24 (2017) 10-19 (2015) 196 Mean 04-05 11-09 218 Maximum 04-17 (2020) 11-28 (2016) 234 2022 03-30 (2022) 29 11-18 (2022) 32 232 2021 04-03 (2021) 30 11-24 (2021) 32 234 2020 04-17 (2020) 32 10-31 (2020) 32 196 2019 04-01 (2019) 32 11-08 (2019) 29 220 2018 04-11 (2018) 32 11-10 (2018) 32 212 2017 03-24 (2017) 31 11-10 (2017) 25 230 2016 04-10 (2016) 31 11-28 (2016) 32 231 2015 03-29 (2015) 25 10-19 (2015) 31 203 2014 04-16 (2014) 31 11-08 (2014) 32 205 2013 04-04 (2013) 31 11-04 (2013) 32 213 Frost/Freeze Summary for New Brunswick Area, NJ (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 04-02 (2019) 10-18 (2015) 173 Mean 04-16 10-27 194 Maximum 05-10 (2020) 11-11 (2017) 215 2022 04-18 (2022) 29 10-30 (2022) 30 194 2021 04-03 (2021) 28 11-04 (2021) 29 214 2020 05-10 (2020) 31 10-31 (2020) 28 173 2019 04-02 (2019) 27 11-02 (2019) 30 213 2018 04-11 (2018) 26 10-19 (2018) 32 190 2017 04-09 (2017) 31 11-11 (2017) 20 215 2016 04-10 (2016) 29 10-26 (2016) 30 198 2015 04-25 (2015) 30 10-18 (2015) 28 175 2014 04-21 (2014) 30 10-20 (2014) 31 181 2013 04-22 (2013) 32 10-25 (2013) 30 185 Frost/Freeze Summary for SUSSEX AIRPORT, NJ 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 04-17 (2016) 09-21 (2020) 122 Mean 05-01 10-14 164 Maximum 05-21 (2020) 11-03 (2021) 192 2022 05-01 (2022) 32 10-09 (2022) 31 160 2021 04-24 (2021) 31 11-03 (2021) 29 192 2020 05-21 (2020) 32 09-21 (2020) 31 122 2019 04-29 (2019) 28 10-05 (2019) 30 158 2018 05-01 (2018) 32 10-18 (2018) 31 169 2017 05-04 (2017) 32 10-17 (2017) 30 165 2016 04-17 (2016) 31 - - - 2015 04-26 (2015) 28 10-17 (2015) 27 173 2014 04-25 (2014) 30 10-20 (2014) 32 177 2013 05-14 (2013) 29 10-21 (2013) 32 159 Frost/Freeze Summary for MONTGOMERY ORANGE COUNTY AP, 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 04-23 (2021) 10-05 (2019) 153 Mean 05-03 10-15 165 Maximum 05-21 (2020) 11-03 (2021) 193 2022 05-01 (2022) 30 10-08 (2022) 32 159 2021 04-23 (2021) 27 11-03 (2021) 27 193 2020 05-21 (2020) 31 - - - 2019 04-29 (2019) 30 10-05 (2019) 30 158 2018 04-24 (2018) 30 - - - 2017 05-11 (2017) 32 10-17 (2017) 31 158 2016 05-10 (2016) 32 10-11 (2016) 30 153 2015 04-26 (2015) 29 10-17 (2015) 29 173 2014 04-28 (2014) 31 10-12 (2014) 32 166 2013 05-14 (2013) 31 10-23 (2013) 30 161 Frost/Freeze Summary for WESTCHESTER CO AP, 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 03-30 (2017) 10-18 (2015) 173 Mean 04-16 11-03 200 Maximum 05-09 (2020) 11-14 (2022) 2022 04-18 (2022) 32 11-14 (2022) 30 209 2021 04-03 (2021) 28 11-04 (2021) 32 214 2020 05-09 (2020) 32 10-30 (2020) 32 173 2019 04-29 (2019) 32 11-02 (2019) 32 186 2018 04-11 (2018) 28 10-26 (2018) 32 197 2017 03-30 (2017) 29 11-10 (2017) 23 224 2016 04-13 (2016) 31 11-12 (2016) 31 212 2015 04-12 (2015) 32 10-18 (2015) 29 188 2014 04-18 (2014) 31 11-08 (2014) 30 203 2013 04-21 (2013) 32 11-04 (2013) 28 196 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 Maximum 04-16 (2014) 01-04 (2016) 281 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 JFK INTERNATIONAL 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 03-16 (2020) 10-31 (2020) 212 Mean 04-02 11-16 227 Maximum 04-16 (2014) 12-09 (2016) 242 2022 03-30 (2022) 27 11-19 (2022) 32 233 2021 04-03 (2021) 31 11-23 (2021) 32 233 2020 03-16 (2020) 32 10-31 (2020) 32 228 2019 04-02 (2019) 31 11-08 (2019) 29 219 2018 04-11 (2018) 31 11-12 (2018) 30 214 2017 03-24 (2017) 32 11-10 (2017) 25 230 2016 04-10 (2016) 31 12-09 (2016) 31 242 2015 03-29 (2015) 27 11-24 (2015) 31 239 2014 04-16 (2014) 32 11-15 (2014) 30 212 2013 04-04 (2013) 32 11-12 (2013) 32 221 Frost/Freeze Summary for FARMINGDALE REPUBLIC AP, 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 03-16 (2020) 10-26 (2013) 204 Mean 04-02 11-11 222 Maximum 04-18 (2014) 11-23 (2015) 234 2022 03-30 (2022) 28 11-15 (2022) 32 229 2021 04-03 (2021) 30 11-17 (2021) 31 227 2020 03-16 (2020) 32 10-31 (2020) 32 228 2019 04-02 (2019) 27 11-08 (2019) 29 219 2018 04-11 (2018) 30 11-11 (2018) 32 213 2017 03-24 (2017) 27 11-10 (2017) 26 230 2016 04-10 (2016) 32 11-21 (2016) 32 224 2015 04-02 (2015) 29 11-23 (2015) 32 234 2014 04-18 (2014) 32 11-15 (2014) 29 210 2013 04-04 (2013) 29 10-26 (2013) 31 204 Frost/Freeze Summary for ISLIP-LI MACARTHUR AP, 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 03-30 (2022) 10-19 (2015) 176 Mean 04-09 11-03 207 Maximum 04-25 (2015) 11-15 (2022) 229 2022 03-30 (2022) 25 11-15 (2022) 29 229 2021 04-04 (2021) 32 11-06 (2021) 31 215 2020 04-19 (2020) 31 10-31 (2020) 29 194 2019 04-02 (2019) 26 11-04 (2019) 32 215 2018 04-11 (2018) 26 10-22 (2018) 32 193 2017 03-30 (2017) 32 11-10 (2017) 26 224 2016 04-10 (2016) 32 11-14 (2016) 32 217 2015 04-25 (2015) 32 10-19 (2015) 29 176 2014 04-16 (2014) 32 11-08 (2014) 31 205 2013 04-07 (2013) 31 10-26 (2013) 32 201 Frost/Freeze Summary for IGOR I SIKORSKY MEMORIAL AIRPORT, CT 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 03-24 (2017) 10-19 (2015) 189 Mean 04-06 11-06 213 Maximum 04-23 (2020) 11-17 (2021) 230 2022 03-30 (2022) 27 11-15 (2022) 31 229 2021 04-03 (2021) 28 11-17 (2021) 29 227 2020 04-23 (2020) 32 10-30 (2020) 32 189 2019 04-02 (2019) 29 11-08 (2019) 29 219 2018 04-11 (2018) 26 11-12 (2018) 30 214 2017 03-24 (2017) 29 11-10 (2017) 24 230 2016 04-13 (2016) 31 11-01 (2016) 32 201 2015 04-02 (2015) 29 10-19 (2015) 30 199 2014 04-16 (2014) 31 11-08 (2014) 31 205 2013 04-04 (2013) 29 11-04 (2013) 32 213 Frost/Freeze Summary for NEW HAVEN TWEED AP, CT 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 04-02 (2019) 10-18 (2015) 187 Mean 04-11 11-01 204 Maximum 04-25 (2020) 11-15 (2014) 222 2022 04-05 (2022) 31 11-14 (2022) 29 222 2021 04-04 (2021) 29 11-06 (2021) 31 215 2020 04-25 (2020) 32 10-30 (2020) 30 187 2019 04-02 (2019) 24 11-04 (2019) 32 215 2018 04-12 (2018) 30 10-19 (2018) 31 189 2017 04-09 (2017) 29 11-09 (2017) 30 213 2016 04-13 (2016) 30 11-01 (2016) 31 201 2015 04-13 (2015) 31 10-18 (2015) 29 187 2014 04-21 (2014) 30 11-15 (2014) 25 207 2013 04-07 (2013) 30 10-25 (2013) 31 200

Yeah, the better radiational cooling at night makes it cooler here relative to my old place back on Long Island. But it still has been the 4th warmest October to date. I guess the good news is that even averaging around 60° for October, it will still give you colder feeling mornings. Time Series Summary for NEW HAVEN TWEED AP, CT Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Oct 1 to Oct 23 Missing Count 1 2021-10-23 63.0 0 2 2007-10-23 62.8 0 3 2017-10-23 61.9 0 4 2023-10-23 60.4 0 5 2020-10-23 60.0 0 - 1949-10-23 60.0 0

I am very close to New Haven Tweed airport. So my thermometer reads very close to what the ASOS shows. The airport is actually in a lower dip from some small hills to the west. So I made it down to 41° while HVN was 40°. Not bad for a home set up vs expensive ASOS. It’s interesting how quickly the temperatures drop here once the sun goes down especially on good radiational cooling nights. I like to use the Bishops Orchard Wunderground site in Guilford for readings that are a little more inland from me. They were 38° this morning. They also make the best apple pies I have ever had if you are in the area.

I wanted to include the historic SSTs east of Japan since the subtropical Pacific during the summer can have a large influence on the circulation patterns across the entire basin. So to encompass the entirety of the Western Pacific, I created a custom SST index from the equator to 40N. This tied in the important section east of Japan which helped to drive the deep -PDO circulation and worked in opposition to the developing El Niño in August and September. Wider Western Pacific basin SSTs north of Equator in Northern Hemispheric summer during developing El Niño years https://psl.noaa.gov/cgi-bin/data/timeseries/timeseries.pl?ntype=1&var=SST&level=2000&lat1=40&lat2=0&lon1=110&lon2=180&iseas=1&mon1=7&mon2=8&iarea=0&typeout=1&Submit=Create+Timeseries 2023…27.81 2015….27.38 2014….27.64 2009….27.44 2006….27.41 2004….27.24 2002….27.25 1997…..27.00 1994….27.37 1991…..27.20

Yeah, I finally moved outside the heat island influence and dropped to 41° for my coldest of the season so far.

Big temperature swings coming up. Near record 80° heat by the weekend. Then colder weather to start November with the first mid 30s of season in NYC. But the average lows are in the low 40s by that time so not too cold by historical standards. It will feel colder though compared to 80°.

The Western Pacific was the warmest on record for a developing El Niño in August and September. This resulted in lower pressures than usual. The lack of a strong pressure gradient between east and west resulted in some of the weakest WWBs for a developing El Niño. So the record WPAC warm pool was still in a more Nina-like mode. It makes sense that the MEI was much lower than the ONI.

I rode my bike on the LB boardwalk during the 100° and 75° dew point in July 1999. While I was much younger back then, I still got the pins and needles sensation from that 113 heat index. I actually enjoyed the 0° and 50 mph gusts on the boardwalk better in January 1985.Probably the best display of Arctic seasmoke I ever saw back in Long Beach with embedded steamnadoes. The beauty of the Long Beach boardwalk is that there is always somebody up there no matter how extreme the weather. There were people on the boardwalk 5 minutes before sections collapsed during Sandy. The Long Beach crew were some of the most adventurous people that I ever met.

Even though our rate of summer warming has been slower than the fall and winter, it still has come with a steep increase in the dew points. We are just lucky we haven’t had a summer version yet of December 2015. I believe we would need an extreme drought here to ever have a summer month approach +10. Portions of the Southern Plains approached +10 in July 2011.