bluewave

https://www.nature.com/articles/s41558-023-01801-6 Understanding the recent increase in multiyear La Niñas Abstract Five out of six La Niña events since 1998 have lasted two to three years. Why so many long-lasting multiyear La Niña events have emerged recently and whether they will become more common remains unknown. Here we show that ten multiyear La Niña events over the past century had an accelerated trend, with eight of these occurring after 1970. The two types of multiyear La Niña events over this time period followed either a super El Niño or a central Pacific El Niño. We find that multiyear La Niña events differ from single-year La Niñas by a prominent onset rate, which is rooted in the western Pacific warming-enhanced zonal advective feedback for the central Pacific multiyear La Niña events type and thermocline feedback for the super El Niño multiyear La Niña events type. The results from large ensemble climate simulations support the observed multiyear La Niña events–western Pacific warming link. More multiyear La Niña events will exacerbate adverse socioeconomic impacts if the western Pacific continues to warm relative to the central

That the power of even a little forcing near MJO 4-6 around 120 E to pump the Southeast ridge. New run Old run

Looks like NYC continues to miss the freezes with the weak CAA and light winds. Thanksgiving should be a nice day for travel with seasonable temperatures. Good that the rain is coming in ahead of the holiday and after.

It’s pretty rare that we get any decent frozen precip events along the coast in late November with a piece of the trough hanging back over the SW.

So we get a battle between the Nino-like +PNA -EPO and Niña-like Southeast ridge around Thanksgiving.

You can already see the forcing back and forth this month.

It’s really a +30C forcing battle between the Maritime Continent and the area around the Dateline as the IOD is rapidly fading with big SST increases in MJO 4-6.

Yeah, much better pattern on Long Island than points further west.

That was still one of my favorite snowfall seasons. Probably the greatest Euro control run in history. The 950 mb benchmark blizzard could be the last time one of these Lockitin posts actually verified. https://www.weather.gov/okx/Blizzard_Jan42018

The 17-18 winter was +1.1 warmer than average due to the record 80° warmth in February. So the cold departures from December into January got erased by the big +6.1 departure in February. NYC Feb 23…+5.2 Jan 23…+9.8 Dec 22…-0.6 …………..+4.8 Feb 22….+1.4 Jan 22….-3.2 Dec 21….+4.7 ……………..+1.0 Feb 21….-1.7 Jan 21….+1.1 Dec 20…+1.7 …………..+0.4 Feb 20…+4.8 Jan 20….+6.5 Dec 19….+0.8 …………….+4.0 Feb 19….+0.9 Jan 19….-0.1 Dec 18…+2.6 …………….+1.1 Feb 18…+6.7 Jan 18….-0.9 Dec 17…..-2.5 …………….+1.1 Feb 17…..+6.3 Jan 17….+5.4 Dec 16….+0.8 …………….+4.2 Feb 16….+2.4 Jan 16….+1.9 Dec 15….+13.3 …………….+5.9

We have had snow droughts before, but never an 8 winter cold drought before.

Yeah, the most impressive Arctic outbreak since 15-16 went to our west in February 2021. The February departures weren’t low enough for the winter to average colder than normal. So we go into this winter with a record 8 warmer than average winters in a row. A record breaking 8 warmer than normal winters in a row since the 15-16 super El Niño. NYC Feb 23…+5.2 Jan 23…+9.8 Dec 22…-0.6 …………..+4.8 Feb 22….+1.4 Jan 22….-3.2 Dec 21….+4.7 ……………..+1.0 Feb 21….-1.7 Jan 21….+1.1 Dec 20…+1.7 …………..+0.4 Feb 20…+4.8 Jan 20….+6.5 Dec 19….+0.8 …………….+4.0 Feb 19….+0.9 Jan 19….-0.1 Dec 18…+2.6 …………….+1.1 Feb 18…+6.7 Jan 18….-0.9 Dec 17…..-2.5 …………….+1.1 Feb 17…..+6.3 Jan 17….+5.4 Dec 16….+0.8 …………….+4.2 Feb 16….+2.4 Jan 16….+1.9 Dec 15….+13.3 …………….+5.9

That’s preventing Nino 3.4 from going super on ONI with warmth too far in the east and near the Dateline. So it leaves the subsurface under 3.4 cooler than usual for an El Niño.

Yeah, not sure what it’s going to take to finally see a cold winter again in the Northeast. Northeast DJF average temperatures since 15-16 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

Ensembles backing off on cold around Thanksgiving with a warm up right after. So similar pattern of recent years with models underestimating the Southeast ridge day 6-10. New run Old run

Very warm Niña-like fall temperature pattern across North America like the last two years with not much cold air to be found.

3rd greatest 5 hour temperarure rise in November.

It’s mostly that the days have been off beyond a week which is par for the course. Instead of the warmth for Thanksgiving, it just got moved up a day. Then probably another warm up after the Thanksgiving cooldown. But the exact dates after to be determined. The last time we had a really cold Thanksgiving was back in 2018. But this year will be much warmer than that. https://www.washingtonpost.com/weather/2018/11/23/northeast-endured-its-most-frigid-thanksgiving-decades-record-cold-persists-black-friday/ Data for November 22, 2018 through November 22, 2018 Click column heading to sort ascending, click again to sort descending. State Name Station Type Lowest Min Temperature CT MERIDEN MARKHAM MUNICIPAL AP WBAN 10 NY MONTGOMERY ORANGE COUNTY AP WBAN 12 NY CARMEL 4N COOP 12 NY PORT JERVIS COOP 13 CT DANBURY MUNICIPAL AP WBAN 13 CT DANBURY COOP 13 NY WESTCHESTER CO AP WBAN 14 NJ CHARLOTTEBURG RESERVOIR COOP 14 CT MOUNT CARMEL COOP 14 NJ CALDWELL ESSEX COUNTY AP WBAN 15 NY SHRUB OAK COOP 15 NY WEST POINT COOP 15 CT GROTON NEW LONDON AP WBAN 15 CT GROTON COOP 15 CT IGOR I SIKORSKY MEMORIAL AIRPORT WBAN 16 NY MATTITUCK COOP 16 CT NORWICH PUBLIC UTILITY PLANT COOP 16 NJ NEWARK LIBERTY INTL AP WBAN 17 NY NY CITY CENTRAL PARK WBAN 17 NJ TETERBORO AIRPORT WBAN 17 NY FARMINGDALE REPUBLIC AP WBAN 17 CT STAMFORD 5 N COOP 17 NY SHIRLEY BROOKHAVEN AIRPORT WBAN 17 NY ORIENT POINT STATE PARK COOP 17 NJ HARRISON COOP 18 NY JFK INTERNATIONAL AIRPORT WBAN 18 NY ISLIP-LI MACARTHUR AP WBAN 18 NY WESTHAMPTON GABRESKI AP WBAN 18 NY BAITING HOLLOW COOP 18 NJ CANOE BROOK COOP 19 NY LAGUARDIA AIRPORT WBAN 19 NY CENTERPORT COOP 19 NY RIVERHEAD RESEARCH FARM COOP 19 NY UPTON COOP - NWSFO NEW YORK COOP 19 NY MONTAUK AIRPORT WBAN 19 NY BRIDGEHAMPTON COOP 19 NY MOUNT SINAI COOP 20 NY MOLLOY CERCOM COOP 22

OP models coming around to the idea of a warm up right after Thanksgiving as the Southeast ridge flexes. But there is still a lot of spread in the ensembles. With the convection returning near the Maritime Continent, it’s possible that the coldest departures stay to our west again.

It’s more the nature of the colder air masses this fall so far. Fronts come through and winds drop off pretty quickly. There hasn’t been any strong cold air advection behind the fronts. But this isn’t that unusual as the average first freeze in NYC last decade is 11-16. 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

It would be funny if NYC misses a freeze again for Thanksgiving. Some models drop the winds pretty quickly behind the front with very weak CAA. But Wednesday looks like the milder day ahead of the front.

Heavy rains return to Australia as the IOD rapidly fades and SSTs rebound near the Maritime Continent. This is why the longer range guidance is showing more MJO activity in that region. The 30C warm pool north of Australia is almost as big as near the Dateline. So we’ll have to watch for a forcing back and forth between those regions.

The March 99 heavy wet snow event was probably the best one in that disappointing stretch. Probably one of the lowest snow ratios we ever got in Long Beach. There was so much water content in that snow that the snapping sycamore branches sounded like gunshots in Long Beach. Data for March 14, 1999 through March 15, 1999 Click column heading to sort ascending, click again to sort descending. State Name Station Type Total Snowfall NY YORKTOWN HEIGHTS 1W COOP 9.5 CT DANBURY COOP 9.2 NJ CHARLOTTEBURG RESERVOIR COOP 9.0 NY BRIDGEHAMPTON COOP 9.0 CT NORWICH PUBLIC UTILITY PLANT COOP 8.8 CT IGOR I SIKORSKY MEMORIAL AIRPORT WBAN 8.3 CT COCKAPONSET RANGER STA COOP 8.0 NY RIVERHEAD RESEARCH FARM COOP 8.0 NY ISLIP-LI MACARTHUR AP WBAN 7.9 CT GROTON COOP 7.0 NY MINEOLA 1 NE COOP 6.1 NJ ESSEX FELLS SERVICE BLDG COOP 6.0 NY WALDEN 1 ESE COOP 6.0 NY OCEANSIDE COOP 5.8

The post you quoted from me was referring to February 83 which was our heaviest 80s snowstorm. Yeah, that was the heaviest single snowstorm of the 1980s. I can remember looking out the window of the LB High school just after noon and wondering why it was taking so long to start. But when I looked out a few minutes later it went from nothing to very heavy snow in about 10 minutes. It wasn’t until January 1996 that we had a snowstorm that was able to surpass it.

Yeah, that was the heaviest single snowstorm of the 1980s. I can remember looking out the window of the LB High school just after noon and wondering why it was taking so long to start. But when I looked out a few minutes later it went from nothing to very heavy snow in about 10 minutes. It wasn’t until January 1996 that we had a snowstorm that was able to surpass it.