bluewave

The mid-February period was nothing resembling a +NAO Arctic blocking pattern. There was a -5SD block over the pole which extended all the way to Iceland which is textbook -AO and -NAO. This is why the long range guidance was so snowy. The raw NAO index has been skewed by the much stronger EA patterns in recent years. So the pressures to the south haven’t been as low. The blocking to the north hasn’t been the issue. It’s been the expansion of the subtropical ridges both in the Eastern US and Europe. So the lack of a trough especially near Europe caused the NAO to register as a weaker negative than the -5 AO was able to register. So a function of the way the indices are calculated and not a lack of blocking to the north. The current batch of computer models aren’t able to handle these new weather regimes especially the further out the forecast gets. The long range very snowy model forecasts in February reflected the old patterns which did indeed produce heavy snows down to the I-95 corridor. They would have been correct in the past keying on the heavy snowfall potential with the strong blocking to our north. But as the forecast period approached the models corrected much stronger with the Pacific Jet and Southeast Ridge. This has been a repeating theme with the models not being able to see the Southeast Ridge and Pacific Jet intensity very well beyond 5 days or so. The model forecasts missed the further north Southeast Ridge and stronger Pacific Jet which pushed the heaviest snows down axis up into Canada with the record snows from Toronto to Montreal.

It’s going to be a challenge getting anything resembling dry summer heat here with so much summer onshore flow and high dewpoints. Seems like you could really enjoy a Las Vegas or Phoenix summer pattern. It’s a really beautiful part of the country if you can tolerate that kind of heat.

The high latitude blocking pattern this February was in no way hostile to snowfall in the Northeast. It was right up there with past Februaries which produced historic KU blizzards. The issue was the northward displaced storm track and record Northern Stream of the Pacific Jet. This is conjunction with the strong Southeast Ridge and warmth when the bock peaked lead to the record snows getting displaced closer to Toronto and Montreal. While it rained with 50s along the coast around NYC Metro.

Ambient 500 mb heights have been increasing unevenly with some areas like the Aleutian Ridge seeing more increases than other areas. Boston’s best winter for snowfall was the record +NAO December to March in 2015. So it was less about the NAO than the deep trough over the Northeast. The main reason that the -NAO patterns have been underperforming for us in the 2020s is the trough that used to be present near the Northeast has been getting crowded out by the expansion of the Southeast Ridge or WAR. So even during extreme blocking events like this last winter, the storms still cut through the Great Lakes with a -5 -AO. The -5 AO back on 2-15-25 also extended eastward over to Iceland. So it should have also registered a strong -NAO also. But maybe the higher heights further south closer to Europe affected the calculation. So the lack of a KU blizzard around 2-15-25 was more about the storm track through the Great Lakes and Southeast Ridge link up than it was about the blocking near Greenland and Iceland.

Ensembles continuing with the slow moving cutoff theme for the extended Friday to Monday Memorial Day weekend.

That’s why this goes beyond the PDO and ENSO. We didn’t used to get these mega Aleutian Ridges and Southeast Ridges during -PDO and La Niña intervals of the past. Plus we are getting new patterns coinciding with the marine heatwaves from the Western to Central Pacific leading to historic 2nd EOFs of the PDO. This is why the ENSO and PDO events of recent years are behaving diffferently and creating different sensible weather patterns for us. The much stronger Northern Stream of the Pacific Jet has shifted the winter storm track through the Great Lakes. So this has created the record low snowfall pattern for us since 2019.

The Aleutian Ridge prior to 2019 was much weaker on an annual basis than it was compared to 1999-2018. I separated the 1999 to 2024 years into smaller periods in order to show the progression. So this is a new pattern coinciding with the rapid expansion of marine heatwaves in recent years. Also notice how the brief relaxation of this pattern over the winter had no staying power. Now we are back to the much stronger ridging SW of the Aleutians.

Yeah, there was a small cooling influence from the nearby trees back in 1966 in Central Park compared to the other areas. But nothing as big as we would see today under the canopy that has grown over the ASOS. That was a 250 to 500 year drought around our area. But instead we have seen multiple 500 year to 1000 year floods here. So if that was ever repeated in this much warmer climate, then most of the area would be in the 110° to 115° range with westerly flow. So we have been fortunate that this warmer climate has come with more onshore flow. The drought was very modest in 2010 to 2011 compared to those days. So I would add 5-7 degrees to the 2010-2011 highs if we got as dry as the 1960s. This is similar to what happened in the Pacific NW back in 2021 with the record drought and all-time high jumps around 6° higher than previous records. Remember, we had two baseline jumps in global temperatures since 2010-2011. Data for January 1, 1966 through December 31, 1966 Click column heading to sort ascending, click again to sort descending. NY LAGUARDIA AIRPORT WBAN 107 NJ NEWARK LIBERTY INTL AP WBAN 105 NY NEW YORK AVE V BROOKLYN COOP 105 NY PORT JERVIS COOP 104 NY NEW YORK LAUREL HILL COOP 104 NJ LITTLE FALLS COOP 104 NY JFK INTERNATIONAL AIRPORT WBAN 104 NY ISLIP-LI MACARTHUR AP WBAN 104 NJ ELIZABETH COOP 103 NJ CANOE BROOK COOP 103 NY NY CITY CENTRAL PARK WBAN 103 NJ ESSEX FELLS SERVICE BLDG COOP 103 NJ PATERSON COOP 103 NY MINEOLA COOP 103 NY WEST POINT COOP 103 CT NORWALK GAS PLANT COOP 103 Data for January 1, 2010 through December 31, 2011 Click column heading to sort ascending, click again to sort descending. NY MINEOLA COOP 108 NJ NEWARK LIBERTY INTL AP WBAN 108 NY WANTAGH CEDAR CREEK COOP 107 NJ CANOE BROOK COOP 107 NJ HARRISON COOP 107 NJ RINGWOOD COOP 106 NY MOLLOY CERCOM COOP 105 NJ TETERBORO AIRPORT COOP 104 NJ PLAINFIELD COOP 104 NJ CRANFORD COOP 104 NY LAGUARDIA AIRPORT WBAN 104 NY NY CITY CENTRAL PARK WBAN 104 NJ TETERBORO AIRPORT WBAN 104 CT DANBURY COOP 104 NY JFK INTERNATIONAL AIRPORT WBAN 103 NY WEST POINT COOP 103 Time Series Summary for Olympia Area, WA (ThreadEx) - Jan through Dec Click column heading to sort ascending, click again to sort descending. 1 2021 110 0 2 2009 104 0 - 1981 104 0 3 1994 102 0 4 2006 101 0 5 2024 100 0 - 2023 100 2 - 1998 100 0 - 1978 100 0 - 1961 100 0 - 1960 100 0 - 1956 100 0

The actual climate and weather speaks in patterns and not narratives. The Dust Bowl was a manmade event caused by removing the topsoil in the Plains leading to desertification of the Great Plains. So what would have been a run of the mill drought turned into a disaster which forced migration to other parts of the country. So of course the summer highs over a few years would set records just in the drought areas which became deserts back in those days. Other states and parts of the country which didn’t experience those conditions have already surpassed the temperatures they recorded in the Plains. So narrowly focusing more on the Great Plains than the rest of the world which has greatly surpassed the warmth of the 1930s completely loses perspective.

We are really lucky that we haven’t had a severe summer drought with westerly winds in this much warmer climate. Some of most impressive warmth over the last decade has occurred during the winter. When we hit 80° back in February 2018 it was a 4° jump over any previous February high. In the summer that would translate into 112° at Newark, 110° to 111° at LGA or the warmer zone near Corona, Queens.

All those 1934 records were the result of the farmers essentially turning the Great Plains into a giant paved over parking lot by removing the top soil. If we had maintained the same practices and not expanded the irrigation to record levels since then, those figures would get surpassed at least once every decade. The record monthly low of 70° for May at International Falls the other day is more impressive than any of those 1934 records. Simply for the fact that INL is one of the most rural areas in the U.S. and it’s on the Canadian Border. Anytime you see a record like that in what is considered the icebox of the U.S. you have to take notice. While the new all-time May max was only exceeded by 1°, that 70° minimum is 4° warmer than any other on May minimum on record for INL. It’s also the earliest 70° minimum by over a month. Top 5 warmest May minimum temperatures at International Falls Time Series Summary for INTERNATIONAL FALLS INTL AP, MN - Month of May Click column heading to sort ascending, click again to sort descending. 1 2025 70 19 2 1992 66 0 - 1988 66 0 3 1991 64 0 - 1919 64 0 4 2018 63 0 - 2014 63 0 - 1986 63 0 5 2021 62 0 - 2007 62 0 - 1980 62 0 - 1955 62 0 - 1918 62 3 First/Last Summary for INTERNATIONAL FALLS INTL AP, MN Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. 2025 05-12 (2025) 70 - - - 1995 06-17 (1995) 70 06-17 (1995) 70 0 2020 06-17 (2020) 70 06-17 (2020) 70 0 2001 06-25 (2001) 71 08-05 (2001) 77 40 2002 06-29 (2002) 70 09-08 (2002) 73 70

A minimum of 70° there this time of year is ridiculous. Would be the equivalent of an 84° low at LGA in May. So some pretty extreme stuff.

The most impressive heat this month is up by International Falls. So an early clue as to where the strongest summer heat may be focused closest to the drought feedback zones in the Western U.S. to the Plains. The new all-time May high of 96° would be the same as 100° here in May. RECORD EVENT REPORT NATIONAL WEATHER SERVICE DULUTH MN 414 AM CDT MON MAY 12 2025 ...RECORD DAILY AND MONTHLY HIGH TEMPERATURES SET AT INTERNATIONAL FALLS MN YESTERDAY... A RECORD DAILY HIGH TEMPERATURE FOR MAY 11 OF 96 DEGREES WAS SET AT INTERNATIONAL FALLS MN YESTERDAY. THIS BREAKS THE OLD RECORD OF 83 DEGREES SET IN 1991 AND TIED IN 1993. A RECORD MONTHLY HIGH TEMPERATURE FOR THE MONTH OF MAY WAS ALSO SET AT INTERNATIONAL FALLS YESTERDAY. THE HIGH TEMPERATURE OF 96 DEGREES YESTERDAY BREAKS THE PREVIOUS RECORD OF 95 DEGREES SET ON MAY 21 1964.

Record warmth continuing into May. https://bsky.app/profile/climatecasino.net One for the record books -- May 9, 2025 was the hottest May 9th on record globally, with daily records dating back to 1940.

JFK is currently experiencing the longest 100° day drought on record at 4316 days due to the increased onshore flow since 2013. Number of Consecutive Days Max Temperature < 100 for JFK INTERNATIONAL AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Period of record: 1948-07-17 to 2025-05-12 1 4316 2013-07-19 through 2025-05-12 2 4016 1999-07-06 through 2010-07-03 3 4009 1972-07-24 through 1983-07-15 4 3610 1983-08-21 through 1993-07-08 5 2210 1966-07-05 through 1972-07-22 6 2185 1993-07-11 through 1999-07-04 7 963 1960-05-02 through 1962-12-20 8 857 1955-03-18 through 1957-07-21 9 817 1951-11-07 through 1954-01-31 10 736 1948-08-28 through 1950-09-02

It looks like we are on track for no 90° days this month at the warmer spots like Newark which usually get them. So if the past experience continues with the exception of 1983 which was a super El Niño, this summer won’t see as many 90° days as the big years like 2022 and 2010 did. So an under 40 days reaching 90° season. But we could still see warm intervals and even 100° heat away from the shore with another warmer than average summer. Though the greatest heat may be back closer to the Plains and West this summer where the strongest drought feedback currently is. All May years at Newark with no 90° days Monthly Number of Days Max Temperature >= 90 for NEWARK LIBERTY INTL AP, NJ with no 90° days in May Click column heading to sort ascending, click again to sort descending. 2020 0 0 5 17 9 0 0 31 2014 0 0 2 8 2 3 0 15 2009 3 0 0 1 10 0 0 14 2008 0 0 6 11 2 3 0 22 2005 0 0 10 11 12 4 0 37 2003 0 0 5 8 7 0 0 20 1997 0 0 7 10 3 0 0 20 1990 2 0 5 9 9 1 0 26 1989 0 0 4 12 8 3 0 27 1984 0 0 8 6 8 0 0 22 1983 0 0 7 15 11 7 0 40 1982 0 0 1 10 1 0 0 12 1976 2 0 7 2 4 0 0 15 1973 0 0 5 9 12 5 0 31 1972 0 0 0 16 4 1 0 21 1971 0 0 6 7 7 2 0 22 1968 0 0 4 9 9 1 0 23 1967 0 0 5 1 1 0 0 7 1966 0 0 10 14 8 1 0 33 1963 0 0 6 11 3 0 0 20 1961 0 0 4 13 8 9 0 34 1960 1 0 3 2 8 1 0 15 1958 0 0 2 11 6 2 0 21 1954 0 0 5 10 3 0 0 18 1952 0 0 8 17 2 4 0 31 1950 0 0 8 6 3 1 0 18 1946 0 0 5 5 2 0 0 12 1940 0 0 2 11 1 1 0 15 1938 0 0 4 4 9 0 1 18

Yeah, that was the elevation snows back in 2013. https://weather.com/storms/winter/news/snow-new-england-new-york-weekend-20130527

Over the last 10 years there have been many extended Memorial Day weekends with at least some measurable rainfall on at least one day. This has been par for the course. Maybe related to all the blocking in Canada this time of year coupled with the tendency for lows to cutoff. We can all remember the record low maxes a few years ago. Newark Area, NJPeriod of record: 1931-01-01 through 2025-05-12DateLowest maximum temperatures (degrees F)Top Record 2nd Record 3rd Record 5/29 52 in 2021 60 in 1950 60 in 1940 5/30 53 in 2021 53 in 1953 59 in 2017

If recent years are a guide, then at least one of the Friday to Monday extended weekend days feature some measurable rain but it won’t be a washout.

1993 was the leader in 95° and 100° days at Newark. You can see how much warmer our summers have become since 2010. Even though 2010 and 1993 still stand at the top, many other years haven’t been far behind. This is mostly due to the onshore flow influence. If we ever got westerly flow and a real summer drought, then this records would easily be eclipsed in this much warmer climate than 2010 and 1993. 95° days at Newark Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. 1 1993 25 0 2 2010 21 0 3 2022 20 0 - 1988 20 0 - 1944 20 0 4 2021 18 0 5 2012 17 0 - 2011 17 0 - 2002 17 0 - 1955 17 0 6 1949 16 0 7 2005 14 0 - 1953 14 0 8 2016 13 0 - 1999 13 0 - 1991 13 0 - 1987 13 0 9 1994 12 0 - 1983 12 0 - 1966 12 0 10 2018 11 0 - 1973 11 0 100° days Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. 1 1993 9 0 2 1949 8 0 3 2022 6 0 - 1953 6 0 4 1988 5 0 - 1966 5 0 5 2011 4 0 - 2010 4 0 - 1955 4 0 - 1944 4 0

95° and 100° days were close in 2022 to 2010 in NJ. 2022 95° days Data for January 1, 2022 through December 31, 2022 Click column heading to sort ascending, click again to sort descending. Newark Area ThreadEx 20 NEWARK LIBERTY INTL AP WBAN 20 FREEHOLD-MARLBORO COOP 16 HARRISON COOP 16 SOUTH JERSEY REGIONAL AIRPORT WBAN 16 CANOE BROOK COOP 14 LONG BRANCH-OAKHURST COOP 13 SOMERSET AIRPORT WBAN 13 HIGHTSTOWN 2 W COOP 12 INDIAN MILLS 2 W COOP 10 NEW BRUNSWICK 3 SE COOP 10 CALDWELL ESSEX COUNTY AP WBAN 10 ESTELL MANOR COOP 10 New Brunswick Area ThreadEx 10 MANASQUAN 1 NW COOP 10 NJ 100° days Data for January 1, 2022 through December 31, 2022 Click column heading to sort ascending, click again to sort descending. NEWARK LIBERTY INTL AP WBAN 6 Newark Area ThreadEx 6 SOMERSET AIRPORT WBAN 5 FREEHOLD-MARLBORO COOP 5 CANOE BROOK COOP 4 HARRISON COOP 4 2010 95° days Data for January 1, 2010 through December 31, 2010 Click column heading to sort ascending, click again to sort descending. WRIGHTSTOWN COOP 24 SOMERDALE 4 SW COOP 22 Newark Area ThreadEx 21 NEWARK LIBERTY INTL AP WBAN 21 MOORESTOWN 4 E COOP 19 ATLANTIC CITY INTL AP WBAN 18 Atlantic City Area ThreadEx 18 CANOE BROOK COOP 18 RINGWOOD COOP 18 ESTELL MANOR COOP 18 TRENTON-MERCER AIRPORT WBAN 17 Trenton Area ThreadEx 17 HARRISON COOP 16 SOUTH JERSEY REGIONAL AIRPORT WBAN 16 PENNSAUKEN 1N COOP 16 FREEHOLD-MARLBORO COOP 15 NEW BRUNSWICK 3 SE COOP 15 New Brunswick Area ThreadEx 15 2010 100° days Data for January 1, 2010 through December 31, 2010 Click column heading to sort ascending, click again to sort descending. Newark Area ThreadEx 4 WRIGHTSTOWN COOP 4 NEWARK LIBERTY INTL AP WBAN 4 HARRISON COOP 4 Trenton Area ThreadEx 3 FREEHOLD-MARLBORO COOP 3 TRENTON-MERCER AIRPORT WBAN 3 CANOE BROOK COOP 3 RINGWOOD COOP 3 SOMERDALE 4 SW COOP 3

Of course 90° days are increasing in the city. I showed you how the drop in 90° days is a function of measuring the temperatures under the trees in Central Park since 1995. Several areas had their warmest summer on record for 90° days as recently as 2022. The immediate South Shore isn’t representative of what most of this forum experiences in the summer. This is a function of the ridge extending east of New England and turning the flow more onshore. So the sea breeze fronts have been setting up north of JFK and the Southern State Parkway on Long Island. Very rare in recent years for the sea breeze fronts to remain along the South Shore beaches like they did from the 1990s to 2013. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=74&network=CTCLIMATE&station=CT1762&season=all&dir=above&var=high&threshold=90&year=1950&_r=t&dpi=100&_fmt=png

90° days have been increasing across the entire region. The only areas that haven’t seen a big increase are at near the immediate shore. But most people live away from the immediate shore areas.

Yeah, spring 90° days at Newark have been increasing at a much slower rate than 50° and 60° days during the winter. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=74&network=NJCLIMATE&station=NJTEWR&season=winter&dir=above&var=high&threshold=50&year=1893&_r=t&dpi=100&_fmt=png

Looks like another over the top warm up this week. We could actually see the heaviest rains to our south instead of to the north which is different from the recent pattern. Then we cool down closer to average for late May with the wet pattern continuing. May 12-19 May 19-26