bluewave

I think the cooler February reference was in regard to long ranger seasonal models like the CanSIPS and EPS monthly which had the cooler stock February El Niño composite for the Mid-Atlantic.

A top 10 warmest spring for many and some areas also top 10 driest.

Shifting back to the over the top warming pattern with temperatures approaching 100° in Montana and cooler to the south.

Yeah, a super El Niño can actually be warmer than expected when overlapping with Niña-like influences. First, the westward lean to the forcing back to MJO 7 probably helped drop the Nino-ridge further south than is typical for El Niño in February. Then the big ridge east of Japan and the strong +WPO along with the EPAC Nino forcing carved out a trough just off the West Coast leading to the -PDO. So the Nino trough typically in the Mid-Atlantic was suppressed out toward Bermuda. Also note the Aleutian Low splitting with a piece over the Bering and just off the West Coast. The one bright spot that month was the record STJ streak near DC and narrow snow band into Central NJ. But it was too narrowly focused to extend much beyond the localized geographic region.

Stations in NJ will finish spring near first place for the most 90 days. Time Series Summary for HARRISON, NJ - Mar through May 90° Days Click column heading to sort ascending, click again to sort descending. 1 2026 7 5 2 2018 6 0 3 2001 5 2 4 2021 4 0 - 2016 4 0 - 2010 4 10 - 2004 4 2 - 2002 4 3 5 2022 3 0 - 2017 3 0 - 2009 3 13 - 2006 3 1 - 2000 3 4 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Mar through May Click column heading to sort ascending, click again to sort descending. 1 1991 8 0 2 2026 6 5 - 1986 6 0 3 2002 5 0 - 1959 5 0 - 1896 5 0 4 2022 4 0 - 2021 4 0 - 2018 4 0 - 2000 4 0 - 1987 4 0 - 1977 4 0 - 1965 4 0 - 1939 4 0 Time Series Summary for NEW BRUNSWICK 3 SE, NJ - Mar through May Click column heading to sort ascending, click again to sort descending. 1 2026 6 5 2 2016 4 0 - 2010 4 0 - 1976 4 0 3 2021 3 0 - 2017 3 0 - 2012 3 0 - 2009 3 0 - 2002 3 0 - 2001 3 1 - 2000 3 0 Time Series Summary for SOMERSET AIRPORT, NJ - Mar through May Click column heading to sort ascending, click again to sort descending. 1 2026 5 5 2 2021 4 1 3 2022 3 0 - 2017 3 0 - 2012 3 0 - 2009 3 0 - 2002 3 0 - 2000 3 2 Time Series Summary for SUSSEX AIRPORT, NJ - Mar through May Click column heading to sort ascending, click again to sort descending. 1 2026 3 6 - 2022 3 4 2 2023 2 0 - 2018 2 0 - 2013 2 5 - 2009 2 1 - 2002 2 0

Yeah, the PDO was able to be positive during the 1995-1996 weak La Niña winter. This weak La Niña winter had the ridges and troughs in the same general locations. But notice how the ridges this winter were so much stronger leading to the much warmer CONUS and less snowy outcome than 1995-1996. We can see the ridge extension to the east of a Japan during DJF preventing the PDO from going positive. Plus the more volatile NAO these days didn’t allow the -NAO to persist into the spring like we had back in 1995-1996. So March turned out to be a reversion to the warmer and less snowy 2020s mean.

Main issue has been the 500mb ridge east of Japan warming the SSTs below. So even though we have sufficient warming in the EPAC with the record +PMM, the warm pool under the ridge east of a Japan brings down the PDO. Long range models like the CFS have struggled with this ridge in their forecasts. So like we saw last summer, the actual readings verified significantly lower. FWIW, the CFS continues with the -PDO at least into early next winter due to the warm pool and ridging east of Japan persisting.

3rd spring in a row with the coolest high temperature departure occurring in May. Several spots have had a top 10 warmest spring so far. Very impressive temperature swings both earlier and later in the spring over short periods.

To the extent that we don’t typically see all 3 Memorial Day extended weekend days with measurable rain. The last time for NYC was back in 2021. Plus this weekend will rank very high on the rainiest Memorial Day weekends list.

Most of the guidance missed the record 100° heat last week from the long range guidance earlier in the month. Models don’t do very well with extremes beyond the week one and week two forecast periods. My guess is that the guidance beyond 15 days just reverts to whatever ENSO climo applies to the situation. In this case it was the usually cooler May climo it was forecasting to continue. So it missed the strong MJO 4-6 pulse which is very warm in the East. This was also why the Euro and other seasonal models missed the warmth in the East for the 2023-2024 super El Niño. They had the stock El Niño composite with a deep trough in the East. Instead we got the record MJO 4-6 pulse with the more Niña-like January 2024 even with the recent +2.1 ONI in Nino 3.4. So the long range model forecasts were reverting to the typical El Niño 500mb composite. Something similar happened in December 2015 with the long range model forecasts missing the record warmth in the East due to the record MJO 5. So long range models like to forecast just for whatever the ENSO is and they can’t resolve the MJO activity in the IO to WPAC. The record warm pool there has been resulting in more frequent and stronger MJO 4-7 activity than the old days when the SSTs were significantly cooler there.

Top 3 low max territory with the onshore flow, clouds, and rain. It has been a common theme in late May and early June since 2013. This one feels much cooler relative to the 95° to 100° heat this past week. Islip Area, NYPeriod of record: 1963-09-05 through 2026-05-23DateLowest maximum temperatures (degrees F)Top Record 2nd Record 3rd Record 5/21 49 in 1990 54 in 2000 56 in 2025 5/22 53 in 2025 54 in 2003 57 in 2000 5/23 54 in 2003 54 in 1982 56 in 2026 5/24 56 in 1982 57 in 2003 57 in 1969 5/25 49 in 1967 51 in 2013 51 in 2005 5/26 52 in 1967 53 in 2003 57 in 1973 5/27 56 in 1974 57 in 1973 58 in 1983+ 5/28 60 in 2014 60 in 2009 60 in 1996+ 5/29 51 in 2021 58 in 2017 60 in 1996+ 5/30 52 in 2021 60 in 2017 61 in 1965 5/31 55 in 1984 61 in 1967 63 in 1992 6/1 57 in 2015 63 in 2009 63 in 2003+ 6/2 53 in 2015 59 in 1997 60 in 1976 6/3 61 in 1997 62 in 1988 62 in 1986 6/4 58 in 2003 63 in 1988 63 in 1979 6/5 58 in 2009 62 in 1993 62 in 1985+ 6/6 56 in 2017 58 in 2004 60 in 2000 6/7 56 in 1982 61 in 2006 63 in 2002

Much stronger WPAC warm pool compared to 1997 at the same time.

The closest that we got in the 2020s at a station with a long enough period of record to a monthly record low was in May 2020 with the 3rd coldest monthly minimum at Newark. The last time we had a #1 coldest monthly minimum and all-time low around the area was in January 1994 in Sussex ,NJ. It’s much more common these days to have a top 5 warmest monthly max like the other day with the 100° heat away from the sea breeze. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of May Lowest Minimum Temperature Click column heading to sort ascending, click again to sort descending. 1 1861 31 0 2 1947 33 0 - 1907 33 0 - 1855 33 0 3 2020 34 0 - 1903 34 0 - 1900 34 0 - 1874 34 0 - 1854 34 0 - 1851 34 0 4 1966 35 0 - 1943 35 0 - 1913 35 0 - 1911 35 0 - 1905 35 0 - 1891 35 30 - 1880 35 0 - 1867 35 0 5 1978 36 0 - 1939 36 0 - 1876 36 0 - 1875 36 0 - 1857 36 0 Time Series Summary for SUSSEX 1 NW, NJ - Month of Jan Lowest Monthly Minimum Temperature Click column heading to sort ascending, click again to sort descending. 1 1994 -29 4 2 1961 -25 0 3 1912 -24 3 4 1981 -22 0 - 1968 -22 1 6 1984 -21 0 Time Series Summary for HARRISON, NJ - Month of May Monthly Maximum Temperature Click column heading to sort ascending, click again to sort descending. 1 2026 100 9 2 2022 96 0 - 2016 96 0 - 2013 96 0 - 1996 96 4 3 2017 95 0 - 2010 95 2 - 2007 95 0 - 2001 95 0

The last time NYC had an above normal month for precipitation was back in May 2025 with the ongoing drought conditions since the fall of 2024. Monthly Total Precipitation for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. 2026 2.70 2.60 3.60 2.48 1.02 M M M M M M M 12.40 2025 0.61 2.60 5.52 3.25 6.58 2.46 4.03 2.21 2.76 4.08 2.09 3.38 39.57 2024 5.28 2.05 9.06 3.47 4.11 1.71 4.20 7.02 1.58 0.01 3.35 4.53 46.37

Looks like our biggest soaker of the spring so far coming in this weekend. The heaviest totals on the 20th were pretty localized in parts of Queens and NW Nassau. This looks more widespread and extended rather than all the rain falling in 1 hour or less like the other day.