bluewave

Very warm early June pattern with 90s next few days then a pullback and more 90s next week. As we saw with the early 100° heat back in May, this is warmer going into at least the early summer than past super El Niño events The extensive nature of the +30C warm pool from the IO over to the PMM region has resulted in competing Niña-like and Nino-like influences. The warmest days are what we typically see with La Niña early in the summer. The recent cooler from the Memorial Day weekend to a few days ago were more Nino-like. But the warmer days were of a higher magnitude than the cooler days were. Some spots set or tied their all-time May monthly maximum temperatures. It could also be the drought feedback across the CONUS is contributing to this unusual early summer warmth for a super El Niño. Along with the -PDO and continuing warm pool east of Japan. Plus these are our first super El Niños only 3 years apart leading to another global baseline temperature jump over such a short period of time.

MJO 7 is the bridge between the super El Niño and the WPAC warm pool. So we get an extended +30C warm pool from the IO over to MJO 7 and Nino 4. It’s even possible that the 30C warm pool could expand closer to Nino 3.4 by later in the fall. Plus the +30C warm pool associated with the record +PMM to the north of Nino 1+2. We began to see MJO 4-6 activity for the first time with a super El Niño in December 2015. As the warm pool expanded by the 2023-2024 super El Niño into the IO, we had record MJO 3-7 activity with a super El Niño. Multiple papers have bee published on this more active MJO from the IO into the WPAC. Previous events had seen the MJO go quiet in these passes during super El Niños through the 1997-1998 event. They even released a paper calling it dual forcing back in 2023-2024 due to how large the warm pool had grown. All this extended oceanic heat that was released jumped the global baseline higher than the models forecast. So getting another baseline temperature jump only 3 years later will be a first for our modern climate.

I use it now along with the climate reanalyzer for composites We can see why many have been noticing that despite the record developing El Niño, the sensible weather is more Niña-like. Record 100° heat a few weeks ago and the 90s reloading in a few days is probably reflecting the westward lean of the Nino forcing. The cooler days in between are probably more of a Nino-like influence with the recent snows in the New England higher elevations.

The current pattern is showing the competing influences. The typical June +PNA El Nino ridge is getting displaced further east than is usual near the Great Lakes. This is the position that we usually see this time of year with a La Niña or -PDO pattern. Probably related to the El Niño forcing shifted west closer to the WPAC +30 C warm pool and the -PDO. This would be a very warm pattern in the winter like we saw in 23-24 with the Nino ridge pressing further east than usual. If the trough can return mid month closer to the Great Lakes, then probably it would reflect the Nino forcing shifting east of the Dateline at that time. So a periodic back and forth between WPAC to Central and EPAC forcing.

Rare 30° June daily temperature range on Long Island with how dry it has been. It was the 4 largest on record for Long Island during June. Big afternoon temperature jump following some spots with shorter periods of record recording a record low. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=139&network=NY_ASOS&zstation=FRG&v=largest&month=jun&_r=t&dpi=100&_fmt=png

The EPS weeklies actually did a decent job beginning in late October into November seeing the general 500mb pattern. But the Western ridge verified much stronger skewing the total CONUS significantly warmer. This allowed our area to beat the guidance to the colder side for a change. The first colder winter with above average snowfall in 11 years for our region made it really stand out against the sea of warmth since 2015-2016.

CanSIPS was too cold overall across the CONUS during the 2025-2026 winter. It verified as the 2nd warmest winter on record across the CONUS. To be fair none of the models correctly forecast how warm and expansive the Western ridge would become. This allowed the East to turn out colder for a change than the seasonal models such as the CanSIPS were forecasting. But the magnitude and geographic coverage of the cold was limited compared to the expansive and record breaking nature of the warmth.

The last two years have been very dry across much of the CONUS. It will be interesting to see how things go with the developing super El Niño. The current pattern has been alternating between surges of Niña-like warmth and cooler El Niño-like intervals from the spring into early summer so far. But we have still been averaging out warmer than is typical this time of year for such a strong developing El Niño. So not sure if the precipitation will fully shift into a more Nino-like wet pattern or we still hold onto some reflection this Niña-like drought pattern. Ridges have been significantly stronger than usual across much of North America in recent years. So the more expansive high pressure has tended to really dry things out.

The long range forecasts from the CanSIPS have a strong cold bias. Notice how the model had a cold spring especially in the Great Lakes and Northeast from the older forecasts. Didn’t really begin to catch on until the March 1st update. But even then it was too cold. Verification 2nd warmest spring on record for the CONUS Climatologist49 ‪@climatologist49.bsky.social‬ Follow Spring (Mar-May) temperature departure from the 1991-2020 normal. Seems warm. ‪Climatologist49‬ ‪@climatologist49.bsky.social‬ · 20h Spring 2026 was the 2nd warmest on record for the Contiguous U.S. (2012). A majority of locations had a top 5 warmest spring compared to all springs since 1895 and many places had their warmest. Only a small area of the northern Plains had a cool spring compared to the full period-of-record. 2:07 PM · Jun 1, 2026 Everybody

NYC hasn’t had a month with above normal precipitation since May 2025. So the last 12 months actually made the top 20 driest for June to May. This is impressive given the overall wetter pattern since 2003. Time Series Summary for NY CITY CENTRAL PARK, NY Driest 6-1 through 5-31 Click column heading to sort ascending, click again to sort descending. 1 1966-05-31 27.85 0 2 1950-05-31 30.86 0 3 1965-05-31 30.93 0 4 1930-05-31 31.46 0 5 1954-05-31 32.13 0 6 1911-05-31 32.59 0 7 1959-05-31 32.63 0 8 2002-05-31 32.73 0 9 1882-05-31 33.45 0 10 1962-05-31 34.16 0 11 1877-05-31 34.24 0 12 1957-05-31 34.82 0 13 1963-05-31 35.08 0 - 1887-05-31 35.08 0 14 1955-05-31 35.17 0 15 1925-05-31 35.28 0 16 2026-05-31 35.44 0 17 1981-05-31 35.58 0 18 1907-05-31 36.03 0 19 1932-05-31 36.06 0 20 1892-05-31 36.23 0

We have a record 30C warm pool from the IO over to Nino 4. So the Nino forcing is linking up with forcing near the Maritime Continent. This is part of the reason that the models have the warmth in Canada and across the Northern Tier states as we head into June.

Probably a function of the more Niña-like -PDO with the WPAC warm pool. Plus the ongoing drought. So another case of the 500mb ridges becoming stronger more expansive during the 2020s than we have typically seen in the past.

Back to 90s by later this week at the usual warm spots as the below average rainfall and drought continues.

The Nina-like WPAC warm pool forcing in DJF 2015-2016 and 2023-2024 did enhance the warmth in the Northeast those winters above the typical super El Niño winters like 1997-1998 and 1982-1983. While the PDO was positive in 2015-2016, we got the record MJO 5 in December adding to the historic +13 warmth. 2023-2024 had both a -PDO and strong MJO 4-7 activity. So both winters featured record Niña-like MJO activity for super El Niños. But even without the Niña influence in 1997-1998, that winter was still very warm. Plus the winters have warmed since 1997-1998. So perhaps that winter would be just as warm today as 2015-2016 and 2023-2024 was even without the La Niña influence. Since the stronger Southeast trough in 1997-1998 was all Pacific air with the record east based super El Niño. Top 15 warmest winters in NYC Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. 1 2001-2002 41.5 0 2 2022-2023 41.0 0 2015-2016 41.0 Super El Niño Nina Influence 3 2023-2024 40.6 Super El Niño Nina influence 4 2011-2012 40.5 0 5 1931-1932 40.1 0 6 1997-1998 39.6 Super El Niño No Niña influence 7 2016-2017 39.3 0 8 2019-2020 39.2 0 9 1990-1991 39.1 0 10 1998-1999 38.6 0 11 1948-1949 38.5 0 12 1889-1890 38.4 0 13 1952-1953 38.1 0 14 1982-1983 37.9 Super El Niño No Niña influence - 1936-1937 37.9 0 15 1996-1997 37.8 0 - 1932-1933 37.8 0

First time since 1988 here around HVN that the strongest May wind gusts occurred so late in the month. So an unusually strong late May storm system. Very impressive omega block for this time of year.

I think that it could also go beyond the RONI in that the 500 mb ridges are expanding in the mid-latitudes outside the tropical oceans which RONI measures. The 500 mb ridge across the North Pacific from east of Japan to south of the Aleutians has been unprecedented during the 2020s. Also note the slightly weaker mirroring of the pattern in the South Pacific to the east of New Zealand. So it’s been warming the SSTs underneath the ridge causing the -PDO to remain negative. In the old days ,the -PDO was more a function of colder SSTs off of California rather than the extensive warm pool from east of Japan to south of the Aleutians that we have today.

Yeah, we can see the overlapping influences between the El Niño, MJO, and -PDO heading into early June. The ridging showing up south of Alaska into Western Canada is the correlation with the El Nino and +AAM. The extension of the ridge further east across much of the CONUS is more -PDO and MJO 8-1 related for this time of year. So effectively a 500 mb composite in early June that reflects these influences. A coupled El Niño will vary in its sensible weather related to the other influences. Also the pattern in recent years of the 500 mb ridges becoming stronger and more expansive with weaker troughs during any given ENSO state.

Nice way to end the ski season up there.

My guess is that the recent drop was enhanced by the +EPO -PNA pattern in May.

Starting to see the seasonal -PDO drop heading into summer which has been common during the the 2020s.

Looks like that deep low dropping SSE from Canada will produce some strong wind gusts here tomorrow especially eastern sections.

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.