bluewave

The first week of October finished near the warmest on record for the CONUS. The average for the CONUS from October 1-7 on Prism was 64.54° or +5.2°. So we’ll have to wait a while longer to get the final number. October 2026 through the 7th….64.54° +5.2° Top 7 Warmest October for CONUS 1963…59.34° 2024…58.93° 1947….58.50° 2016….57.45° 1950…..57.45° 2015…..57.24° 2021…..56.95°

Even though the CFS is currently too cool in Nino 1+2, the updated seasonal model update still has an east based El Niño lingering into next June with strong WWBs continuing.

October is continuing the seasonal model error for at least one month out. The seasonal models from early September had the typical -EPO October El Nino ridge near Alaska and NW Canada.This has been the seasonal model forecast error since May. The month to date has the 500mb ridge shifted further south over the CONUS with lower heights near Alaska. The next week will add to this pattern lowering heights more near Alaska and maintaining the CONUS ridge. This will be the furthest south ridge position for an El Nino October even when just using the 1972,1982,1997,2015, and 2023 super composite. Month to date Forecast through October 19th October forecast issued in early September October El Niño composite

Impressive PWATs near 2.00” with post-tropical Isaias and a decent pocket of MUCAPE. So probably a 1” to locally 3” event where the best banding sets up from Sunday into Monday. Pattern warms up for a few days following the storm with the big ridge expansion. Wednesday looks like the peak of this warm up. If the front is slower allowing enough sun, then the usual warm spots in NJ could see low 80s. Interior sections could see first freeze next weekend. So an active pattern for mid-October.

It feels like we have started to see non-linear shifts following these major heat releases to the atmosphere from the accumulated excess heat stored in the oceans. If you think about it we had a very similar climate from the late 1800s through about 1982. Sure there was some warming from 1885 to 1982, but nothing all that dramatic. Since the coldest winters of that era occurred in the late 1970s. Then the 1982-1983 super El Niño gave a slight bump to temperatures which remained about steady until 1997-1998. Following the 1997-1998 heat release, the greatest warming occurred in the Arctic several years later from 2005 to 2012. So the state of the Arctic sea ice shifted to much younger around 2007 and continues to this day in the same range. Then the next major heat release in 2015-2016 dramatically warmed our winters to the point that places like NYC only saw their next long term colder winter after 2014-2015 a full 11 years later in 2025-2026. The major climatic shift following 2015-2016 was the rapid warming and ridge expansion east of Japan beginning around 2018-2019 which has lead to this persistent record -PDO run. The heat release in 2023-2024 lead to the warmest CONUS winter to that point. 2025-2026 finished close to the warmest also but our little corner of the world finally got a cold winter after 11 years. But the geographic footprint relative to the rest of the CONUS was very small. It didn’t take away from the fact that it was an enjoyable winter for many here. Nino 1+2 never fully cooled off following 2023-2024 and gave us the Nino-like December 2024 with the record +PNA for a La Niña. Now this is the first time 2 El Niños this strong have occurred only 3 years apart. It feels like the big shift following 2023-2024 was a warming of the EPAC which had been the one region of the planet that had resisted the warming through 2022-2023. Many papers were written about the famous EPAC cold tongue. Now this current warming there has exceeded anything that has occurred in the past. This event into 2027 is going to be the greatest heat release to a higher baseline than all the previous events. So we don’t fully understand the shifts that will occur following this jump to a much warmer climate as we head into the late 2020s and then early 2030s. This EPAC warming since 2023-2024 in the chart below has been unprecedented.

Even the ONI wasn’t able to fully capture the full magnitude of the warming with the 2023-2024 event. Key Mechanisms and Findings Dual Warming Centers: Unlike typical El Niño events that center primarily in the eastern Pacific, the 2023–2024 event featured asynchronous double spatial peaks, combining a central Pacific peak (driven by zonal advective and thermocline feedbacks) with eastern Pacific warming. [1, 2] Synergistic Amplification: The dual Pacific warming centers worked together with an eastward-extended North Atlantic jet stream to amplify sea surface temperatures across multiple tropical basins.[1] Record Temperature Impact: Sea surface temperature anomalies accounted for roughly 92% of the interannual global warming spike, pushing the July 2023–June 2024 average global mean surface temperature to a record 1.58 °C above pre-industrial levels. [1]

A big question going forward is what does the future relationship look like in regard to the equatorial trade winds vs WWBs following such an enormous warm pool push from the WPAC to EPAC?

The Euro going into late winter and spring still has ENSO values warmer than any event had during the Nov-Dec peaks in the past.

Yeah, these “I” storms usually occur when the hurricane season is at its peak so it’s the most-retired letter.

Probably a secondary underlying factor overlapping with both ONI and RONI. Since we have had much stronger GOA lows in the past with similar RONI values. 1986-1987 had a much more expansive GOA-NP low than 2023-2024 with both RONI values near +1.5. Also note the much weaker GOA low in 2015-2016 than 1997-1998 despite identical RONI values of +2.3. My guess is this is a similar phenomenon we have been observing with all ENSO states. The 500mb ridges have become much stronger and expansive relative to the low pressure troughs. These stronger ridges have been driving the persistent -PDO and +AMO. So the warmer SSTs in the mid-latitudes are probably helping to cause a feedback loop. This area is outside the RONI band in the tropics.

RONI is not meant to be used for the absolute intensity of this event. It’s more about gradients and storm tracks. With something this historic, it’s the absolute temperatures and water vapor increase that matter which is better reflected by ONI.

Luckily, my power was only out for 24 hrs. Took down a bunch of trees. But borderline TS to Cat 1 systems don’t get retired unless they cause historic flooding like Agnes in 1972.

First frost of the season here on the cartops with a low of 36°. https://www.weather.gov/wrh/timeseries?site=khvn

The names only get retired if they cause significant enough effects. While the first Isaias gave me my strongest wind gusts to 78 mph back in SW Suffolk, it didn’t produce wide enough damage as a weaker hurricane and then tropical storm to have the name retired. Many big majors get retired along with weaker systems which produce historic rainfall.

This may be the first time we had effects from the same named hurricane twice in the same decade. We had Hurricane Isaias for the first time in 2020. Now it looks like we’ll see the remnants of Isais later Sunday into Monday. If we can get some measurable rain by Sunday evening, it will mean most weekends since early July had rain. https://en.wikipedia.org/wiki/Hurricane_Isaias_(2020)

Starting to see +12C subsurface anomalies as Nino 3.4 reaches +3.4 for the first time.

Even with these CFS WWB forecasts being too weak leading to unrealistically low Nino 1+2 values, it increases the WWBs again over the winter and continues into next summer.

The comparison was to a low tracking in directly from the east over NYC like last week which would be further north than December 1992 that came into the Delmarva.

I was on Long Island for the 1992 Nor’easter. The biggest impact was the record coastal flooding up to that time and hurricane force easterly gusts. We got 3-5” of rain followed by some light snows when the low departed. That event was further south near the Delmarva than the low which tracked right into NJ in September from the east. Data for December 9, 1992 through December 13, 1992 Total precipitation Click column heading to sort ascending, click again to sort descending. NJ TETERBORO AIRPORT WBAN 4.74 NJ JERSEY CITY COOP 4.68 NJ ESSEX FELLS SERVICE BLDG COOP 4.40 CT NORWICH PUBLIC UTILITY PLANT COOP 3.69 NY WESTCHESTER CO AP WBAN 3.66 NY PATCHOGUE 2 N COOP 3.60 NY LAGUARDIA AIRPORT WBAN 3.59 NY PLEASANTVILLE COOP 3.57 NY MINEOLA COOP 3.54 NY NEW YORK AVE V BROOKLYN COOP 3.52 NY NY CITY CENTRAL PARK WBAN 3.45 NJ CHARLOTTEBURG RESERVOIR COOP 3.40 NJ CANOE BROOK COOP 3.30 NY JFK INTERNATIONAL AIRPORT WBAN 3.25 NY PORT JERVIS COOP 3.22 NJ NEWARK LIBERTY INTL AP WBAN 3.19

December 1992 was a big rainstorm in Southern New England shoreline areas and NYC Metro. I guess our definitions of the geographic regions are a little different. To me anything north of the Hartford to Providence line is Central New England. That event came into the Delmarva. So a retrograding system right into NJ would probably be mostly rain in the same regions which got rain in December 1992. Plus during the 1997-1998 winter the ridge axis was further north along with the 540 thickness line than 92-93 or the 91-92 winter. The January 1992 nor’easter which got pulled in from the east was also a big rainstorm for the NYC Metro area.

During the winter the antecedent warmth with a seasonally stronger STJ than the fall would prevent much snow from getting south of Central and Northern New England with a loop in from the East. We saw tracks like this but even further south during the January 1992 Nor’easter which got pulled in from the east and also. Plus December 1992 came in closer to the Delmarva and you had to be pretty far north to cash in on that one compared to NYC Metro.

Only for Central to Northern New England since it tracked directly into the Jersey shore.

Very impressive Southeast ridge in the means since March. So just a continuation of the ongoing pattern. Very 1997-1998 type storm track forecast with the tropical low lifting north from the Gulf through the East into early next week. Sometimes these October storm tracks are an early indication of what we get during the winter. But this is a much stronger east based event than that one was.

Sometimes these October storm tracks can give us an early indication of what we will see for the winter. The OP Euro and the AIFS track the system from the Gulf up through our area by later Sunday into Monday. This was one of the active storm tracks during the 1997-1998 super El Nino. This is also an east based event but much stronger than that one was.

Very impressive to get a near record 594+dm Southeast ridge during an El Niño October. So a continuation of the ridge axis located further south than usual since last May. The typical -EPO October El Niño ridge will probably finish this month the furthest south for an El Niño October.