bluewave

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.