Tsunami Simmons | Northeast Winter Outlook 2026–27 & 2027

Where the Pacific heat is sitting

August sea-surface temperature anomalies (°C) in the eastern Pacific (Niño 3) and central Pacific (Niño 4) for every strong or very strong El Niño since 1965, next to the NYC snowfall that followed. The further the orange bar outruns the blue, the more east-based the event.

EventNiño 3, eastNiño 4, centralNYC snow

2026 values from the CPC September discussion (August means); historical values from NOAA PSL HadISST, August. The two datasets differ slightly, but not enough to change the shape.

How 2026 stacks up against the three snow setups

From the 27-winter analysis: the three ways El Niño winters have produced big Northeast snow. The meters show my read of how well this winter matches each one.

1. Greenland block + mild, central-leaning El Niño

Poor match

Hit 4 of 5 times historically. The Pacific half already fails: the heat is in the east. The Atlantic half, a negative NAO, can't be forecast this far out.

1963–64, 1968–69, 1977–78, 2009–10

2. Central-Pacific "Modoki" El Niño

Essentially off the table

Needs Niño 4 at least as warm as Niño 3. Niño 4 is +0.1°C while Niño 3 is +2.5°C, the widest east-heavy gap in the record.

2002–03, 2004–05, 2014–15

3. Very strong east-based El Niño, southern jet storm lottery

Strong match

Mild overall, with one shot at a single blockbuster storm if a cold air mass times up with the southern jet. That worked 2 of 3 times for very strong events, but its two closest shape analogs both whiffed.

Hits: 1982–83, 2015–16. Misses: 1997–98, 1972–73

Regional snowfall map

Schematic zones, not to scale. Percent of normal seasonal snowfall, my estimate from the analog winters.

under 50% 50–70% 70–90% 90–110% over 110%

Zone	Snow	Precip	Temps

The calls

Winter 2026–27

Very strong, east-based El Niño at peak

NYC snow: 8–18" (best 12")
Philadelphia snow: 5–12" (best 8")
Chance NYC tops normal: ~10%
Chance of a 12"+ NYC storm: ~25%
Precip, Mid-Atlantic coast: 100–120%
Temperatures: Above normal

The seven strong, east-based analogs averaged 15.7" in NYC, and the two with the closest Pacific shape, 1997–98 and 1972–73, got 5.5" and 2.8". Precipitation ran near or above normal in most of them. It fell as rain.

Most likely timing for any real snow: late January through early March, when the source region is coldest and the southern jet is most active.

Winter 2027–28

Post-El Niño decline, likely toward La Niña

NYC snow: 18–32" (best 24")
Philadelphia snow: 12–22" (best 16")
Chance of La Niña or neutral: ~70%
Chance NYC tops normal: ~30%
Temperatures: Near normal

After the seven strong or very strong El Niños since 1965, the next winter was La Niña four times and neutral three times. NYC averaged 25.8" and topped normal twice, including 51.5" in 1966–67.

Main risk to this call: models still show lingering warmth into mid-2027. A slow decay, like 2015 into 2016, would push this toward the low end.

The analog winters

Every strong or very strong east-leaning El Niño, and what came next. Highlighted rows are the closest matches to 2026's Pacific shape. See every El Niño since 1950 →

El Niño winter	Aug Niño 3 − Niño 4	NYC snow	Precip during event	Big storm?	Next winter	NYC snow next
1997–98	+1.99	5.5"	107%	No	Strong La Niña	12.7"
1972–73	+1.83	2.8"	139%	No	Strong La Niña	23.5"
2023–24	+1.06	7.5"	126%	No	Neutral	12.9"
1965–66	+1.04	21.4"	52%	No	Neutral	51.5"
2015–16	+1.03	32.8"	89%	Yes, 27.3" on Jan 23	Weak La Niña	30.2"
1982–83	+0.86	27.2"	111%	Yes, Feb 11–12 blizzard	Weak La Niña	25.4"
1991–92	−0.22	12.6"	85%	No	Neutral	24.5"
2026–27	+2.40	Forecast 12"	Forecast wet	~25% odds	La Niña lean	Forecast 24"

What would change the forecast

A Greenland block

A sustained negative NAO in January or February is the one thing that has turned El Niño winters snowy. It can't be seen at this lead time. If it shows up, raise the numbers.

A sudden stratospheric warming

A polar vortex split is the most common way blocking develops mid-winter. Watch for it from late December on.

Niño 4 warming up

If the central Pacific catches up by November, this event looks more like 2015–16 than 1997–98. That means better storm odds, not a snowier season.

A western ridge

A persistent ridge over western Canada (a negative EPO) delivered 2014–15. It's the wildcard the analog set can't capture.

How this was built

Analog method using 27 El Niño winters since 1951. Sources: NOAA ONI classifications, NWS Central Park and Philadelphia records, CPC NAO and PNA indices, and NOAA PSL Niño 3 and Niño 4 SSTs. The current event's data comes from CPC's September 10, 2026 diagnostic discussion. The sample size is small, and regional numbers are scaled from the Central Park and Philadelphia records. Treat this as a probability lean, not a guarantee.