Every flood-producing nor'easter at Atlantic City, 1950–2026
Each dot is a nor'easter that pushed the Atlantic City tide to moderate flood stage (7.0 ft) or higher. Hurricane-driven floods like Donna, Belle, Gloria, Sandy, and Jose (2017) are excluded. Color shows the ENSO phase that winter. Dots after mid-2016 come from NOAA's verified tide record at the same gauge. Hover any dot for the storm.
Flood nor'easters per decade: 1950s 2, 1960s 3, 1970s 7, 1980s 4, 1990s 12, 2000s 10, 2010s 17, and 2020s already 11 through September 2026. No tide reached moderate flood stage in 2025 or so far in 2026; the highest were 6.8 ft, just short. Much of that climb is sea-level rise of roughly a foot since 1950, which lets storms that once fell short now reach flood stage.
What the last ten winters added
2016–17 through 2025–26, from NOAA's Atlantic City gauge: 18 more flood nor'easters in ten winters. The 1950s, 60s, and 70s had 12 combined.
Flood nor'easters per winter, 2016–2025
Flood nor'easters per decade
El Niño still leads
The three El Niño winters averaged 2 floods each, led by 2023–24 with three (January, February, and April 2024). Every one of them flooded.
But the gap is closing
La Niña and neutral winters now average 1.7 to 1.8, more than double their 1983–2015 rates. A foot of sea-level rise means an ordinary nor'easter on a high tide can do it.
Fall is the new flood season
6 of the 18 hit in September through November, including three in a row in fall 2024 during a neutral winter. Onshore wind plus a king tide is enough.
Small samples: three to four winters per phase. The three hollow dots (October 2020, October 2022, September 2023) had a tropical storm's remnants merged into the coastal low, so they aren't counted.
El Niño and flood nor'easters
Since sea level rose enough for moderate storms to reach flood stage, El Niño winters have produced about twice as many flood nor'easters as other winters. Before 1983, when fewer storms could clear the bar, there was no El Niño signal at all.
Flood nor'easters per winter, 1983–2015
Winters with at least one flood, 1983–2015
Flood nor'easters per winter, 1950–82
By El Niño strength, 1950–2015
Across the full 1950–2015 record, the El Niño edge (0.92 vs about 0.6 floods per winter, counting the May 2016 flood) is suggestive but not statistically significant (p ≈ 0.15 in the original analysis). It is consistent with published East Coast storm climatology, which ties more frequent winter storms to El Niño.
What the flood record says
Very strong El Niños are flood winters
1997–98 brought 3 moderate floods and 2015–16 brought 5, while both were near the bottom for NYC snow (1997–98 had just 5.5"). The storm energy was there. The cold air wasn't.
East-based events flood more
East-based El Niño winters averaged 1.00 flood nor'easters and a 7.5-ft+ flood in one of every three winters. Central-Pacific events averaged 0.77, with a 7.5-ft+ flood in only 1 of 13 winters.
The biggest floods sit under a block
The bigger the flood, the more negative the NAO. A Greenland block stalls the low offshore, and days of onshore wind stack water up over several high tides.
El Niño floods come early and mid-winter
Of 22 El Niño-winter floods, 6 came in October and 7 in January, with none in March. La Niña and neutral floods spread wider, including big March storms like 1962 and 1984.
The block rule for flooding
NAO during the month of each flood nor'easter on the original 1950–2016 list, compared with all October–March months.
| Group | Avg NAO that month | NAO negative | Change from prior month |
|---|---|---|---|
| All Oct–Mar months (baseline) | +0.04 | 46% | about 0 |
| All flood nor'easters (46) | −0.27 | 52% | −0.36 |
| 7.5 ft and higher (13) | −0.60 | 69% | −1.21 |
| 8 ft and higher (5) | −0.76 | 80% | −1.52 |
Floods and snow want opposite timing
Crippling snowstorms tended to fire as a block broke down, when the NAO was rising. Crippling floods happen as a block builds and holds, when the NAO is falling. It's the same pattern at different moments.
Sandy proves the rule
Sandy was tropical, so it's excluded from the counts. It reached 8.8 ft at Atlantic City in a month when the NAO plunged from −0.59 to −2.06. That block is what turned it left into New Jersey.
The biggest flood nor'easters
| # | Storm | Atlantic City peak | NAO that month | ENSO that winter |
|---|---|---|---|---|
| 1 | Dec 11, 1992, the December nor'easter | 9.0 ft | +0.47 | Neutral |
| 2 | Oct 31, 1991, the Perfect Storm | 8.6 ft | −0.19 | El Niño |
| 3 | Mar 6, 1962, the Ash Wednesday Storm | 8.4 ft | −2.47 | Neutral |
| 4 | Nov 25, 1950, the Great Appalachian Storm | 8.2 ft | −1.26 | La Niña |
| 5 | Mar 29, 1984 | 8.0 ft | −0.37 | La Niña |
| 6 | Oct 25, 1980 | 7.8 ft | −1.77 | Neutral |
| 7 | Jan 4, 1992 | 7.8 ft | −0.13 | El Niño |
| 8 | Jan 23, 2016, Jonas | 7.8 ft | +0.12 | El Niño |
| 9 | Jan 2, 1987 | 7.6 ft | −1.15 | El Niño |
| 10 | Mar 19, 1996 | 7.6 ft | −0.24 | La Niña |
The top floods are spread across all three ENSO phases. El Niño raises how often floods happen. The block, the tide cycle, and the storm's forward speed decide how bad a single one gets. Since 2016, the biggest were March 14, 2017 and October 27, 2018, both 7.6 ft, which would tie for 9th.
Layer 2: the snowstorm record
The sections below measure the same storms by what they drop, using NOAA's NESIS snowstorm scale, 1956–2022. Snow is the secondary impact, but it shows how El Niño changes storm intensity when cold air is available.
Every rated snowstorm, 1956–57 to 2021–22
Each bar is one winter. Stacked blocks are individual storms, sized by NESIS score, so taller blocks mean bigger storms. Bar color shows the ENSO phase that winter.
Snowstorms: frequency vs intensity by ENSO phase
El Niño winters have only slightly more storms. The gap opens up in how big those storms get.
Rated storms per winter
Major storms (NESIS 4+) per winter
Winters with a crippling storm (NESIS 6+)
Average NESIS per storm
A shuffle test on the 66 winters puts the El Niño major-storm edge at p ≈ 0.04, and the crippling-storm edge at p ≈ 0.02. Both are real signals, not just luck of the draw, though with a small sample.
Snowstorms before, during, and after El Niño
Major storms (NESIS 4+) per season in the winter before an El Niño, during it, and after it. Back-to-back El Niño winters are left out of the before and after groups so they aren't double-counted.
Major storms per winter
Winters with a crippling storm
Snowstorms by El Niño strength and flavor
The El Niño winters split by strength and by where the Pacific warming sat.
Rated storms per winter, by strength
Winters with a crippling storm, by strength
Central vs east-based: storms per winter
Central vs east-based: crippling-storm winters
What the snow record says
Intensity, not frequency
Storm counts run 1.67 per El Niño winter vs about 1.4 for La Niña and neutral. The average El Niño storm scores 4.0 on NESIS vs 3.2 in La Niña. The subtropical jet feeds Gulf moisture into coastal lows, so the ones that form carry more.
Moderate El Niños are the storm factories
Six moderate winters averaged 3.2 rated storms, and none came up empty: 1963–64, 1968–69, 1986–87, 1994–95, 2002–03, 2009–10. That lines up with the snowfall analysis, where moderate events were the snowiest.
Very strong means few storms, big ones
The three very strong winters averaged under one rated storm. Two of the three still produced a crippling one: February 1983 and January 2016. That's the "storm lottery" pattern again.
The winter before is quiet
Winters leading into an El Niño averaged 0.33 major storms, and none of the 18 produced a crippling storm. That is the weakest showing of any group.
The winter after is average, unless the event was strong
After any El Niño, major storms return to about normal (0.61 per season). After strong and very strong events, they drop to 0.29: only 2 of 7 winters produced a major storm.
Timing shifts to mid-winter
73% of El Niño-winter storms hit in January or February, and only 8% in March. La Niña and neutral winters put 30–35% of their storms in March.
The 15 highest-impact snowstorms
| # | Storm | NESIS | ENSO phase that winter |
|---|---|---|---|
| 1 | Mar 12–14, 1993, Superstorm | 13.20 | Neutral |
| 2 | Jan 6–8, 1996, Blizzard of '96 | 11.78 | La Niña |
| 3 | Mar 2–5, 1960 | 8.77 | Neutral |
| 4 | Jan 22–24, 2016, Jonas blizzard | 7.66 | El Niño |
| 5 | Feb 15–18, 2003, Presidents' Day II | 7.50 | El Niño |
| 6 | Feb 2–5, 1961 | 7.06 | Neutral |
| 7 | Jan 11–14, 1964 | 6.91 | El Niño |
| 8 | Jan 21–24, 2005 | 6.80 | El Niño |
| 9 | Jan 19–21, 1978 | 6.53 | El Niño |
| 10 | Dec 25–27, 1969, Post-Christmas storm | 6.29 | El Niño |
| 11 | Feb 14–17, 1958 | 6.25 | El Niño |
| 12 | Feb 10–12, 1983, Megalopolitan blizzard | 6.25 | El Niño |
| 13 | Jan 29–31, 1966, Blizzard of '66 | 5.93 | El Niño |
| 14 | Feb 5–7, 1978, Blizzard of '78 | 5.78 | El Niño |
| 15 | Feb 12–15, 2007, Valentine's Day storm | 5.63 | El Niño |
NAO timing around snowstorms
Does the North Atlantic Oscillation shift around nor'easters? In a typical winter month, the NAO moves about 0.87 from the month before. Storm months move more, and the direction depends on the storm type.
| Group | Avg NAO swing that month | NAO rising? | What it points to |
|---|---|---|---|
| Typical winter month | 0.87 | ~50% | Baseline |
| All 101 rated storms | 0.99 (p ≈ 0.01) | 43% | Storms favor months when the pattern is changing |
| El Niño majors (21) | 1.30 (p ≈ 0.003) | 33% | NAO dropping: a Greenland block building in |
| Crippling storms (12) | 1.00 | 75% | NAO rising: the block breaking down |
| Neutral-winter majors (11) | 0.63 | 64% | Steady pattern; driven from the Pacific side |
Big storms fire on the break
42% of crippling storms came in a month when the NAO was climbing out of negative territory, vs 30% of winter months overall. That fits the classic forecaster rule: the monster storm often fires as a block breaks down.
The Pacific ridge is the steadier signal
83% of crippling storms, and 90% of El Niño-winter majors, came in months with a positive PNA, a western ridge feeding cold air east. A negative NAO showed up in only half of them.
The neutral giants were Pacific-driven
March 1960, February 1961, and the 1993 Superstorm came in months with calm NAO readings. Two of the three had a strong western ridge, and all three were late-season storms where the northern and southern jet streams merged.
Based on monthly CPC NAO and PNA values. A daily ±10-day test is the next step and would sharpen these numbers.
Do hurricane seasons set up the winter's snowstorms?
Correlation between the hurricane season's total energy (ACE) and the following winter's rated storms. Bars right of center mean busier hurricane seasons were followed by more activity; bars left mean the opposite.
Hurricane ACE vs next winter's major storms
La Niña p ≈ 0.04, neutral p ≈ 0.01. El Niño and overall are not significant.
Hurricane ACE vs next winter's total NESIS
La Niña p ≈ 0.01. Using hurricane counts instead of ACE, the La Niña link is even stronger (+0.69).
La Niña: Atlantic heat is the fuel
Without El Niño's southern jet, Atlantic warmth becomes the limiting ingredient. The clearest case: the 1995 hurricane season was the 5th most active on record (ACE 227), and the Blizzard of '96 (NESIS 11.78) followed that January.
El Niño: the hurricane link disappears
El Niño suppresses hurricanes and boosts nor'easters at the same time. That cancels out any year-to-year link, which is why the all-winters number comes out near zero.
Neutral: quieter seasons, bigger winters
In neutral winters, majors followed quieter hurricane seasons more often. The three neutral giants followed near-average seasons with nearly identical ACE: 77, 73, and 76.
The Atlantic's slow cycle: two dials, not one
The Atlantic runs warm and cool phases lasting decades. Warm phases fuel both hurricanes and nor'easters. But the top-tier storms also track the decade's typical winter NAO, which controls blocking and the cold air supply.
| Era | Atlantic phase | Avg hurricane ACE | Typical winter NAO | Rated storms / winter | Majors / winter | Top-15 storms |
|---|---|---|---|---|---|---|
| 1956–69 | Warm | 103 | −0.52 (11 of 14 negative) | 1.71 | 0.79 | 6 (0.43 per winter) |
| 1970–79 | Cool | 69 | −0.17 (mixed) | 1.00 | 0.40 | 4 (0.16 per winter) |
| 1980–94 | +0.57 (2 of 15 negative) | |||||
| 1995–2009 | Warm | 135 | +0.11 (mixed) | 1.85 | 0.70 | 5 (0.19 per winter) |
| 2010–21 | +0.74 (2 of 12 negative) |
1960s: both dials up
A warm Atlantic plus a strongly negative NAO decade produced the densest cluster of great storms in the record, more than twice the rate of any later era.
Late '70s: El Niño overrides a cool ocean
The Blizzards of '78 and the February 1983 blizzard hit during the cool phase, when storm counts were at their lowest. Both came in El Niño winters as the NAO dipped. El Niño can beat the background for a single winter.
Since 1995: fuel without the block
The warm Atlantic brought storm counts back to their highest levels, but a mostly positive NAO kept the top-tier rate well below the 1960s. The 1956–69 and 1970–94 eras share one storm catalog, so the drop between them is real.
Where the dials sit in 2026
Few storms, but a real shot at one big one. That is the storm lottery.
The last warm phase lasted 37 years, so we're in the window where a turn could start. Accelerating background warming may blunt any true cool phase.
The eastern hurricane development zone ran about 0.5°C below average in spring, a big retreat from the 2023–24 records. It's one reason the hurricane season has been so quiet.
This is the nor'easter fuel tank, and it's full. Expect moisture-loaded coastal storms, with rain and mixing favored near the shore.
Storms that once topped out at minor flooding now reach moderate. The flood bar is effectively lower every decade.
Last winter averaged about −0.1, then March 2026 spiked to +2.69. There's no sign of a 1960s-style negative decade.
What this means for 2026–27 and 2027–28
- Flooding is the headline nor'easter threat this winter. A very strong, east-based El Niño, a record-warm Gulf Stream, and sea level about a foot above the 1950s all point the same way. The closest analogs, 1997–98 and 2015–16, produced 3 and 5 moderate floods at Atlantic City. My call is 2 to 4 moderate-or-worse flood nor'easters for the South Jersey coast and Delaware Bay shore, with at least one likely by January.
- Timing: El Niño flood nor'easters cluster in October and January. The season is already underway, with a Coastal Flood Warning in effect this week.
- The trigger to watch for a major flood: a Greenland block that builds and holds (the NAO falling sharply). That's the setup behind 4 of the 5 floods of 8 ft or more. Pair it with a new- or full-moon tide and the ceiling goes up.
- Snow is secondary: expect few snowstorms, probably 0–2 rated ones across the Northeast, with about a 25% chance of a 12"+ storm in NYC. If a big one comes, the window is mid-January to late February, as a block breaks down.
- 2027–28: after strong El Niños, flood activity holds near average (0.67 per winter, and 2 of the 5 biggest floods came in the winter after one), while big snowstorms tend to drop off. If La Niña arrives, an active 2027 hurricane season would raise the odds of a big nor'easter.
Method and limits
Flood nor'easters come from NWS Mount Holly's verified list of Atlantic City tide crests of 7.0 ft MLLW or higher (updated May 2016), limited to non-tropical storms from 1950 on. Hurricane and tropical-storm floods are excluded. Seasons run July to June and are classified by the Oceanic Niño Index. NAO values are CPC monthly indices. The gauge record has gaps and sea-level rise inflates recent counts. That's why the El Niño comparison is shown separately for 1950–82 and 1983–2015.
Update, September 2026: the NWS list stops in May 2016, so the record is extended with NOAA CO-OPS verified high/low tides for Atlantic City (station 8534720) through August 2026, plus preliminary data for September 2026. Thresholds are NWS Mount Holly's, converted to MLLW with NOAA's published datums (moderate 7.0 ft, major 8.0 ft). As on the NWS list, crests are rounded to the tenth of a foot, so 6.95 ft and up counts as 7.0; a check against 1996–2015 shows the list did the same. Tides within three days are one storm. Tropical storms are excluded after checking each date against the National Hurricane Center's HURDAT2 tracks, which removed Jose (September 2017). Three floods where a tropical remnant merged into the coastal low (Zeta 2020, Ian 2022, Ophelia 2023) are shown hollow and not counted. Seasons are classified with NOAA's ONI episode rule, which reproduces the 1983–2015 rates above exactly. Adding the May 5, 2016 flood (6.98 ft) moves 2015–16 from 4 to 5 floods, and the stats that include it are updated. The 1950–82 split, the full-record figures, and the NAO tables still use the original list. Cape May and Delaware Bay gauges are the next step.
Storms come from NOAA's Northeast Snowfall Impact Scale (NESIS) catalog as reproduced on Wikipedia. It uses Kocin and Uccellini values through 2003 and NCDC values after, starting with the 1956–57 winter and ending in 2021–22. ENSO phases come from the Oceanic Niño Index.
NESIS rates snowstorms only, and it weights population, so it misses rain-and-wind nor'easters and interior storms that skip the big cities. The catalog is more complete after 2004 and has some known gaps. The El Niño edge holds in both eras, but treat exact rates as approximate.
NAO and PNA values are CPC monthly indices. The NAO timing test uses month-to-month changes, with significance from shuffle tests against all Dec–Mar months, 1956–2022. Hurricane counts and ACE come from the NHC record via Wikipedia's season list. Correlations are Spearman rank with shuffle-test p-values. Atlantic phase boundaries follow the standard warm (to 1963), cool (about 1964–94), and warm (1995 on) dating.