An estimated 16 to 24 inches of rain flooded Mississippi’s Pearl River County on Halloween night

Late on Halloween night, Oct. 31, an estimated 16 to 24 inches of rain fell on Pearl River County, Mississippi, a county about 60 miles north-northeast of New Orleans. The eight-inch spread in that estimate shows how difficult a downpour of that size is to pin down while it is still unfolding.

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Water reached waist depth inside a house near the community of Crossroads.

Crossroads, a high-water rescue and a washed-out road

Jonathan Erdman, a senior meteorologist at weather.com, summarized the local damage in a Nov. 3 weather explainer that opened with the Southwest and Florida and then circled back to the Gulf Coast. Flooding in Pearl River County reached waist-deep in a home near Crossroads, prompted at least one high-water rescue, and washed out a road. Erdman’s account does not name the road, the family or the agency that carried out the rescue, and it gives no count of homes affected, so the ground-level picture rests on those three details.

For scale, even the low end of the estimate is more than the 11.51 inches that set a daily record in Melbourne, Florida, two days later, and the high end is roughly double it. A rainfall estimate rather than a measured total is typical for a storm that overwhelms the observing network. Gauges can overflow or lose power, and forecasters then lean on radar-derived amounts, which carry the wide range seen here. The county lies on the Louisiana line along the Pearl River, so water that fell there drains toward a river system that also borders the New Orleans suburbs.

Kenner and Metairie at four inches an hour

Earlier that same evening, rain of up to 4 inches per hour flooded intersections and trapped vehicles in Kenner and Metairie, two suburbs west of New Orleans in Jefferson Parish, Louisiana. An hourly rate of that size can outrun storm drains built for ordinary heavy rain, because water arrives faster than pipes and pumps can carry it off. Erdman gave no totals for the Louisiana side of the line, and no injuries were mentioned in the recap. Simple arithmetic shows why the hourly figure matters: four hours at that rate would add up to 16 inches, the bottom of the Mississippi estimate, though the recap does not say how long the heaviest rain lasted at either location.

The two areas together outline a corridor of intense rain along the Mississippi and Louisiana Gulf Coast on a Saturday night, hundreds of miles from the Southwest flooding that would dominate the next two days of coverage.

A Halloween flood in a stretch of wet records

Pearl River County was an early stop in a run of unusual wet weather. In the Southwest, the Associated Press reported that Arizona, Colorado, New Mexico, Utah and Nevada took more than 20 trillion gallons of rain in two weeks, by one former NOAA scientist’s count, and within days Florida’s Space Coast saw flash flood emergencies. Mississippi’s night of rain fits that run as a less publicized chapter, with a flooding total that was estimated rather than recorded and a damage list that remains short in the available reporting.

Weather.com’s Erdman presents the sequence as a possible preview of a wet winter under a soon-to-be record-strong El Niño, whose typical pattern waters the South across a band running from California and Arizona east to the Gulf Coast states.

El Niño’s wetter South and what NOAA says about it

NOAA’s Climate Prediction Center reported in its Oct. 26 ENSO update that the Niño 3.4 region of the tropical Pacific ran 2.5 degrees Celsius above average, with the El Niño Advisory still in effect. The center’s forecast forum page gives better than an 83 percent chance of a strong-to-very-strong event through January-March 2027, and says such an event makes El Niño-consistent impacts more likely, though never guaranteed. The Gulf Coast sits inside the region where that wetter pattern normally shows up.

The Inertia, an environment and surf outlet, reported in August that NOAA was already raising its odds of a historic event during the summer months, a trajectory that matches the 83 percent figure for October through December now posted by the center. Pearl River County’s flood does not prove anything about that forecast on its own, since Gulf Coast deluges also happen in neutral years, and forecasters treat each such night as one data point. Nov. 12, the date of the next scheduled ENSO discussion from the center, will show whether the historic-event odds hold.

The unresolved piece is the final tally. Weather.com’s explainer cites an estimate of 16 to 24 inches rather than a gauge reading, and it reports no official measurement, damage figure or injury count for the county, so the best available description of the flood is still a range. Until the weather service or the county publishes measured totals, the 16-to-24-inch figure is best read as an informed approximation, and any damage comparison with other Gulf Coast floods will have to wait for those numbers.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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