THE NOVEMBER 2025 STORM

The most heavily instrumented reconstruction in the observatory: the November 11–13, 2025 severe storm, fit from particle precipitation and pinned to what satellites and ground cameras actually photographed — in both hemispheres.

What happened

On November 11–13, 2025, a severe geomagnetic storm drove the auroral oval deep into the mid-latitudes for two consecutive nights. Aurora was photographed across the northern United States — the observatory's validation set includes a photo-measured oval border at 44.3° magnetic latitude near the storm's peak — with the southern oval simultaneously active for the aurora australis community.

Why this reconstruction is special

The November 2025 scene is the observatory's most cross-checked build:

• POES particle precipitation — ~29,000 satellite passes' worth of measured electron flux fit the oval's position and intensity.
• VIIRS Day/Night Band imagery — 83 independent oval-boundary measurements extracted from nighttime satellite imagery, in both hemispheres, fused into the fit. Where the model says the aurora stood, a satellite photographed it standing.
• TREx all-sky cameras — a 144-frame ground-camera mosaic from five Canadian stations, viewable as a layer in the app, so you can compare the model to the real sky minute by minute.
• Real satellite drapes — VIIRS nighttime imagery of the aurora itself, draped at the exact times and places it was captured, north and south.

Every layer is honestly labeled in the app: measured data renders as measured, model output as model¹.

The storm nights

The November 2025 storm ran across the nights of November 11–13, with the first night the showpiece: the auroral oval drove deep into the mid-latitudes while North America sat under darkness, and photographs came in from latitudes that see aurora only a handful of times per decade. The observatory's reconstruction tracks the boundary continuously through that night — as Earth rotated, the midnight sector swept westward across Europe and then North America, and the satellite record follows it the whole way. The second night was the recovery act: still stormy, the oval still displaced equatorward, but contracting poleward hour by hour as the ring current relaxed.

A reconstruction with three independent witnesses

This storm became a proving ground for the observatory's multi-instrument method, because three completely independent data sources ended up agreeing on where the aurora was:

• Particle precipitation. The backbone of the scene: tens of thousands of measurements from the MetOp satellites' energetic-particle detectors as they crossed the auroral zones, fused into the oval's brightness, energy and structure through both nights — both hemispheres.
• Nighttime satellite imagery. The VIIRS Day/Night Band — the sensor that photographs city lights from orbit — imaged the aurora itself. Dozens of oval-boundary measurements were extracted from those images and fused into the fit, and because the imaging satellite crosses the equator near 1:30 am local time, it samples exactly the midnight sector the particle satellites miss. On the first night, the imaged boundary independently confirmed the storm's deepest equatorward reach.
• Ground cameras. All-sky cameras of the TREx network across western Canada recorded the display at five stations; their mosaic renders in the scene as a photographic truth layer, five minutes per frame, so you can compare the model against what the cameras actually saw.

Where the record has limits, the scene says so. The southern hemisphere's November nights are short and bright at auroral latitudes — polar summer — so southern optical coverage is thinner than the north's, and the reconstruction leans on the particle record there rather than pretending to imagery it doesn't have.

Why this storm matters going forward

The 2024 superstorms were reconstructed retrospectively, with methods developed after the fact. November 2025 was the first major storm reconstructed with the pipeline already standing — the fusion, validation gates and boundary-extraction methods all existed before the storm did. It is the template for how every future storm enters this archive: measured where instruments looked, honestly modeled between passes, and checked against photographs before anything ships.

Frequently asked questions

How strong was the November 2025 geomagnetic storm?

It was a severe (G4-class) storm² with two active nights, November 11–13, 2025, and mid-latitude aurora photographed down to a measured oval border of 44.3° magnetic latitude in the north.

What data is the November 2025 reconstruction built from?

POES particle precipitation fits the oval; 83 VIIRS Day/Night Band boundary measurements in both hemispheres and TREx all-sky camera mosaics validate it; VIIRS nighttime imagery is draped where satellites actually photographed the aurora.

Was the aurora australis visible during the November 2025 storm?

Yes — the southern oval was active both nights, and the reconstruction fits it from the same satellite data, including southern-hemisphere DNB boundary measurements. Stand under the southern sky in the replay.

Sources

Numbered references for the claims above.

1. The Observatory’s own reconstruction pipeline and validation gates are documented on data & methods.
2. NOAA Space Weather Prediction Center — NOAA Space Weather Scales (G-scale). swpc.noaa.gov
3. World Data Center for Geomagnetism, Kyoto — final/provisional Dst index. wdc.kugi.kyoto-u.ac.jp

More storms: Gannon May 2024 · October 2024 · Halloween 2003 · Carrington 1859

By The Space Weather Observatory · checked against the data & methods record · Updated August 21, 2026

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