Does a GOES or Meteosat dot prove a ground strike?

No. The satellite observations include lightning within clouds as well as towards the ground. A dot does not identify a confirmed ground impact.

Are all ground-network reports ground strikes?

No. Ground networks can also report lightning within clouds. FMI reports may include a cloud or ground classification; read the available report details.

Can I find which building was hit on a satellite lightning map?

A public satellite lightning map cannot verify an impact on a specific building. Its observed flash location and spatial resolution do not provide building-level evidence.

By Boltwatch · 5 October 2026

Satellite Lightning vs Ground Strikes: What a Dot Means

A lightning dot can represent different kinds of observation. Satellites detect light from lightning, including flashes inside clouds. Ground networks listen for electromagnetic signals. Knowing the source helps you understand why a map cannot treat every dot as a confirmed impact on the ground.

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Lightning can stay inside a cloud

Lightning is an electrical discharge. It can happen within one cloud, between clouds, or between a cloud and the ground. Thunder accompanies the rapid heating of air along the lightning channel. Seeing a bright flash or hearing thunder does not by itself tell you whether something on the ground was struck.

A flash can also contain more than one stroke. A count of flashes and a count of strokes are therefore different measurements. When you compare two lightning maps, first check their definitions and the selected time interval. Matching the same town on both screens is not enough to make their counts comparable.

FMI: lightning, flashes and strokes explained

What GOES and Meteosat observe

NOAA's Geostationary Lightning Mapper and EUMETSAT's Lightning Imager observe brief light pulses from above the atmosphere. Their total-lightning observations include cloud flashes and lightning towards the ground. Boltwatch uses GOES over the Americas and adjacent oceans, and Meteosat over Europe, Africa and surrounding regions.

A satellite flash location describes observed light. It is not a verified ground contact point. Lightning can extend across a cloud, and illuminated cloud tops do not provide the same information as a sensor measuring a ground stroke. A marker near a road therefore cannot establish that the road, a nearby house or a particular tree was hit.

What a ground network adds

Ground networks estimate lightning positions from signals received by sensors at several locations. FMI provides observations from the Nordic and Baltic region. Its network uses sensors across Finland, Norway, Sweden, Estonia, Latvia and Lithuania. Boltwatch's FMI reports can include peak current and a cloud or ground classification where supplied.

A ground-network location is still an estimate. Network geometry and the characteristics of the signal affect the result. A cloud classification also means that ground-based equipment can report activity within clouds; ground network does not mean every report is a ground strike. Check the report's available details rather than inferring its type from the source name alone.

Why locations and counts differ

NOAA lists GOES GLM pixels at roughly 8 km across near the centre of its view and 14 km near the edge. These describe the instrument's spatial resolution, not a promise that a ground strike lies within that distance of a dot. Zooming in on a map enlarges the marker without improving the source measurement.

Sources observe different signals, group observations differently and arrive at different times. One storm can consequently produce different counts or nearby marker positions in satellite and ground-network views. Treat those differences as a reason to inspect source and time information. They do not automatically establish that one feed is broken or that the larger count is more accurate.

Use the source to answer the right question

To follow where a storm is electrically active, inspect recent reports and their ages. To investigate damage at one property, a public satellite map cannot provide proof of an impact. It lacks the building-level evidence needed for that conclusion. Read any ground-network details with their own location and classification limits.

Delivery also matters: GOES usually reaches Boltwatch about a minute after detection, while Meteosat arrives in ten-minute batches plus delivery time. Parts of Asia and Oceania lie outside Boltwatch's current coverage. An empty area does not confirm that lightning is absent. If you hear thunder, go indoors and follow official weather advice.

Frequently asked questions

Does a GOES or Meteosat dot prove a ground strike?: No. The satellite observations include lightning within clouds as well as towards the ground. A dot does not identify a confirmed ground impact.
Are all ground-network reports ground strikes?: No. Ground networks can also report lightning within clouds. FMI reports may include a cloud or ground classification; read the available report details.
Can I find which building was hit on a satellite lightning map?: A public satellite lightning map cannot verify an impact on a specific building. Its observed flash location and spatial resolution do not provide building-level evidence.