GOES IR and GeoColor Satellite Imagery Explained

GOES IR and GeoColor Satellite Imagery ExplainedHow to read GOES-19 IR (Band 13 cloud-top temperature) and GeoColor satellite imagery — overshooting tops, cold-U / V signatures, what cold cloud tops mean for severe storm intensity.GOES-19 is the East-coast geostationary satellite. The Advanced Baseline Imager (ABI) on board has 16 channels — different wavelengths revealing different things. We surface two of them on the Charts tab in addition to water vapor: GeoColor (the "looks like the planet" picture) and IR (the cloud-top temperature picture that works at night).GeoColorA composite product designed to look like a true-color photo during the day. After dark it shifts to a "city lights" base map with the IR cloud overlay tinted blue. Visually intuitive — you can see snow cover, vegetation, smoke plumes, and (at night) urban lights. Best for general situational awareness.IR (Band 13, 10.3 µm)Measures the temperature of cloud tops. The colder the cloud top, the higher it is — and the higher it is, the stronger the updraft producing it. NWS and SPC color-enhance this channel so cold tops (severe storm anvils) jump out.

Gray / white: Warm cloud tops — low clouds, fog, stratus. Often nuisance fog or marine layer.

Light yellow: Mid-level cloud tops — typical thunderstorm tops.

Orange: Cold tops (around -50°C) — strong thunderstorm.

Red / pink: Very cold tops (below -60°C) — severe / supercell territory.

White / black (deepest): Extreme cold tops (below -75°C) — overshooting tops, often severe weather producers.

What spotters look for

Overshooting tops: Small bumps above the anvil where the updraft punches through the tropopause. Indicates a very strong updraft. Often coincides with severe weather at the surface.

Cold-U / V signature: A V-shaped pattern of warm air downwind of the overshooting top — sign of a mature supercell with a strong updraft.

Anvil expansion rate: Anvils expanding rapidly = strong, organized convection. Slow = weakening.

Convective initiation: First small cumulus puffs in clear air on visible / GeoColor often precede storm development by 30–60 minutes — useful for chasing.

Source: NESDIS GOES-19 at star.nesdis.noaa.gov. Updates every 5 minutes; full disk + sector views available.Part of the BloomWX learn library — beginner-friendly explainers covering every surface of the BloomWX weather dashboard. Open BloomWX to see live data for any U.S. county.