On March 1, 2021, NOAA satellites monitored lake-effect clouds flowing over Lake Superior. The satellites captured light snow bands embedded in the clouds.
Lake-effect snow occurs when very cold air moves over the warmer waters of a lake. This causes some lake water to evaporate into the air and warm it. This warmer, wetter air rises and cools as it moves away from the lake. As the air rises, clouds form that release that moisture to the ground. If it’s cold enough, the moisture falls as snow. This process can generate snowstorms that produce significant amounts of snowfall downwind.
The geostationary GOES-16 (GOES-East) satellite orbits 22,236 miles above Earth’s equator, at the same speed the Earth rotates. This means GOES-16 has a constant view of the same area, allowing the satellite to monitor cloud formation, view lake-effect clouds in motion, and track the convective bands within these clouds. The ability to track weather conditions as they happen aids real-time decision-making and short-term forecasts and warnings.
By combining information from multiple channels on GOES-16’s ABI instrument, meteorologists can distinguish snow and ice from clouds. In imagery using the day snow/cloud layers data product, ice and snow are seen as white, while clouds are yellow. This type of imagery is called RGB (red-green-blue) composite imagery. Learn how RGBs provide critical information to forecasters.
The NOAA-20 satellite, which orbits from pole to pole, flew over Michigan at 1:35 pm local time there, and its VIIRS instrument captured a stunning shot of the clouds streaming over the lake. Polar-orbiting satellites like NOAA-20 are positioned 512 miles above Earth’s surface, providing ultra-high resolution views. The two Joint Polar Satellite System (JPSS) satellites circle the globe 14 times a day, each imaging the entire Earth at least twice daily.
NOAA satellites like the geostationary GOES-16 and GOES-17 and the polar-orbiting NOAA-20 and NOAA/NASA Suomi-NPP, work together to provide critical information about clouds for weather forecasts and warnings.