Simplifier

Okay, so you're seeing some extra snow hanging around the Great Lakes in the weather models, even after the main snowstorm has moved on. That's likely due to something called "lake-effect snow." Think of the Great Lakes as giant bathtubs of water. When cold air blows over these relatively warmer lakes, the air picks up a lot of moisture and heat. This warm, moist air then rises, cools, and forms clouds. If it's cold enough, those clouds will dump snow. The "lingering" snow you see is probably because the lake is still warmer than the air, so it keeps feeding moisture into the air, creating these smaller, localized snow showers even after the big storm is gone. It's like the lake is acting as a little snow-making machine!

Atmospheric Chemist

As an atmospheric chemist, I can offer some insight into the phenomenon you're observing, though it's primarily a meteorological effect. The Great Lakes, due to their large surface area, retain heat longer than the surrounding land, especially into the early winter. This temperature difference creates a localized instability in the atmosphere. When a cold air mass, laden with moisture from a passing weather system, moves over the relatively warmer lake, the lower layer of air is heated and picks up additional moisture through evaporation. This warm, moist air rises, cools, and condenses, leading to cloud formation and precipitation, often as lake-effect snow. The "lingering snowfall" you see is likely due to this localized, continuous moisture supply from the lake sustaining snowfall even after the initial weather system has moved on. The lake acts as a persistent source of moisture and heat, essentially "re-seeding" the atmosphere with the ingredients needed for snowfall. The shape and orientation of the lake, along with prevailing wind patterns, can further concentrate this effect, leading to localized and prolonged snowfall events downwind of the lake.

Geophysicist

The phenomenon you're observing is likely related to lake-effect snow. The Great Lakes, particularly during the colder months, retain a significant amount of heat relative to the surrounding landmasses. This temperature difference drives atmospheric instability. When cold, dry air masses pass over the warmer lake waters, the air is heated and picks up moisture through evaporation. This warm, moist air rises, cools, and condenses, forming clouds. If the air is cold enough, this condensation results in snowfall. The "lingering snowfall" you see is likely due to the continued evaporation and cloud formation over the lake, even after the initial, larger weather system has passed. The lake essentially acts as a localized source of moisture and heat, sustaining snowfall downwind.

Fluid Dynamics Expert

The phenomenon you're observing is likely related to lake-effect snow. The Great Lakes, particularly when their water temperature is significantly warmer than the overlying air, act as a moisture and heat source. This temperature difference creates instability in the lower atmosphere. As cold air masses pass over the warmer lake, the air is heated and picks up moisture through evaporation. This warmer, moister air rises, cools, and condenses, forming clouds. If the air is cold enough, this condensation results in snowfall. The "lingering snowfall" you observe is likely due to the localized enhancement of snowfall downwind of the lake, as the air continues to be modified by the lake's influence. The shape of the lake basin and the prevailing wind direction can also contribute to the persistence of this effect. Topographical features on the downwind side of the lake can further enhance snowfall by forcing the air to rise, leading to additional condensation and precipitation.

Meteorologist

Indeed, what you're observing in those precipitation models is likely the effect of lake-effect snow. It's a very real phenomenon, especially common downwind of the Great Lakes during the colder months. Here's the process: When cold, dry air masses move across the relatively warmer waters of the Great Lakes, the lower layer of air is warmed and gains moisture through evaporation. This warm, moist air rises, cools, and condenses, forming clouds. If the air aloft is cold enough, that condensation turns into snow. The prevailing winds then carry these snow clouds downwind, often resulting in intense, localized snowfall. The "lingering snowfall" you see is due to the continued evaporation and moisture pickup from the lake, sustaining the cloud formation even after the initial, larger system has passed. The shape of the lake basin and the surrounding topography can also play a role, causing convergence and further lifting of the air, which enhances snowfall. So, while the initial snowfall might be associated with a larger weather system, the lake's influence can create a persistent, localized snow band that appears to "stick" around the lake.

Points of agreement

• The "lingering snowfall" is likely due to lake-effect snow.
• The Great Lakes retain heat longer than the surrounding land, creating a temperature difference with passing cold air masses.
• This temperature difference causes the cold air to pick up moisture through evaporation, rise, cool, condense, and form clouds, leading to localized snowfall.

Points of disagreement

• The level of detail provided in the explanation varies. Some responses provide more specific details about atmospheric instability and the role of wind direction, while others offer a more simplified explanation.
• The emphasis on specific aspects of the phenomenon differs. Some responses focus more on the meteorological aspects, while others highlight the role of the lake as a heat and moisture source.