Saturday...first moderate accumulation of the season?

On Friday, a strong cold front will move through the area. Ahead of this cold front, heavy rain and embedded thunderstorms will occur all day Friday, and into Friday Night. Behind this cold front, temperatures will quickly fall. These falling temperatures, combined with a low pressure system forming over NW Ohio or SE Ontario and then strengthening as it moves Northeast, will likely allow for some moderate snow accumulation to occur on Saturday Night. The forecast models are still in disagreement about the track of this low pressure system, which could lead to changes in its strength and location, which in turn would lead to different snow accumulation forecasts. However, one forecast model, the NAM has been relatively consistent, and that is therefore what I am mainly basing my forecasts off of. The NAM shows a surface low forming in Ontario, and moving to the Northeast while strengthening. Snow would wrap behind this low and impact us starting late Saturday afternoon and ending in the wee hours of Sunday Morning.

Chance of Snow: 70%

Reasoning: If the surface low takes a track too far to the east, we would likely see no snow at all. Otherwise, we will see a period of at least light to moderate snow, perhaps heavy at times.

Chance of a Snow Day: 0%

Reasoning: The accumulations won't be anything major, and the timing of the system (Saturday Night) is poor for a snow day to occur.

Predicted Accumulation: 1-4 inches

Reasoning: At this time, the low pressure system's track would support several hours of moderate snowfall. However, this prediction is likely to change somewhat. If the low tracks further to the east than forecast, or much further west than forecast, we probably will see less than 1" of snow. Conversely, if surface low formation occurs earlier than expected, and then the low strengthens more than expected before reaching us, we could see more snow than forecast. So, check back here tomorrow morning when I will issue my update on this system.

Here is my preliminary snowfall map for SE Michigan: