While snow is coming Thursday, the sky will be sunny to mostly sunny this afternoon. A 10:15am cloud snapshot of the Ohio Valley shows some clouds to the northwest moving southeast:

Despite sunshine, it is still cold. As of noon, temperatures are in the mid to upper 20s for most:

A sustained wind between 10 and 20mph means it feels colder. Wind chills in the Tri-State are in the teens and 20s:

Temperature will barely rise this afternoon thank to a westerly wind dragging cold air in from the Plains and Mississippi:

The influence of low pressure will begin tonight in the form of high- and mid-level clouds increasing. Plan for temperatures fall through the 20s:

Snow is likely Thursday. The coverage will increase in the morning, be steady for most of the afternoon, and end Thursday evening:

Temperatures in the low to mid 20s will mean snow-to-liquid ratios will be higher than usual. This means that liquid-equivalent precipitation (all forms of precipitation melted down) will need to be multiplied by a factor that is higher than usual. A baseline ratio for temperatures in the upper 20s and low 30s is 10:1. Given that temperatures will be in the low to mid 20s, this snow-to-liquid ratio is more like 18:1. Remember, 10:1 or 18:1 are snow-to-liquid ratios, NOT forecast snow totals. I am explaining the meteorology of taking what forecast models produce to a snow forecast. Models are producing 0.1″ to 0.18″ of liquid for this event (all snow), so totals of 2-4″ totals look appropriate for most, but not all. Here’s what I’m thinking for event total snowfall (Thursday and Thursday night):

This is a significant increase in amounts compared to 24 hours ago. This will not be a winter storm, per se…but it will be significant winter weather event. Roads will at least be wet on Thursday, and they will likely be snowy in spots with pavement temperatures in the 20s. Snow squalls are unlikely tomorrow, but the visibility will be reduced by snow…especially in the late morning and first half of the afternoon Thursday:

Red lights for travel conditions are somewhat rare for me. Again, this does not appear to be a winter storm, but impacts will be significant!

Scattered showers are forecast through the lunch hour. Regional radar shows rain showers moving from west to east through the Tri-State:

Notice the break in showers over west-central Indiana. That break is over the Tri-State by mid-afternoon, but the area of rain showers in Illinois will overspread the Tri-State late in the business day and this evening. The amount of lift in the atmosphere is increasing to the west, so plan for more showers later today and tonight after a brief break this afternoon.

It’s warm outside! As of 11am, temperatures are in the 50s:

Temperatures will be gradually falling through the 50s this afternoon with showers favored early and late:

Showers will continue this evening as temperatures fall through the 40s:

Showers will diminish late tonight, briefly mixing with flurries, especially northwest of Cincinnati:

Notice the quicker fall in temperatures late tonight compared to this evening! We’ll start Wednesday in the upper 20s and low 30s. Little if any warm up is forecast Wednesday, even with decreasing clouds:

Wednesday will be a much colder and breezy day. The next wave of precipitation (Thursday) will be in the form of snow showers. Models are getting more aggressive with the strength of this wave, so up to 1″ of snow is forecast Thursday:

Notice that no Tri-State community is favored for more or less snow. Snow showers implies snow that starts and stops. Here is a summary of late week impacts:

Snow showers will increase in coverage Thursday morning, decrease in coverage late Thursday, and cold air will plunge into the Ohio Valley behind this wave. Lows will be in the low to mid teens and highs will be in the mid to upper 20s Friday through Sunday.

Snow squalls are unlikely Thursday, but there will be drops in visiblity underneath snow showers.