Coca-Cola 600 Forecast
Unlike last year the Coca-Cola 600 should be mostly dry but I wouldn’t say the chance of rain is zero or we will have mostly clear skies either. There are a few things that will make me very cautious about a passing thunderstorm or shower especially this evening. The chances are very small but the ingredients we have for storms are there with lots of low level moisture & lots of instability. What we lack is a trigger to start updrafts going to get thunderstorms. There’s isn’t many of those around today but a few triggers may develop later today.
First of all we have had quite a bit of dense fog this morning over the Mid-Lands of South Carolina this will lead to some differential heating. Which just means some area get hotter quicker than other causing some convergence as the cooler spots surface air moves to the warmer spots as that air is lifted. Second we have numerous outflow boundaries from yesterdays storms to our south, these are subtle wind shifts lines put out from thunderstorms. Third we have some terrain effect but this would only be in the mountains & foothills.
The last ingredient is upper support as an upper low is just to our southwest over Alabama this is is causing the plume of tropical moisture to move into the upstate of South Carolina this morning. 
This upper low is also causing just a big of divergent flow aloft, which can help cause some lift. All of these ingredients are small and likely will not lead to widespread rain or storms but a 20-30% chance of a few storms cannot be ruled out. Below is the Bufkit sounding from the NAM model and it shows lots of cumulus clouds which is the red and green and then right around 8-9pm a few isolated thunderstorms popping up around Charlotte.
