A cold front will be near the area tonight, and push south of the track on Thursday. The proximity of this front to the track and the presence of an upper level low pressure system will mean that showers are likely again on Thursday. Most of the rainfall is expected to come in the afternoon and evening. For Thursday, another quarter inch of rain will be possible.
Friday continues to be the day that is most questionable as the weather pattern will be transitioning. The upper level low pressure system will be slow to exit the area, and there will still be quite a bit of low level moisture. This is not a pattern that tends to produce heavy rain. In fact, there may only be a trace of rain or around a hundredth of an inch of rain. This is why I only have a 20% chance of measurable rain. I want to emphasize that the majority of Friday is likely to be dry, and I don't expect that what little rain there is will have much impact. It will be cloudy and fairly cool all day, with high in the upper 60s.
Clouds will be around for most of the day on Saturday, but I do expect that there will be some sunshine to break through the clouds, mainly in the afternoon. The upper level low pressure system should take all the rain east of the area, across the Carolinas. I expect that the race will be dry from start to finish. I do have to mention that the GFS model continues to show a high chance of rain on Saturday. Other models show a low chance. In my experience, the GFS tends to produce too much rain in this type of weather pattern, so I'm leaning toward the drier models. I think there will be too much dry air moving in and not enough lift in the atmosphere to produce measurable rainfall. Temperatures will continue to be a little cool, with highs in the upper 60s, and temperatures by the end of the race around 60.
We'll have our radar link ready to go at the top of the website later today.