Once we get into the month of May it feels like I’m constantly pushing out non-stop forecast updates…partly due to the amount of track activity, but mostly due to the always-evolving spring weather in Indiana. Let’s talk about the conditions expected for the IndyCar Grand Prix.

THE WEATHER: Here’s how the environment is setting up over the next couple days. There is a cold front that is expected to move through the area tomorrow. Ahead of this front, a moisture- laden south wind will help feed pre-frontal rainshowers, and an occasional thunderstorm, throughout the day on Thursday. Will there be any dry breaks? Sure…but overall, activity will be building through mid-day and afternoon before tapering off closer to evening. Bottom-line, Thursday can best be categorized as a wet and windy day. The front itself will pass through Indianapolis late Thursday, and there could be some brief light rain or drizzle early in the morning on Friday still lingering around. No significant impact. After that, skies will be clearing pretty rapidly as IMS will be on the backside of the cold front, and despite plenty of daytime sun, temperatures will run unseasonably cool, starting the in the 40s (!) and remaining in the low-60s. This continues into Saturday, but later in the afternoon is where things may get a little tricky.

Since my first long-range outlook I sent out earlier this week, forecast models have been consistent in keeping Saturday dry, with some rain moving in late, but only over the southern counties. That said, the trend in the last 24-hours has been to move that rain in sooner and further north…and it looks as though it could mean a few rainshowers creeping into central Indiana by early Saturday evening. This could come into play considering the late ‘green flag’ start time for the Grand Prix. For now it looks to be of the hit-or-miss variety, and not in significantly heavy amounts (until Saturday evening at least), but it does have the potential to make things interesting. How this scenario continues to trend will definitely warrant watching over the next couple days.

FOR FANS: Thursday is going to be wet for the Road to Indy-series testing. For Friday through Saturday, you’ll want to dress for 40s in the early mornings and very mild low-60s during the afternoon. If you’ve got a jacket that doubles as a raincoat, that should suffice to get you through Saturday for now….just in case.

FOR DRIVERS: Did I mention its going to rain Thursday? Not expecting very favorable conditions for the scheduled test day for USF 2000, Indy Pro 2000, and Indy Lights series. As we get into Friday, no major weather impacts to events are expected. Low ambient temperatures on Saturday morning may be an issue for morning sessions, with a possible delay until the combined ambient and track temps are within safe tire operating thresholds. Then there’s the potential showers late Saturday that could keep teams guessing on strategy…but its still a little early to know what real impact that may (or may not) have. We’ll have to keep an eye on that one. Wind direction will be switching around from northwesterly on Friday to easterly on Saturday, so there will be at least one variable that will change the environmental conditions between qualifying and racing.

LOOKING FURTHER AHEAD: Against my better judgement, I did take a peak at the general weather pattern setting-up in the coming weeks. After rain late Saturday-early Sunday, things look generally good until the next major system flows through around mid-week…then it looks pretty intriguing for qualifying weekend with high temps dipping below-norms and yet again stuck in the 60s. After that, stay tuned. The pattern seems to hint at above normal temps the following week leading up to the Memorial Day weekend…but that’s about all I can provide within reason at this point!

I’ll be posting daily weather updates to my twitter feed (@Indycar_wxman) leading up to the big show, so check-in daily for the latest! - IndyCar Weatherman