By: Stephen McCoy

The weather setup for this weekend's races at Mid-Ohio are not looking too favorable in the initial forecast. Mostly cloudy for the better portion of the event with chances for rainfall each day. Couple that with high dew point temperatures  will make for muggy conditions for at least part of the weekend.

Entering the weekend, the mid Ohio region will be located between two major synoptic systems. A low pressure system is expected to be centered over Ontario, Canada with an area of high pressure located over the Southeastern United States. The anticyclonic rotation around the high will wrap moisture from the Gulf of Mexico through the southern Great Plains and into the Midwest, where the steering flow will be partially influenced by both pressure systems. A similar pattern will extend into the mid and upper levels of the atmosphere, resulting in plenty of cloud cover over the region.

For Friday, conditions will start mostly cloudy with a chance for showers as a surface trough approaches the region from the West, extending from the low pressure system over Ontario. Conditions will begin to clear for the late morning and early afternoon, which will cause temperatures to warm into the mid 80's for a high. The added moisture to the region will mean dew point temperatures will reach the mid 70's, resulting in heat index values in the mid 90's for the afternoon. Cloud cover will increase during the afternoon and evening as scattered thunderstorms may develop.

The aforementioned synoptic pattern is expected to continue into Saturday, resulting in mostly cloudy conditions through the day with heat index values in the low 90's. Scattered thunderstorms are possible again in the afternoon, which may have major impacts for the on-track sessions. Similar conditions may be present on Sunday, but with slightly cooler temperatures as winds shift to the West.

By: Stephen McCoy

For the weekend, an upper level high pressure ridge will be located over much of the northern Midwest, maintaining dry conditions aloft. For Friday, a surface high pressure system will extend southwest from central Canada into the Great Lakes region. The anti-cyclonic flow around the pressure system will result in winds over eastern Wisconsin largely from the northeast, bringing below-normal temperatures to the region. As with the upper levels, dry air will be persistent in the lower levels, resulting in clear conditions throughout the day.

Saturday will start much like Friday with minimal cloud cover, but with temperatures beginning to return to normal as the surface high pressure breaks down over the region. With no steering factor, surface winds will be relatively calm; a low pressure system approaching the region from the south on Sunday will cause winds to gradually shift to the southeast. Much like Friday, no rainfall is expected as dry air remains over the area.

As previously mentioned, a low pressure system over the southern plains will make an approach towards the Midwest on Sunday, shifting winds to the southeast. A local high pressure system will also develop over the northern Great Lakes, which will intensify surface winds from Saturday; gusts during the day could reach 20 mph. Minor cloud cover may move in for the afternoon in the low and mid levels as the pressure system moves towards the region. Rainfall is unlikely during Sunday's race, though some isolated showers may be possible during the evening.

By Doug Schneider

Apologies for getting this forecast posted later than usual; real life commitments can sometime get in the way of our hobby.

The weather looks great for the Detroit Grand Prix weekend. A large high pressure system will be slowly drifting west across the Great Lakes region, which will provide dry conditions throughout the event. The temperature will get very warm on Friday and Saturday, into the lower 90s. But a cold front is expected to pass through the area from the north on Saturday night, which will bring cooler temperatures on Sunday. No rain is expected with the frontal passage. Winds will be fairly light through the weekend, less than 10 mph, and generally from the northeast.

By Doug Schneider

The weather continues to look great for the 107th Indianapolis 500. The main changes from the previous forecast are a slight increase in cloud cover Saturday and Sunday, and a slightly lower high temperature forecast for Sunday.

The pattern across the Great Lakes and Ohio Valley region will be a large high pressure area over the Great Lakes, with a low pressure system over the Southeast states. Through the weekend, the low over the Southeast will drift toward the northwest, but the strength of the high will keep it far enough away from Indiana that rain will not be a concern at the Speedway. However, it will bring some increasing cloud cover, starting Saturday afternoon. This will be mainly midlevel and high level clouds, which will produce a milky sunshine - maybe just enough to take the edge off of full sunshine. 

Carb Day will be a little breezy, with a northeast wind between 10 and 15 mph, but Legends Day and Race Day will have lighter winds, between 5 and 10 mph. 

I'm glad that I picked a year with great weather to be attending the Indy 500 in person. This will be my second Indy 500; my first was in 2014 when Hunter-Reay and Helio had an amazing duel in the closing laps. I expect that this year's edition will be just as thrilling! 

By Doug Schneider

The weather for the 107th running of the Indianapolis 500 is expected to be beautiful. The models are in agreement that there will be a large high pressure ridge over the Great Lakes region through the end of the week, which will provide dry conditions and plenty of sunshine for all the festivities leading up to the race. Carb Day will have the coolest temperatures in the 70s and a northeast wind between 5 and 15 mph. As the high pressure area shifts to the east through the weekend, winds will shift to a more southerly direction and cause temperatures on race day to rise into the lower 80s, with a slight increase in clouds.

Check back through the week for updates.

By Doug Schneider

The timing of rain has come into better focus today. Confidence is increasing that Friday afternoon and evening will be the period when showers and thunderstorms move over the Speedway ahead of a cold front. I expect that the morning and early afternoon hours of Friday will be rain-free, partly sunny, breezy, and warm. The earliest potential timing for showers and storms to arrive will be around 2 pm, with the most likely timing being between 4 pm and 8 pm. So there should be plenty of running time in advance of the showers. 

Once the cold front moves through Friday night, the weather will be ideal for qualifying on Saturday and Sunday. Temperatures will be pleasant, with highs in the 70s, and low humidity. Saturday will be a little breezy, with a north wind between 10 and 20 mph. 

I hope the weather for the race will be as nice as the weather for qualifying! I'll have my forecast for the race posted on Monday.

By Doug Schneider

After a wet start to the week, the weather should be quite nice for most of practice and qualifying at IMS. 

A low pressure system is expected to track across Kentucky on Tuesday, spreading rain across central and southern Indiana through the day. At this time, the morning hours will have the best chance of rain, with a possibility of the rain ending during the afternoon. If it ends early enough, there may be time of dry the track and get a little practice in late in the afternoon, but I'm not optimistic that there will be any running on Tuesday. 

High pressure over the Great Lakes will be building over the area on Wednesday, providing sunny skies and fairly cool temperatures in the 60s to near 70 in the afternoon. Thursday will be nice as well, with a chilly start to the day followed by sunshine and highs in the 70s. 

Friday and Saturday are rather uncertain at this time. The models are showing a cold front moving through, but they do not agree on the timing. The chance of rain could be anytime between noon on Friday and noon on Saturday. Although the forecast has a chance of rain and a low impact both days, rain will probably affect the Speedway on only one of those days. It is possible that the front and the showers could move through Friday night, with no impact on the sessions. That is the best case scenario. As we get closer to the weekend, I'll have a forecast update with a better estimate on the timing of the front.

Sunday looks great with mostly sunny skies and highs in the 70s.

By Doug Schneider

The weather pattern across Indiana remains quite moist for the end of this week, with rain likely to impact the GMR Grand Prix.

Friday continues to have a high chance of showers, with thunderstorms possible at times. An upper level disturbance will be moving over the area, and in a moist environment, there will be numerous showers throughout the day. Picking out a time for showers is tough, because they could happen at any time, but the early to middle afternoon hours appear to be the most likely period for rain. Around a quarter inch of rain is likely on Friday, with up to a half inch possible if a stronger storm crosses the Speedway.

Saturday looks better as the upper level disturbance will move away, and a weak high pressure ridge will build in. There will still be a lot of moisture in the atmosphere, so with afternoon heating, some scattered showers and storms could pop up. But I expect that the chance of one hitting the Speedway is low. The race is more likely to have dry conditions than wet conditions, but we'll have to keep an eye on the radar and see what develops.