By Doug Schneider

High pressure over the Pennsylvania and upstate New York areas will provide nice weather as practice sessions begin on Thursday at Watkins Glen International. That should continue for most of Friday as well, but there are some models that are developing some pop-up showers late in the day. I'm not very confident that this will happen or have any impact on the racing, so I'm keeping the rain icon out of the graphic for now. The chance of rain during the day on Friday is less than 20%. 

On Saturday a cold front will be approaching the area from the north, which will bring a better chance of showers. The timing is too uncertain to pinpoint this far out, but the coverage of showers appears to be scattered at this time, so I do not expect it to be a persistent all-day rain - passing on/off showers are more likely. The impact on the racing should be low, which means that all scheduled events should be able to be completed. 

The front should be through the area by Sunday morning, but there will still be an upper level trough over the region. Under this trough, there could be some light showers in the Watkins Glen area, but most of the activity should stay to the east, near Albany. I'm uncertain enough about the location of the showers that I am putting in a 20% chance of rain, but I don't think it will have an impact. Temperatures will be cooler and winds will be stronger on Sunday. 

​Check back through the week for updates to the forecast.

By Doug Schneider

I wanted to get a quick update on the weather situation this morning and what can be expected at Belle Isle Park this afternoon. It appears likely that there will be weather impacts during the racing this afternoon, especially the IndyCar race. 

Here's what's happening this morning on radar across the Great Lakes:

Low pressure is located over Wisconsin, with a stationary from stretching east across central Michigan. Showers are tracking E-SE along this front. For the morning hours, the shower and thunderstorm activity will stay to the north of Detroit, near the front.

Through the day, the low pressure area will track along the front, and the front will start to drift to the south. This will start to bring the showers and storms closer to Belle Isle in the afternoon. In addition, there will be a good amount of instability developing with daytime heating - it will be partly to mostly sunny for much of the morning and early afternoon. This instability will result in more showers and thunderstorms developing near the front the low pressure center, and some of these storms could become strong. 

Here is one model's (HRRR) depiction of what the radar will look like and where the low pressure center will be at 5 pm this afternoon:

Here's what I'm expecting at Belle Isle today - there may be a light and brief passing shower at any time during the day, but the chance of one is very low - maybe 20% or less. Then after 3 pm, the chance of showers and thunderstorms will start to rise (about 60%), with storms most likely to arrive sometime between 4 pm and 6 pm. The storms are expected to produce frequent lightning and heavy downpours. They may also be capable of producing gusty winds and hail. 

With the IndyCar race being run from 3:40 to 5:45 pm, it is likely that the race will be impacted. The extent of the impact will depend on how much rain falls, which can be highly variable depending on whether a storm tracks directly over the track or just skirts by. I do think that there will be lightning in the area, which will require a stoppage of the race. 

If you are going to Belle Isle today, stay aware of any storms that are approaching and take action when any calls to find shelter are announced. Have a plan ahead of time to get to a sturdy shelter. 

By Doug Schneider

The forecast graphic for the Detroit Grand Prix hasn't changed much from Wednesday, but there are some details on the timing of rain chances on Saturday that are coming into better focus today. More details on that below.

Today continues to look like a beautiful day at Belle Isle Park. There will be abundant sunshine and warm temperatures in the mid 70s. Admission is free today so get out and enjoy some great racing in perfect weather.

A cold front will be approaching Belle Isle from the north on Saturday, which will bring a chance of showers and thunderstorms. There could be showers in the area as early as the pre-sunrise hours of Saturday morning, but if these did occur they would be light and just wet the track a little. Scattered showers will be possible through the morning, but the chance of rain will be rising through the afternoon and evening, as will the threat of thunderstorms. This means that the IndyCar race, which is scheduled from 3:50 pm to 5:45 pm, will have the best chance of rain of Saturday's races. The exact timing of rain is too uncertain to say whether the race will be wet or dry at this time, but I would put the chance of at least part of the race being run in wet conditions at 40%. It is possible that rain could hold off until after the racing ends for the day, and I would put the chance of that happening at 60%. 

With thunderstorms being possible on Saturday, fans at the track should stay weather aware, and have a plan to find shelter, preferably in a building, when thunder is heard.

Showers and thunderstorms are likely after sunset Saturday evening as the cold front moves through. High pressure will build in from the north on Sunday, providing cooler temperatures and low humidity. It will be a beautiful day to take in a race, with mostly sunny skies and highs in the mid 60s. It will be a little breezy, with a north wind at 10 to 15 mph.

By Doug Schneider

The main change to the forecast for the Detroit Grand Prix with today's update is to shift the timing of rain chances on Saturday a little earlier. This could have the potential of impacting some races on Saturday, but which races will be impacted is still uncertain as there is not good model agreement on timing. 

Friday continues to look great as a cold front will move through the area on Thursday and a dry and cool air mass will follow it. With plenty of sunshine, highs on Friday will be in the lower 70s. 

Another low pressure system and its associated cold front will approach the area on Saturday. One model, the GFS, brings this front through on Saturday morning, which would put the chance of rain mainly in the morning and leave a dry afternoon. However, two other models that I have more confidence in, the NAM and ECMWF, have their rain chances with the cold front coming in the afternoon and evening. I think this later timing is more likely to occur than the earlier timing, but I can't rule out showers at any time of the day. With the afternoon timing of the cold front, there may be more instability available for thunderstorms, so I've added that to the forecast. This does not appear to be a rain-out situation at all - just scattered showers and possibly a thunderstorm in the area for a brief period, so I have the Impact as low. Even if a storms passes over Belle Isle, it should only produce around a tenth of an inch of rain. 

Behind the cold front on Sunday, there will be mostly sunny skies, low humidity, and cooler temperatures. Morning lows will be in the lower 50s, with highs in the upper 60s. 

By Doug Schneider

Overall, the weather looks really nice for the Detroit Grand Prix weekend. Don't let that rain chance on Saturday keep you away. With Trans Am, IMSA, and IndyCar in action, it should be a great event to attend. 

As teams set up at Belle Isle on Thursday, there will be rain in the area. A cold front will be pushing through the area, and while the heaviest rain will be to the south across Ohio, up to a quarter inch of rain may fall at Belle Isle on Thursday. 

Once the front exits Thursday night, a cool and dry air mass will build in from the north. Friday will be a beautiful day for racing, with sunshine and high temperatures in the lower 70s. Even better, Friday is Comerica Bank Free Prix Day, with no charge for admission. Free racing and nice weather - it doesn't get any better!

Saturday will have more cloud cover, but still a fair amount of sunshine, mainly in the morning. A southwest wind at 10 to 15 mph will raise temperatures into the mid 70s in the afternoon. Clouds will be increasing through the day as another cold front approaches from the north. However, at this time I expect that any rain with the front will hold off until after the racing is done for the day (the IndyCar race ends at 6 pm). There is a concert after the race which may have a chance of being impacted, but at this time I only have a 30% chance of rain during the daylight hours. Rain is most likely to arrive overnight. 

The cold front should be through the area by the time on track action starts on Sunday morning at 10:45. There is a chance of the timing changing with later forecasts, but for now I'm going with a dry and mostly sunny day. Winds will shift to the north behind the front, with temperatures topping out around 70.