By Doug Schneider

The season opener for GT World Challenge at VIR may be affected by some showers and thunderstorms, particularly on Saturday, but the vast majority of the racing action should be completed in dry conditions. 

A low pressure system is expected to be moving northeast across South Carolina and eastern North Carolina on Thursday. Even though it's just a couple days away, there are some big differences between the models in their placement of this low, and how much rain it brings to VIR. I'm going to be optimistic with my forecast, and only have a 30% chance of afternoon showers and thunderstorms. This is how most of the models are leaning, but the NAM shows much greater shower coverage. Hopefully it's an outlier. 

On Friday the low pressure system will be moving up the East Coast, and will no longer affect southern Virginia. With a lack of any significant high or low pressure systems in the area, I expect that Friday will be a typical summer day, with a few isolated showers or a thunderstorm possible in the afternoon, and a high around 90 degrees. 

Saturday appears to have the best chance of rain as an upper level trough and a surface cold front approach from the west. This system will provide lift and instability that will favor the development of showers and thunderstorms, mainly in the afternoon. There is a little uncertainty about the timing of the trough passage, and if it comes earlier there could be some morning showers as well. But the afternoon will be the more likely timing. 

Drier air aloft will build across the area behind this system, and which should result in a dry and mostly sunny day on Sunday. It will still be rather hot, with a high around 90.

By Scott Martin.

The NTT Indycar Series along with the USF2000 and IndyPro 2000 makes a trip to Road America for the REV Group Grand Prix weekend.

USF2000 & Indy Pro 2000 (Thursday & Friday)
An active pattern looks to bring a good chance of rain and thunderstorms mainly during the afternoon and early evening hours on Thursday for testing and practice sessions for both series. Temperatures will start off around 80 degrees and warm to around 89 degrees for the daytime high. Winds will be out of the southwest to south at 5-10 MPH. Rain chances will start off around 40% early but will max out at 70% by the early afternoon and persist through the end of the racing day.

Rain may hold off for most of the day on Friday until the late afternoon hours before the end of the racing day. I'm still going to include a very small chance of rain early but those odds will max out around 30% during the afternoon hours. Winds will be out of the west at 5-10 MPH. Temperatures will start of around 75 degrees and will warm up to around 85 degrees by the afternoon.

NTT Indycar Series (Saturday & Sunday)
Whether you would like to see the fastest racers in the world drive in the dry or in the wet, it looks like the dry-weather fans may win out this weekend. Saturday and Sunday will feature a great deal of sunshine early on, but convective clouds will slowly build during the late morning and early afternoon hours. There will be a very small chance of a passing shower or thunderstorms, but those will not be very likely. Saturday's temperatures will start off around 82 degrees for the first session and top out around 83 degrees during the afternoon. Sunday's temperatures will be around 76 degrees for qualifying and topping out around 80 degrees by the afternoon. Chance of rain on both days is barely at 20%.

By Doug Schneider

Showers and thunderstorms are likely in the Daytona area on Friday and Saturday afternoon and evening, which may have an impact on the IMSA WeatherTech240. Not much has changed in the expected weather pattern since my initial forecast on Monday. There will be a slow-moving low pressure system across the Deep South with a weak front near northern Florida. Since Daytona will be on the southern side of this system, hot and humid conditions can be expected during the event. Not too surprising for Daytona in July.

The chance of rain has increased a little on Friday as it looks like the front will be closer to Daytona than the models previously showed. Highs will reach the lower 90s, with a heat index around 100. Afternoon showers and thunderstorms are expected to develop in the area, and any of them could produce a brief heavy downpour. The only on track activity on Friday is a practice session from 6:15 to 7:15 pm, which is during the time frame when storms are possible. If a storm passes over the Speedway, a quick quarter to half inch of rain will be possible, along with gusty winds and frequent lightning. 

Saturday looks pretty similar to Friday, although there may be a little more cloud cover to hold temperatures down a little bit, but it will still reach 90 degrees. Like Friday, numerous showers and thunderstorms will develop in the afternoon and linger into the evening. Heavy downpours, gusty winds, and lightning are possible with any storms that pass over the Speedway. 

If you're at the track, stay weather aware and have a plan to find sturdy shelter before storms reach the Speedway. 

By Scott Martin

​Well, the good news for the GMR Grand Prix at the Indianapolis Motor Speedway looks to be dry throughout the entire race weekend, but the bad news will be the heat.

Friday looks to be a hot day with plenty of sunshine and only a few clouds, and winds will be too light to really give any help to cooling anyone off. Temperatures will start off around 84 degrees at 11:00 am, just before the first round of practice and heat up to around 91 degrees by 4:00 pm. It will only drop a degree or two for qualifying. Winds will be out of the northeast at 2-6 MPH.

​A near carbon copy forecast for Saturday but there will be just a few more clouds in the sky. However, skies will be mostly sunny and temperatures will be hot once again. At 9:00 am for the morning warmup, we are looking at temperatures around 77 degrees, but race temperatures will be around 87 at the drop of the green flag and will be hotter around 90 degrees for the checkered flag. Wind will be light once again out of the north-northeast at 2-6 MPH.

By Doug Schneider

The IMSA season resumes this weekend where it left off in January, at Daytona International Speedway. Unfortunately, it does not look like the weather will cooperate for the race. The weather pattern across the United States will feature a large trough over the east coast, and a large ridge over the Plains. As a result of this pattern, a front will be pushing south across the Southeast states on Friday, and stall across northern Florida on Saturday. This front will be the focus for showers and thunderstorms.

Friday at Daytona will be a hot and humid day. Most of the day will be rain-free with scattered clouds, then as daytime heating increases in the afternoon, scattered showers and thunderstorms will pop up in the area. Since the wind will be from the southwest, the sea breeze won't push inland enough to help cool temperatures, and highs will be in the lower to mid 90s. The practice session scheduled for 6:15  to 7:15 pm may have to deal with showers and thunderstorms in the area. I'd put the chance of rain during this time frame at 40%. 

The approaching front is expected to stall somewhere across northern Florida on Saturday, The exact position is uncertain this far out, but right now it looks like it will remain north of Daytona. This will keep hot and muggy conditions at the Speedway for race day, as drier air remains north of the front. The front will also provide lift that will enhance the chance of showers and thunderstorms. Timing is too uncertain to be specific at this time, and showers and thunderstorms will be possible at any time during the day. I put the impact at Moderate for now, but it is possible that could be raised to High with later forecasts, depending on how much rain is expected to fall. That will come into better focus through the week, so stay tuned for updates.