By: Stephen McCoy

These are the updates we like to see in a forecast. With the cold front moving through, rainfall chances will be primarily overnight Friday into Saturday morning, with slightly cooler temperatures also on the way. However, as opposed to the previous forecast, once the front moves through, no more rainfall is expected for the remainder of the weekend. In fact, mostly clear to partly cloudy conditions will be present for much of Saturday and Sunday with some heavier cloud cover moving in during the afternoon to evening.

By Doug Schneider

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An approaching cold front will bring showers and thunderstorms to CTMP on Friday afternoon. The likely time frame for showers on Friday starts at 2 pm, but the majority of showers are expected to occur in the evening, after the end of on-track activity. 

The front will push through on Friday night, and rain will be gone by the time on-track activity starts on Saturday morning. As high pressure builds over the area, Saturday will be a beautiful day with mostly sunny skies and highs in the upper 70s F, or mid 20s C. Sunday looks much the same. Should be a great weekend to attend the race. 

By: Stephen McCoy

There will be a slow moving cold front moving through the region for the weekend, bringing chances for rainfall each day. The greatest chances are expected to occur on Friday into Saturday, ahead of the front. However, due to the speed of the frontal passage, rainfall chances along the front may continue into Sunday. Winds ahead of the front will bring warmer air to the region from the Southwest, causing highs in the upper 80's. Behind the front, winds will shift to the North/Northwest, causing slightly cooler conditions to move in for the remainder of the weekend.

All this being said, some aspects for the forecast may still change between now and the race weekend. While creating this, the ECMWF forecast model switched the greatest chance for rainfall from Saturday to Sunday; the  GFS and UK models still continue to show the rainfall on Friday/Saturday. We'll see how this plays out, but (hopefully) the outlook will be more concrete by the next forecast.

By Doug Schneider
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Sometimes making a forecast graphic is difficult to properly reflect what I think the weather will be. This graphic looks like there will be more rain at CTMP this weekend than I expect there to be, due to the uncertain timing of rain associated with a cold front.

A cold front will be moving across the upper Great Lakes on Friday. Showers and thunderstorms along and ahead of the front may be in the Lake Ontario area late Friday afternoon or evening. The final session on Friday is MPC qualifying from 5 pm to 5:45 pm, and it will be close as to whether it is affected by these storms. Right now, I'm putting the chance of rain before 5:45 pm at 30%. I think the bulk of rain will hold off until later in the evening or Friday night.

How quickly the front moves through on Friday night will affect the chance of rain on Saturday morning. I have a 20% chance of showers in the forecast for Saturday morning to account for the models that are slower with the front. However, it is possible that the rain with the front may be gone by the time the WeatherTech Championship practice starts at 8 am. Temperatures will be cooler on Saturday, with highs in the upper 70s.

Sunday looks like a beautiful day for racing. Drier air builds in behind the front, and I expect mostly sunny skies and temperatures in the mid 70s for the WeatherTech Championship race in the afternoon. 

By Doug Schneider

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The main change to today's forecast update is to add a small chance of showers on Thursday afternoon. Yesterday, I mentioned that showers and thunderstorms are likely on Wednesday night. That is still expected, but the low pressure system is trending slower, which will keep some moisture and instability over the Finger Lakes area into Thursday afternoon. I do not expect that this will be a heavy rain, and I don't expect lightning either, so impacts should be low. But since there are practice sessions on Thursday, and amount of rain may lead to a stoppage. 

High pressure builds over the area on Thursday night, and will shift east through Friday and Saturday. This will provide nice weather with plenty of sunshine and a warming trend to temperatures as a southerly flow develops. 

The high pressure ridge weakens on Sunday, and a cold front will approach from the west. The timing of this front still looks like it will be moving through on Sunday night. However, I can't rule out some isolated showers and thunderstorms popping up in the afternoon, ahead of the front. So I will keep the 20% chance of rain in the forecast, but I still think that most of the rain will arrive after the race ends, and impacts on the race are low. 

By Doug Schneider

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I'm happy to report that the weather looks great for this year's edition of the Sahlen's Six Hours of the Glen. The slight chance of rain on Sunday is uncertain, and it could hold off until after the race is over. More on that below.

On Wednesday and Wednesday night, there will be numerous showers and thunderstorms in the Finger Lakes region of New York as a cold front moves across the area. These showers should be gone by the time practice sessions start on Thursday morning. Temperatures will be very nice on Thursday, with highs in the mid 70s and comfortable humidity levels. 

Through Friday and Saturday, a large high pressure ridge will be moving across the region from west to east. This will provide mostly sunny skies both days, with temperatures warming into the lower to mid 80s as a southerly flow develops on the west side of the high. 

Sunday is the day with the most uncertainty, as there will be increasing instability and a low pressure trough approaching from the west. The question is the timing of this system - will showers hold off until after the race ends around 4:40 pm EDT? As of today, I think the most likely scenario is that the rain arrives after the race ends, so I have just a 20% chance in the forecast. This could change as we go through the week, so check back here for updates. 

By Scott Martin.

Friday will be a very hot and humid day at VIR. Skies will be partly to mostly sunny throughout the day, with only a very small chance of an isolated shower or thunderstorm during the afternoon hours. Chance of rain is only at 20%. Heat will be the biggest factor as the high is expected to top out around 94 degrees with the heat index of 101 degrees. Winds will be out of the west at 5-10 MPH. If a shower or storm is able to develop close by or at the track, winds may gust up to 20 mph.

Saturday will be a totally different day, as a cold front will have moved through the area, dropping those humidity levels into a more comfortable range. Skies will be sunny, and no rain is expected. The high will be around 84 degrees with winds becoming breezy by the afternoon. Winds will be out of the northwest at 5-10 mph with gusts up to 20 mph at times. Chance of rain is 0%.

Sunday will be another great day with low humidity and nice temperatures. Skies will be mostly sunny, and the afternoon high should top out around 82 degrees. Winds will be out of the north at 5-10 mph. Chance of rain is 0%.

By: Stephen McCoy

There's been a bit of a change to Saturday's conditions at Road America, though the rest of the forecast has remained mostly the same. The synoptic weather pattern is still expected as it was in the previous forecast for Thursday and Friday where a low pressure system will pass to the South of the region, moving towards the mid-Atlantic. The increased moisture in the mid levels on the North side of the system will bring a slight chance for light, isolated showers during the day. Surface winds from the Northwest will result in slightly cooler than average temperatures.

Where the forecast has changed is that a second low pressure system is now expected to form over Southwestern Canada on Friday, slowly moving eastward through the weekend. A warm front will be present, extending to the Southeast from the center of the low, and passing through the region from the West. Winds will shift to the Southwest, resulting in slightly warmer temperatures than Friday. A chance for more scattered showers is possible along the front, however timing looks to be closer to the afternoon to evening.

For Sunday, winds will shift back to the North/Northeast as high pressure builds in, resulting in more below average temperatures with partly cloudy conditions. Fog may be possible in the early morning, but will disperse after sunrise.