by Scott Martin.

The forecast for the Grand Prix of Long Beach for IMSA and the NTT IndyCar Series really hasn't changed that much at all, with the exception of a slight nudging of the temperatures. Skies on each day will start off mainly cloudy, with some fog reducing visibilities during the morning. Eventually the fog will lift and clouds will dissipate as the noon hour approaches and skies will be partly cloudy to mostly sunny by the afternoon. Highs will top out in the lower to mid 70s. No rain is in the forecast.

by Scott Martin

This will be an easy forecast week for IMSA and IndyCar, as the weather will not be changing that much at all in Long Beach, California. Skies will start off cloudy on each day, with those clods dissipating throughout the day, becoming mostly clear by the afternoon hours. 8 am temperatures will start off in the mid 60s and reaching the mid to upper 70s by the late afternoon hours. Winds will be out of the west to southwest at 5-15 mph each day. That is really it... no rain, no snow, and no severe weather. Have a great time at the event.

By Doug Schneider

The main change to the forecast today has been to add a mention of a light sprinkle or shower on Sunday morning.

A west to northwest flow will bring the marine layer into the Monterey Peninsula each night, resulting in low clouds forming. These clouds will linger through the morning, and dissipate by noon, leaving mostly sunny skies on Friday and Saturday afternoons. On Sunday, the moisture will get a little deeper as a cold front approaches from the northwest. This could squeeze out a little rain, probably just a couple hundredths of an inch at most. Rain could fall during the Sunday morning warm-up session, but again, the light nature of the rain should not have much of an impact. For the race, it will be partly sunny with temperatures in the 60s.

By Doug Schneider

Aside from some clouds and fog each morning, nice weather is expected for IndyCar's visit to WeatherTech Raceway Laguna Seca. 

All this week, a large area of high pressure will be located off the California coastline. This high will produce a west to northwest flow off the Pacific Ocean. In this setup, it is common for the Monterey Peninsula to experience fog and low clouds overnight due to the marine layer - moist air off the ocean spreads inland, and as temperatures cool overnight, fog can form. This past weekend at the IMSA event, fog and low clouds formed each morning, and usually cleared out between 10 am and noon. I expect a similar pattern this weekend. Some of the early morning sessions may be impacted due to low visibility. ​Once the clouds and fog lift, sunny skies will prevail. Thanks to the cool air off the ocean, temperatures will only reach to around 70 degrees in the afternoons. 

By Scott Martin

Other than a few tweaks to the temperatures and dewpoints, the forecast remains the same for the Grand Prix of Portland. Both days will start off mostly cloudy, but clouds will decrease throughout each day and skies will become mostly clear by the afternoon hours. Highs will top out in the mid to upper 70s.

By Scott Martin

While there will be plenty of excitement on the track at Portland International Raceway, the weather department will be rather uneventful as the forecast is really similar for each day of the event weekend. Each day will feature a mix of sun and clouds, with temperatures starting off around 60 degrees in the morning and topping out in the lower to mid-70s. Winds will be out of the northwest ranging from 2-8 mph, and we'll remain dry throughout the weekend.

By Doug Schneider

Today, some scattered to isolated showers and thunderstorms will be possible in Middle Tennessee. There is only a slight chance of one of the showers passing over the downtown area, so I have the chance at 20% with a low impact. A dry day is more likely. With mostly cloudy skies today, temperatures will peak in the mid 80s.

More sunshine is expected Saturday and Sunday, which will bring afternoon temperatures into the 90s. With a high pressure ridge building over the area Saturday, showers are unlikely. 

I'll be a the race starting this afternoon, and I'll try to post weather updates on Twitter if necessary. Follow @RacecastWx. 

By Doug Schneider

I expect that the weather will cooperate for the inaugural Music City Grand Prix in Nashville, Tennessee. No rain is expected at this time, and although temperatures will be warm, the humidity won't be oppressively high. For Nashville in early August, it looks pretty good.

Through much of the middle portion of the week, there will be a broad upper level trough over the eastern U.S. with a few small troughs that ride around the larger trough. The main impact of this trough for Middle Tennessee will be to push the deep moisture east of the Appalachian Mountains, and keep temperatures fairly cool in Nashville. A secondary trough passage will occur on Friday, but there will be a lack of moisture that makes the chance of rain very low. Friday will have some partial cloud cover, and there is one model that generates some rain, but at this time I think a dry day is most likely. 

Nashville will be on the west side of the trough on Saturday, which will keep dry weather and mostly sunny skies in the forecast. With a high pressure ridge slowly building in, temperatures will trend upward into the lower 90s by Sunday. Humidity levels will be rising too, but dewpoints are expected to be in the upper 60s to near 70, which could be much worse for this time of year in Nashville. The normal high for Nashville this time of year is around 91, so we should see highs in that neighborhood. 

I'll be attending the race this weekend. As a resident of Tennessee, it's exciting to have a race in my home state!