By Scott Martin - ​@RaceWx4You

It now looks like the remnants of Harvey will be pushed away from the area before it has a chance to rain on the Indycar weekend at Watkins Glen. Therefore, nice weather can be expected throughout the weekend. Mostly sunny to sunny skies can be expected each day, with highs starting off in the mid-60s on Friday and warming into the upper 70s by Sunday. No rainfall is expected on any day, so Firestone can keep those rain tires in the hauler.

By Doug Schneider - @Race4caster

There hasn't been a big change in what I'm thinking the weather will be in Mexico City this weekend for the WEC event, but my confidence is rising that the racing will be impacted by rain each day. A low pressure system will be taking shape in the Gulf of Mexico, just off the east coast of Mexico. This will produce an easterly flow through the low and mid levels of the atmosphere that will pump moisture toward the track all weekend, but especially Saturday and Sunday. With mountains all around the city, the moisture rising up the mountains slopes will produce showers and thunderstorms each day, and mainly in the afternoon hours. I've raised the chance of rain with the forecast update to reflect my higher confidence, and I've raised the Impact to High, as I think there's a good chance of the rain being heavy enough at times to require a stoppage in the action. Rain amounts are likely to be between a quarter and a half inch each day, but amounts could be higher than that if a storm moves directly over the track. 

The Weather Channel has a pretty good interactive radar display for Mexico here -
​ ​https://weather.com/weather/radar/interactive/l/19.43,-99.13

By Doug Schneider - @Race4caster

The remnants of Hurricane Harvey will be pulling out of Texas by Thursday, and high pressure will build over the state behind it. The high pressure system will bring drier and and stable conditions. This should provide nice weather for Pirelli World Challenge at COTA this weekend. Temperatures will be close to normal for Austin this time of year, with highs in the lower 90s and lows around 70. With a lot of sunshine each day and very little shade at the track, it will be important to stay hydrated and to use sunscreen. 

As the high pressure system over the Plains shifts to the east near the Mississippi River on Sunday, winds near and just above the surface will shift to a more easterly direction. This will transport a little more moisture inland on Sunday, which is why I have a slight chance of showers and thunderstorms in the forecast. I think that most of the activity will stay closer to the Texas coast, well east of COTA, but there is some uncertainty about how far inland storms may develop this far out in the forecast. There is just a very low chance that the racing could be impacted by storms. I'll be keeping an eye on this through the week, so check back here for updates and follow me on Twitter - @Race4caster.

By Doug Schneider - @Race4caster

It looks like the WEC weekend in Mexico City could be a wet one, as there's a good chance of showers and thunderstorms each day at the track. The weather pattern doesn't change very much through the weekend, as there will be a good amount of moisture in the atmosphere. There may be a slightly better chance of rain on Saturday as a low pressure system in the midlevels of the atmosphere develops, producing an stronger easterly flow of moist air off the Gulf of Mexico. But for the most part, the showers and storms will be driven by afternoon instability. It is possible that a heavy shower could stop racing action, but rain amounts are too uncertain this far out to put the Impact rating any higher than Moderate. 

I'll keep an eye on how the models change as we get closer to the event, and I'll post an update when any changes are needed.

By Scott Martin - ​@RaceWx4You