As George says, when things go wrong, they can go quite wrong: both rain and shift in wind direction. Fortunately, that is rare. We have never had a problem. I have seen planes take off when the runway is damp. The weather forecast this week calls for a lot of rain, so it could be an issue. Are you on an early or later flight? I would keep an eye on FlightAware to see how other flights are doing, then ask American to change your flights if there is disruption.
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