By Jim Melwert

PHILADELPHIA (CBS) – The oldest and largest high school rowing regatta in the world, but all eyes on the forecast as the region is under a flash flood watch with 1-2 inches of rain in the forecast.

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Time trials start at 8 a.m., then semi-finals today and tomorrow, with finals tomorrow evening. But, Stotesbury Cup Regatta director Clete Graham says with the predicted rain, they may lose tomorrow all together.

“The hydrographic predictions on the National Weather Service website show the river going up to about nine feet, which would make it just about un-rowable.”

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Listen to Jim Melwert’s interview with Clete Graham in this CBS Philly podcast:

They will row in the rain, but lightning and high currents will force them off the river.

And if they lose tomorrow, there’s no time for a make-up, as the city championships, which were postponed due to the huge rains and flooding a couple weeks ago, are scheduled for Sunday.

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For updates on the event’s schedule, check the Stotesbury Cup Regatta’s website.