Isaias strengthens into the first hurricane of the Atlantic season

BREAKING: Isaias strengthens into the first hurricane of the Atlantic season, on track to strike the US Gulf Coast later this week with heavy rains and potential flash flooding.

Isaias is now a hurricane, the first of the Atlantic season.

It strengthened overnight, and forecasters have it tracking toward the US Gulf Coast later this week. The headline threat isn't just wind, it's water. Heavy rain, and the kind of flash flooding that turns streets into rivers in under an hour. The National Hurricane Center is watching it closely, and so should anyone from Texas to the Florida panhandle.

The Gulf Coast knows this drill, but familiarity is exactly what gets people hurt. Flash flooding kills more Americans in these storms than the wind does, and it's the part people underestimate every single time. Cities like New Orleans sit low, drain slowly, and flood fast.

If you're in the path, the next two days are the ones that matter. Fuel up, stock up, and listen to local officials, because this thing arrives whether you're ready or not.

This is Sara White, reporting for HIT.