Bulletin text On the night of August NUMBER@1 , Katrina underwent another episode of rapid intensification , strengthening to a Category NUMBER@2 hurricane with maximum sustained winds of NUMBER@3 mph -LRB- NUMBER@4 km/h -RRB- by NUMBER@5 am CDT on August NUMBER@6 .

That night , the storm underwent another period of rapid strengthening , strengthening to a Category NUMBER@2 hurricane with maximum sustained winds of NUMBER@3 mph -LRB- NUMBER@4 km/h -RRB- by NUMBER@5 am CDT on August NUMBER@6 .
