Why Irene Was More Dangerous Than It Should Have Been
Storm dodged bullet, grew bigger, lasted longer, meteorologists say.
As Hurricane Irene passed over the Bahamas late last week, it encountered low atmospheric, or barometric, pressure, which causes air to rise—in this case, warm and moist air, the lifeblood of hurricanes.
Over the islands, Irene's peak winds reached 115 miles (185 kilometers), making it a Category 3 hurricane.
Forecasters last week had feared Irene would maintain those very high winds when it hit the U.S. mainland at North Carolina over the weekend.
But as the storm approached the state, Irene encountered a mass of dry, hurricane-squelching air coming off the coast. Irene soon slowed to Category 1 speeds, making landfall with winds of about 85 miles (137 kilometrs) an hour.
But the dry air also diffused Irene so that, though its winds had