Dangers of Hurricane Irene

08/25/2011 08:45 am ET | Updated Oct 25, 2011
  • Paul Yeager Meteorologist and Author of 'Weather Whys: Facts, Myths, and Oddities'

Irene is a large and powerful hurricane, and the dangers of the storm will be immense as it moves northward along the East Coast of the United States during the next few days.

Since only a slight shift in the forecast track -- say 200 miles, which is not a large error in the field of meteorology -- would mean a huge difference in the actual weather in a given location, I'm not going to focus on specific threats for specific areas as much as what the possible threats are in a more general sense.

It's not hype; it's what can happen if Irene makes a direct landfall or tracks very close to the coast.

Anyone with any type of interest (living, business, relatives, travel, etc.) along the East Coast needs to follow the details of the forecast closely. The best location for that, in my opinion, is the National Hurricane Center. This will provide the latest guidance from the nation's leading hurricane experts, and it will be more up-to-date than any news story, which is sometimes based on weather information from a previous National Hurricane Center advisory.

They update the forecast frequently, and you want to keep up with the latest information.

Devastating Damage

When we think of hurricane-related damage, the first thing we think of is a war-zone like array of damage, including flattened building, buildings without roofs, and boats piled into a heap. That type of damage is typically found very near where a major hurricane (Category 3 or higher) makes landfall of moves through.

Some of the damage is, of course, caused by the powerful wind, but much of it is caused by the storm surge. A storm surge is effectively a temporary rise in sea level caused by the hurricane pushing water ahead of it, similar to a wave created in a bathtub by a hand moving through the water. A storm surge can be 15 feet or more with a direct hit from with a major hurricane, destroying everything in its path and causing widespread flooding.

Since Irene is predicted to be a major hurricane from its passage through the Bahamas through its northward track until Irene is about as far north as North Carolina, this type of damage is a danger if Irene makes a direct landfall or passes over a region during this time.

At this point (again, the forecast details are critical), the eastern portion of North Carolina is the most likely location for this type of damage, where evacuations were underway on Wednesday.

Extensive Damage

A Category 2 hurricane, although not considered a major hurricane, is capable of producing extensive damage, including some structural damage (removed roofs, mobile home destruction, destruction of older/poorly built homes, flying debris, broken windows, etc.) near where the storm makes a direct landfall or passes over a region.

There is also the potential for a large storm surge, especially if the storm is large (not all hurricanes are the same size) and is moving fairly quickly.

Irene may very well still be a Category 2 storm when it makes a more direct hit in the Northeast, which seems likely, whether that be on Long Island and then southern New England or eastern New England.

Moderate Damage

Irene is expected to be a fairly large hurricane, so its wind and rain will extend beyond the areas that receive a direct hit from the storm. This includes the threat for flooding rain, downed trees, and power lines.

This threat will be exacerbated in areas where heavy rain has fallen in recent weeks since rivers and streams are less capable of handling the intense rain -- and because power lines and trees are more likely to be knocked over by wind when the ground is saturated than when it's dry.

Since a large portion of the highly populated corridor from the mid-Atlantic region to New England has had heavy rainfall in recent weeks (some areas have had close to 20 inches in the less than the past month), an indirect hit can still have very serious consequences.

Dangerous Seas/Rip Tides

A large hurricane will produce dangerous seas, including rip tides, well in advance of--and well behind -- its passage.

Beach goers, whether vacationers or storm chasers (not a good idea), from Florida to Maine need to be extremely careful when entering the water at any time from now through at least the weekend.

The ocean might look tempting, especially for East-Coast surfers who usually don't get to see large waves, but the unpredictable and strong tide can quickly whisk you out to sea.