Inside Report for Sept. 27, 2012

Homes with water lapping at the window sills are sad sights.

Watching people wade to National Guard trucks with a few possessions in garbage bags is even more wrenching.

Thousands of homes in Livingston, Tangipahoa and other parishes flooded because of Hurricane Isaac. Many occupants didn’t foresee their plight.

As a storm nears, people try to determine potential personal impacts.

Which tree might fall?

Where is the safest place to park the car?

Is evacuation necessary, or is it safe to stay at home with a stock of supplies?

Many people’s answers were wrong when Isaac roared into Livingston Parish.

From the back of a National Guard truck that plowed through water to take supplies to some residents and to rescue others, the miscalculations became painfully apparent.

Cars that had been moved to what longtime residents had always thought of as high ground had water up to the windshields.

People whose homes had never flooded sloshed to the trucks to flee the water.

Even to storm-seasoned residents of lower Livingston Parish, Isaac brought surprises.

Most storms do.

Before a storm arrives, most people in coastal Louisiana gather information through the media from hurricane prognosticators who predict hurricane paths, rainfall amounts, wind speeds and storm surges.

It’s valuable information, and experts have honed their predictions, but they still cannot tell people precisely what will happen.

They can give what they believe to be worst-case scenarios. Those projections may be accurate for some places in the wide area in which the storm might strike.

In places that don’t feel the storm’s brunt, people may have evacuated when it turns out they got minimal water or wind. That sometimes breeds complacency when the next storm approaches and warnings echo.

No matter what experts, public officials and individuals expect, storms bring surprises.

A slight shift in a projected hurricane track, hours before landfall, may mean one area is spared a strong storm surge and another area gets more water than expected.

Sometimes a hurricane’s forward speed slows as it bears down on the coast. A slow storm usually pushes more water in front of it than a similar storm that sprints to shore.

A storm that balks over an area might cause flash flooding with unexpected rain. A tree that falls in a drainage ditch may make flooding worse for a particular neighborhood.

Changes in a storm’s speed and track, even after it hits land, may cause unexpected heavy rain to the north of an area. That, in turn, might cause river flooding to the south a couple of days after the storm passes.

The class rating of a storm can be a poor predictor of flooding damage, since flooding involves factors other than wind speed.

Each hurricane is unique.

Hurricanes Gustav and Isaac both did heavy damage to Livingston Parish. Gustav mainly did it with wind. Isaac mainly did it with water.

As storms approach the coast, it’s wise for people to act as if they will take the worst hit.

Simply saying you survived a storm that looked similar or worse as it approached doesn’t mean the oncoming storm will produce similar results.

Smart hurricane planning and reaction for residents or emergency officials is to prepare for the worst, hope for the best and be ready to respond to the unexpected.

Bob Anderson is the chief of The Advocate’s Florida Parishes bureau. He can be reached at banderson@theadvocate.com.