"Sometimes they exaggerate," said Carasia, 84, of Jeannette.

Then the rain came, and the nearby creek crept across the street and into her yard, toppling the wall she built as a little girl with her father and 11 siblings.

Carasia`s skepticism about weather warnings isn`t uncommon.

A third of those polled for a study by Federal Signal Corp. said they have to actually see a tornado, flood or other danger to care about the emergency. Less than half of the survey`s respondents said they would take steps to get to safety based on a severe weather warning.

Federal Signal Corp. is an Illinois-based manufacturer of public safety communications equipment.

"It`s concerning. Some people need to see a funnel cloud barreling in the distance (before they act)," said Fred McMullen of the National Weather Service in Moon, who monitors regional weather patterns with sophisticated 3-D maps on giant computer and television screens.

That was the case on May 22, 2011, in Joplin, Mo., when a tornado killed 158 people.

Tornado sirens rang out to warn people about the approach of the monster storm. But many ignored the alarms, according to a report by the National Oceanic and Atmospheric Administration. Residents indicated the sirens, common in the Midwest but not in the East, sounded so often that people had become "desensitized or complacent."

"The problem is convincing people," said Dennis Mileti, professor emeritus of the Natural Hazards Center at the University of Colorado, Boulder. "People simply go through life thinking they`re safe."

At times, even seeing danger isn`t enough -- as is the case with people who attempt to drive through flooded areas despite the obvious danger, he said.

Two tornadoes have swept through Western Pennsylvania in two years, the worst causing more than $4.5 million in damage in Hempfield and Sewickley townships in March 2011.

Many people were at work and were unable to hear television or radio alerts about the late-day storm.

Emergency responders said it was a miracle no one was killed by the twister`s 120-mph winds, which leveled nine homes and damaged 85 others.

With those memories fresh, people heeded warnings about a funnel cloud that swept through the Ligonier area last month, damaging more than 75 homes, said Westmoreland County emergency management spokesman Dan Stevens.

"They did go to safe areas in their homes. This is why we probably didn`t have people injured," he said.

To keep Pennsylvanians informed of looming weather disasters, the state rolled out an emergency notification system that sends alerts to email accounts, cellphones and pagers about public safety concerns.

But only 45,469 people, or about 3 percent of the state`s population, subscribe to the system, which has dispatched more than 27 million alerts since it began in November 2009, according to a state spokesman.

"Why would you subscribe to a service for things (you don`t think) are going to happen to you?" Mileti said.