Weather watches and warnings and when to worry

Even though 2011 broke all records for federally declared disasters, fewer than half of Americans polled in a recent survey would take action based on a severe weather warning and one-third would react only after experiencing property damage or injury. The survey, conducted by Zogby International for the Federal Signal Corporation, revealed that many Americans are so complacent about emergencies and natural disasters that they don't even know if their local community has an alert system.

With so many severe floods, tornadoes, hurricanes and wildfires occurring last year, you might assume people would be better prepared. "The fact that people could receive a warning that wouldn't motivate them to action is extremely concerning, particularly with 99 FEMA major disaster declarations issued last year alone," said Joe Wilson, a group president at Federal Signal.

But the lingo for weather warnings can be confusing. Is a watch more or less urgent than a warning? Should you heed an advisory? In general, a warning is more serious than a watch and means you have less time to prepare for the coming event or to evacuate. An advisory conveys less urgency but you should still pay attention. Here are guidelines from the National Oceanic and Atmospheric Administration, Ready.gov and the American Red Cross.

Hurricanes and tropical storms
Tropical storm watch. Tropical storm conditions (sustained winds of 39 to 73 mph) are possible within 48 hours.
Tropical storm warning. Tropical storm conditions are expected within 36 hours.
Hurricane watch. Because hurricane preparedness activities become difficult once winds reach tropical storm force (sustained winds of 74 mph or higher) a hurricane watch is issued 48 hours in advance of the anticipated onset of tropical-storm-force winds.
Hurricane warning. Hurricane conditions are expected within 36 hours.

Tornadoes
Tornado watch. Tornadoes are possible. Remain alert for approaching storms. Watch the sky and stay tuned to NOAA Weather Radio, commercial radio or television for information.
Tornado warning. A tornado has been sighted or indicated by weather radar. Take shelter immediately.

Heat waves
Excessive heat outlooks. Issued when the potential exists for an excessive heat event in the next 3 to 7 days.
Excessive heat watches. Issued when conditions are favorable for an excessive heat event in the next 12 to 48 hours. A watch is used when the risk of a heat wave has increased, but its occurrence and timing is still uncertain.
Excessive heat warnings/advisories. Issued when an excessive heat event is expected in the next 36 hours. A heat wave is imminent, or has a very high probability of occurring. The warning is used for conditions posing a threat to life or property. An advisory is for less serious conditions that cause significant discomfort or inconvenience and, if caution is not taken, could lead to a threat to life and/or property.

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