TEXAS CITY, Texas -- Hurricanes are the greatest weather threat to Texas, according to state and federal emergency management officials. Hurricane categories are based on the level of damage from hurricane winds. Here is how these dangerous storms form. Air over the ocean warms, picks up moisture and begins a circular motion. This forms a tropical depression, an area of low pressure that draws more air in from other areas.
When the wind speed increases above 39 mph, the tropical depression becomes a tropical storm and the storm is given a name. When the winds reach 74 mph, the storm becomes a hurricane.
A tropical storm watch is issued when storm-force winds are possible within 36 hours.
A tropical storm warning is issued when storm-force winds are expected within 24 hours.
A hurricane watch is issued when hurricane-force winds are possible within 36 hours.
A hurricane warning is issued when hurricane-force winds are expected within 24 hours.
When there's a major storm in the Gulf of Mexico, monitor broadcast media and listen for instructions from local officials. Do not take tropical storms for granted. Even slow moving tropical storms can be deadly.
FEMA Hurricane Preparedness Web page: www.fema.gov/hazard/hurricane/hu_season09.shtm
FEMA leads and supports the nation in a risk-based, comprehensive emergency management system of preparedness, protection, response, recovery, and mitigation, to reduce the loss of life and property and protect the nation from all hazards including natural disasters, acts of terrorism, and other man-made disasters.