Hurricanes are the greatest weather threat to Texas. 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 winds of 39-73 mph are expected within the watch area within 48 hours.
A Tropical Storm Warning is issued when winds of 39-73 mph are expected within the warning area within 36 hours.
A Hurricane Watch is issued when winds of 74 mph or higher are possible within the watch area within 48 hours. Hurricane Watches are issued 48 hours in advance of the anticipated onset of tropical-storm-force winds.
A Hurricane Warning is issued when winds of 74 mph or higher are expected within the warning area within 36 hours. Hurricane Warnings are issued 36 hours in advance of the anticipated onset of tropical-storm-force winds.
An Extreme Wind Warning is issued when a major (Category 3 or higher) hurricane with winds of 115 mph or higher are expected to begin within the warned area within an hour.
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.
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