A satellite image of Tropical Storm Alberto, taken June 12, 2006. Tropical Storm Alberto was on the verge of becoming the first hurricane of 2006 on Monday after it unexpectedly gained power over the warm waters of the Gulf of Mexico and aimed at northwest Florida. (Xinhua/Reuters Photo)

    WASHINGTON, June 12 (Xinhua) -- Over 20,000 people were ordered to evacuate their homes along Florida's Gulf Coast as tropical storm Alberto threatens to come ashore Tuesday as this year's first Atlantic hurricane.

    The U.S. National Hurricane Center posted the hurricane warning on Monday as Alberto strengthened to a storm with maximum sustained wind of about 110 kilometers per hour during the morning.

    Forecasters said that the storm was centered about 150 kilometers south of Apalachicola, Flordia on Monday evening and could come ashore as a Category 1 hurricane in western Florida on Tuesday.

    Florida Governor Jeb Bush has declared a state of emergency and urged Florida residents to take serious precautions.

    The United States was hit by a record 15 hurricanes last year, with the worst one, Katrina, killing over 1,300 people and flooding the city of New Orleans. Enditem