Florida on alert as Alberto on verge of hurricane

ST PETERSBURG, Fla., June 13 (Reuters) 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.

Anxious officials ordered thousands of residents to evacuate barrier islands, flood plains and trailer parks as the storm's maximum sustained winds accelerated to near (110 km per hour), just shy of the 74 mph (119 kph) threshold at which tropical storms become hurricanes.

''Just a little increase here of 8 km an hour would put it over the edge and make it a Category 1 hurricane,'' U.S. National Hurricane Center director Max Mayfield told CNN, referring to the five-step Saffir Simpson scale of hurricane intensity.

''It's not a major hurricane, in fact it's not even a hurricane yet, but it's strong enough to do some damage.'' Florida Gov. Jeb Bush declared a state of emergency even though the most likely area of landfall was sparsely populated swampland and farming country in Florida's ''Big Bend.'' The area has no big cities like New Orleans, which was devastated last August by Hurricane Katrina.

Florida officials said 26 shelters in 16 counties had been opened for evacuees.

''This is a serious storm and we are taking it seriously,'' said Bush. ''We're not dealing with large numbers of people. But given the storm surge we anticipate and given the velocity of these winds, I hope people aren't being defiant.'' EVACUATION ORDERS Around 21,000 people were affected by evacuation orders, local media reported. The emergency director in one rural area, Citrus County, was going door to door to urge people to move to higher ground.

The storm was about (200 km) south of Apalachicola, in Florida's panhandle, at 5 p.m. EDT (0230 HRS IST) according to a bulletin from the hurricane center. It was moving northeast at about 16 kph.

Energy traders said the path of the storm should take it too far east to cause disruptions or damage to offshore oil and gas platforms, which were battered during last year's record-breaking Atlantic hurricane season that had 28 tropical storms, of which 15 became hurricanes.

Experts have forecast a busier-than-average season this year as climatic conditions remain favorable for hurricanes.

Alberto's formation less than two weeks after the June 1 start of the season seemed to underscore the predictions.

Rain pelted down on Florida's west coast and the hurricane center said 10-20 cm were possible through Tuesday across parts of the state and Georgia.

Storm surge flooding up to 3 meters above normal tide levels was expected across much of the Gulf Coast.

While tropical storms pose little threat to developed countries, anxieties in U S coastal areas have been heightened following the flooding of New Orleans by Katrina -- the most costly and one of the most deadly U.S. natural disasters.

Katrina killed more than 1,300 people, caused 80 billion dollar in damage, helped sink President George W. Bush's popularity because of the fumbled federal emergency response, left tens of thousands homeless and helped lift oil prices to record highs.

Much of the U.S. Gulf Coast is still recovering.

Alberto formed on Sunday off Cuba, where there was some minor flooding but no deaths.

The cause of the hurricane activity of the past two years is the subject of fierce debate in the United States.

Hurricane experts believe the Atlantic is in a decades-long period of naturally heightened hurricane activity. But climatologists say there are indications that human-caused greenhouse gases may be increasing the intensity of hurricanes, which draw energy from warm water.

REUTERS AD VC0728