Louisiana's governor has declared a state of emergency as Tropical Storm Debby threatens to flood low-lying coastal areas.

Gov. Bobby Jindal issued the declaration on Sunday.

Declaring a state of emergency is a primarily bureaucratic move that makes it easier for state officials to send needed supplies and workers to disaster-stricken areas.

Debby was moving very slowly out over the Gulf of Mexico, and it already had dumped heavy rain on parts of Florida.

It was not completely clear when or where Debby would make landfall, though current models showed it reaching hurricane strength by the time it hit the Louisiana coastline.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

A tropical storm warning was issued Sunday for Alabama to the Florida Panhandle as Debby lashed parts of the Gulf Coast with wind and rain.

The National Hurricane Center in Miami said Sunday morning that Debby was about 190 miles (310 km) east-southeast of the mouth of the Mississippi River. It said the storm warning has now been issued from the Mississippi-Alabama border eastward to the Suwanee River in north Florida.

Debby's top sustained winds had increased to about 60 mph (95 kph). The storm was moving toward the northeast at 6 mph (9 kph).

Although a forecast track was still uncertain, the hurricane center said people from Texas to Florida should remain alert to Debby's movement.

At least one tornado linked to the storm touched down Saturday in southwest Florida, but no injuries were reported. Heavy squalls pounded parts of that state. However, despite warnings in the Panhandle, Debby hadn't totally dampened vacations.

Thousands of people were on the beach at Pensacola Beach, Fla., on Sunday morning. Many used their phones to take photos of huge waves crashing into the concrete supports of a fishing pier. There wasn't any rain yet; just gusty winds and dark, fast-moving clouds.

Few people were in the water. Red flags warned tourists to stay out of the surf, and lifeguards cruised the sand on all-terrain vehicles, blowing whistles at anyone who got near the waves.

Workers with rental companies used pickup trucks to gather chairs and umbrellas as a precaution against an unusually high tide.

Forecasters said Debby could reach hurricane strength sometime over the next few days. Meanwhile, up to 10 inches of rain were possible along the coast, with isolated amounts possibly reaching 15 inches.

It was the first time four tropical storms have been recorded before July 1 during the Atlantic hurricane season since record keeping began in 1851. Alberto was the first storm this year. It formed off the South Carolina coast on May 19, almost two weeks before the hurricane season officially began June 1.

Debby forced the suspension of 8 percent of the region's oil and gas production.

The government reported that nine production platforms and one drilling rig were evacuated. The suspended crude production amounts to about 2 percent of U.S production and about 0.1 percent of global production. The reduced production is not expected to impact oil prices unless the storm strengthens and forces more production platforms to close.

A tropical storm warning was also in effect for part of the southeast Louisiana coast. Officials there have been monitoring the weather closely for the past several days. Some low-lying areas close to the coast flood easily in rough weather.

Near the mouth of the Mississippi southeast of New Orleans, Plaquemines Parish President Billy Nungesser said officials were making preparations to protect the main highway from tidal flooding.

A tornado touched down in Collier County in southwest Florida and forecasters warned other twisters were possible.

Several homes were damaged and tree limbs were down, smashing atop at least two cars, The Naples Daily News reported.

"This is quite common with this type of storm," senior hurricane specialist Stacy Stewart with the National Hurricane Center said of the twisters. "They tend to not be very large or long-lived, which can be difficult to detect on radar. So people need to keep an eye on the sky."

Out in the Gulf, Anadarko Petroleum removed all non-essential personnel and expected to close four facilities in the central and eastern Gulf. Chevron, Royal Dutch Shell and Marathon Oil said non-essential personnel were being removed but production was not being affected. ExxonMobil reported that its operations were unaffected.