By JENNIFER KAY and GARY FINEOUT
Associated Press

MIAMI (AP) - A tropical weather system that rapidly strengthened into Hurricane Michael on Monday is likely to keep growing stronger ahead of an expected strike on Florida's Panhandle by midweek, forecasters said.

Michael could strengthen into a major hurricane with winds topping 111 mph (178 kph) by Tuesday night before an expected strike Wednesday on the Panhandle or Big Bend, according to the National Hurricane Center.

Since the storm will spend two to three days over the Gulf of Mexico, which has very warm water temperatures and favorable atmospheric conditions, "there is a real possibility that Michael will strengthen to a major hurricane before landfall," Robbie Berg, a hurricane specialist at the Miami-based storm forecasting hub, wrote in an advisory.

Michael's large size, strong winds and heavy rains could produce hazardous flooding along a stretch of Florida's Gulf coast with many rivers and estuaries where seawater pushed ashore by a hurricane could get trapped, said Hurricane Center Director Ken Graham.

"This is a part of the Gulf of Mexico that is incredibly vulnerable to storm surge," Graham said.

Parts of Florida's curvy Big Bend could see up to 12 feet (3.5 meters) of storm surge, while Michael also could dump up to a foot (30 centimeters) of rain over some Panhandle communities as it moves inland, forecasters said.

A large mound of sand in Tallahassee was whittled down to a small pile within hours as residents filled sandbags to prepare for potential flooding. A couple breweries in the city offered free filtered water to anyone bringing in growlers, jugs or other containers.

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