Tropical storm warnings were issued Saturday for areas along Florida's west coast and the northern Gulf Coast, as forecasters expect Subtropical Storm Alberto to strengthen as it churns north over the eastern Gulf of Mexico. The storm is forecast to approach the Gulf Coast on Monday, although heavy rain and tropical storm conditions will likely be felt well before Alberto arrives.
In a 11 p.m. advisory, the National Hurricane Center said the storm would continue to dump heavy rain on South Florida, which remains under a flood watch through Sunday. Rainfall accumulations of 3 to 7 inches with maximum of 10 inches are possible across the Florida Keys and southern Florida, according to the advisory.
The hurricane center issued storm warnings for the west coast of the Florida Peninsula from Bonita Beach to the Anclote River and for the northern Gulf Coast from the Aucilla River west toward the Mississippi-Alabama border.
As state authorities issued warnings of possible flooding and storm surge, Gov. Rick Scott declared a state of emergency for all of Florida's 67 counties Saturday morning.
Forecasters said that South Florida would continue to see heavy rain through Monday, with about three to seven inches of rainfall accumulations possible across the Florida Keys and South and Southwest Florida.
Potential impacts include minor tree damage that could lead to isolated power outages, flooding of low-lying areas and isolated tornadoes through Sunday, according to the National Weather Service in Miami.
Rain chances for South Florida are now at 80 percent Saturday night and Sunday afternoon. Conditions are expected to improve Sunday night and Memorial Day Monday — if 70 percent rain chance is considered an improvement over Saturday night and Sunday afternoon.
National Hurricane Center Director Ken Graham conducted a Facebook Live update at 11 a.m. Saturday and said it was time for residents along the Gulf Coast to prepare.
That generally means: Make sure you have your hurricane supplies on hand and cars gassed up. Even if this isn't a hurricane, it's a good test run for the season that begins Friday.
Though "pretty disorganized and tough to forecast" at the time of the update, Graham predicted Alberto's "swath of clouds and rain" could reach the southern tip of Florida Sunday night and the northern Gulf Coast of Mexico at 8 a.m. Monday.
Expected storm surges along the Florida to Louisiana coast could swell two to four feet, with some areas getting as low as a foot but some topping three feet.
Cedar Key, an island city off the northwest coast at Florida's big bend, is an area of particular concern at this time, Graham said. High tide arrives there Sunday afternoon, coinciding with the effects of the "sloppy" Alberto. These factors could lead to flooding.
A tropical storm watch is in effect for Tampa even though the city is not in the forecast cone, Graham said in his advisory.
"Don't focus on the track so much off the center," Graham stressed. "The rains are across Florida. Focus on the hazards."
In its 11 p.m. advisory, the National Hurricane Center said Alberto, the first-named storm of the 2018 season — which technically begins June 1 and ends Nov. 30 — had its center located about 120 miles west-southwest of the Dry Tortugas and 400 miles south of Apalachicola, Florida. The subtropical storm, which is forecast to move over the eastern Gulf of Mexico Saturday night through Sunday night and approach the northern Florida Gulf coast late Monday, is moving north at 13 mph — 8 mph faster than it had been on Friday night — with sustained 40 mph winds.
The weekend Memorial Day barbecue and your summer-opening dip in the ocean isn't looking too good. The service warns of a high risk of rip currents for beaches along the Florida coast.
Waterspouts are possible across all waters near South Florida through Monday, forecasters said. Atlantic winds could reach 23 to 28 mph with a max of 34 mph.
Conditions are favorable for Alberto to develop into a tropical storm since shearing winds are expected to ease by Sunday, which would concentrate thunderstorms closer to Alberto's low-pressure circulation and warm its core. A dome of high pressure is expected to slow Alberto down as it approaches the northern Gulf Coast late Sunday and early Monday.
Landfall, if Alberto cobbles all the necessary elements, is not expected until late Monday or early Tuesday somewhere between Tallahassee and New Orleans.