Alberto, a pre-season subtropical storm, formed over the Northwestern Caribbean Sea Friday morning and will bring a wide swath of tropical moisture across the region as it moves northward in the Gulf of Mexico over the weekend.
Volusia County joined the entire southern half of Florida in a flood watch issued by the National Weather Service on Friday afternoon and additional flood watches are possible as Alberto moves northward.
In Volusia and Flagler counties, the wet blanket over Memorial Day weekend activities is forecast to bring up to four inches of rain through Wednesday, although even more rainfall is possible in some locations. The greatest chances of rain start Saturday night and stretch through Monday, and range from 50 to 80 percent. Daily highs over the weekend will be in the mid to low 80s, with overnight lows in the low 70s.
Even when it's not raining, it's going to "feel thick, heavy, humid and generally uncomfortable," wrote Angela Enyedi, a meteorologist with the Weather Service office in Jacksonville in a Friday afternoon forecast update.
Alberto is early; hurricane season doesn't start officially until June 1.
On Friday afternoon, the center of Alberto was meandering in the Caribbean about 85 miles south-southeast of Cozumel Mexico with sustained winds of 40 mph, the National Hurricane Center said. The storm was drifting eastward at about 2 mph.
But the storm's reach extends far to the north and east, over Cuba and South Florida. That's a typical trait of subtropical storms, which have maximum winds far from the center, rather than clustered tightly around the center like a tropical storm. Subtropical storms show some, but not all, of the characteristics of a tropical storm.
"Instead of having warmer temperatures throughout its core, like a tropical storm, its upper levels are still quite cool, like what you'd typically see with winter and spring low pressure systems," said Will Ulrich, a meteorologist with the Weather Service in Melbourne.
Alberto is forecast to move northward over the weekend, passing the western tip of Cuba on Saturday morning, then turning toward the northwest. By Sunday night, the center of Alberto is forecast to be be somewhere between Apalachee Bay and New Orleans.The Hurricane Center said gradual strengthening is forecast over the next 72 hours.
A tropical storm watch was issued Friday for the northern Gulf Coast from Indian Pass, Florida westward to the metropolitan New Orleans, as well as for Mexico, from popular cruise destination Tulum to Cabo Catoche. A storm surge watch was issued for the coast from from Horseshoe Beach in Florida's Big Bend west to the mouth of the Mississippi River.
Rainfall accumulations of 4 - 8 inches are forecast across portions of the Florida Keys, and south and southwest Florida, with up to 12 inches possible in some locations. The Hurricane Center stated Alberto could produce 10-15 inches of rain, with isolated amounts up to 25 inches, in the northeast portions of the Yucatan Peninsula and western Cuba.