Subtropical Storm Alberto moving slightly east over Caribbean Sea with 40 mph winds

Tess Sheets | Treasure Coast Newspapers

UPDATES

8:05 p.m.: Subtropical Storm Alberto continued moving erratically east in the Caribbean Sea while maintaining wind speeds reaching 40 mph, according to the 8 p.m. advisory from the National Hurricane Center.

Location: 195 miles south-southwest of western tip of Cuba

Maximum sustained winds: 40 mph

Movement: East at 2 mph

At 8 p.m., the storm was moving erratically toward the east near 2 mph. A slow and erratic motion toward the north is expected Friday night. From Saturday afternoon into Sunday, a general northward motion at a faster forward speed is expected, followed by a turn toward the northwest on Monday.

Maximum sustained winds are near 40 mph with higher gusts. Gradual strengthening is forecast during the next 48 hours, with little change in strength forecast on Monday.

5:10 p.m.: Subtropical Storm Alberto was heading slowly east over the northwest Caribbean Sea with maximum sustained winds still at 40 mph, according to the 5 p.m. advisory from the National Hurricane Center.

Location: 85 miles south-southeast of Cozumel, Mexico

Maximum sustained winds: 40 mph

Movement: East at 2 mph

A storm surge watch has been issued for portions of the northern Gulf Coast of the United States from Horseshoe Beach, Florida, westward to the Mouth of the Mississippi River.

More: Subtropical Storm Alberto to bring rain over Memorial Day weekend

A Tropical Storm Watch has been issued for portions of the northern Gulf Coast of the United States from Indian Pass, Florida, westward to Grand Isle, Louisiana, including Lake Pontchartrain, Lake Maurepas and metropolitan New Orleans.

A slow and erratic motion toward the north is expected tonight. From Saturday afternoon into Sunday, a general northward motion at a faster forward speed is expected, followed by a turn toward the northwest on Monday. Maximum sustained winds are near 40 mph with higher gusts.

Gradual strengthening is forecast during the next 48 hours, with little change in strength forecast on Monday.

2:30 p.m.: What's the difference between a subtropical and tropical storm? When it comes to wind speed and impact, nothing. It only depends on where the storm pulls its energy and where the strongest winds are.

More: What's the difference between subtropical and tropical storms?

1:30 p.m.: Subtropical Storm Alberto is meandering over the northwest Caribbean Sea with maximum sustained winds of 40 mph winds, according to the 2 p.m. advisory from the National Hurricane Center.

Location: 60 miles south of Cozumel, Mexico

Maximum sustained winds: 40mph

Movement: Stationary

At 2 p.m., the center of Subtropical Storm Alberto was located 60 miles south of Cozumel, Mexico. The storm has been nearly stationary during the past several hours.

A general slow motion toward the north is expected through the weekend, followed by a northwest turn by Monday.

On the forecast track, Alberto is expected to pass near the eastern coast of the Yucatan peninsula tonight, be near the western tip of Cuba Saturday morning, emerge over the southeastern Gulf of Mexico by Saturday night, and approach the north-central Gulf Coast Monday.

Gradual strengthening is forecast for the next 72 hours.

Maximum sustained winds are near 40 mph with higher gusts. Gradual strengthening is forecast for the next 72 hours. Winds of 40 mph extend outward up to 115 miles from the center.

LOCAL IMPACT

Track Subtropical Storm Alberto

Visitors and residents of east Central Florida can expect heavy rain over the Memorial Day weekend. Two to four inches is expected, but there could be up to 7 inches in some locations.

Isolated tornadoes are a possibility.

Impacts will begin Saturday afternoon and last through Monday.

Database: Atlantic hurricanes and tropical storms since 1995

Strong winds are forecast to move through the Space and Treasure coasts as the system travels north through the weekend, dumping rain and bringing the potential for thunderstorms. Early Sunday is now predicted to receive the bulk of rainfall, just as forceful winds are expected to blow in.

In Melbourne, 15 to 20 mph winds are expected through the weekend, with gusts upward of 23 mph Saturday and 26 mph Sunday, according to the National Weather Service in Melbourne. About .4 inches of rain are predicted to fall Sunday morning and into the early afternoon.

Indian River and St. Lucie counties are forecast to see sustained winds speeds between 15 and 20 mph Sunday, though gusts could reach up to 30 mph in Vero Beach and upward of 25 in Fort Pierce, according to meteorologists.

In Martin County, winds are predicted to remain about 20 mph with gusts up to 30 mph Sunday.

More: NOAA forecasters predicting 10-16 named storms for 2018 Atlantic hurricane season

Rain amounts reaching nearly half an inch are expected by 8 a.m. Sunday on the Treasure Coast. The soggy conditions have the potential to last into late next week, according to the Weather Service.

"The main hazard with this system will be locally heavy rainfall with the potential for localized flooding," John Pendergast, meteorologist with the National Weather Service, said in a hazardous weather outlook Friday.

"Dangerous cloud to ground lightning strikes, gusty winds and an isolated tornado will also be a concern as the system moves generally northward over the Gulf of Mexico."

More: It's going to be another busy, above average hurricane season, meteorologists say

HAZARDS AFFECTING LAND

Rainfall: Alberto is expected to produce total rain accumulations of 10 to 15 inches with isolated totals of 25 inches across the northeastern portions of the Yucatan Peninsula and western Cuba.

These rains could produce life-threatening flash floods and mudslides. Rainfall accumulations of 4 to 8 inches with maximum amounts of 12 inches are possible across the Florida Keys and southern and southwestern Florida.

Heavy rain will likely begin to affect the central Gulf Coast region and the southeastern Untied States later this weekend and continue into early next week.

Flooding potential will increase across this region early next week as Alberto is forecast to slow down after it moves inland.

Wind: Tropical storm conditions are possible within the watch area through Saturday.

Surf: Swells generated by Alberto are affecting portions of the coast of eastern Yucatan Peninsula and western Cuba. These swells are likely to cause life-threatening surf and rip current conditions. Hazardous surf conditions are likely to develop along much of the central and eastern U.S. Gulf Coast this weekend.

WATCHES/WARNINGS

A Tropical Storm Watch is in effect for:

Tulum to Cabo Catoche Mexico

Cuban province of Pinar del Rio

A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, in this case within the next 24 hours.

Residents along the central and eastern U.S. Gulf Coast should monitor the progress of Alberto. Tropical storm and storm surge watches could be required for portions of this area later today or tonight.

12:15 p.m.: Gov. Rick Scott meets with officials in the Panhandle and urges all Floridians to monitor Alberto closely and make a plan.

As a precautionary measure, Scott directed the State Emergency Operations Center activate to Level 2.

More: Gov. Scott urges residents to watch Subtropical Storm Alberto closely and make a plan

10:45 a.m.: Subtropical Storm Alberto has formed over the northwestern Caribbean Sea.

Heavy rainfall is expected to affect Florida, western Cuba, the Yucatan Peninsual and the northwest Gulf Coast through the weekend.

Location: 55 miles south of Cozumel, Mexico

Maximum sustained winds: 40 mph

Movement: north-northeast at 6 mph

2018 Atlantic hurricane names The 2018 Atlantic hurricane season begins June 1 and runs through Nov. 30. This year, experts from Colorado State University predict 14 named tropical storms, of which seven will become hurricanes. Both numbers are above the average of 12 and six, respectively.

ALBERTO AT 11 A.M.

#Alberto not just a coastal event. While traveling this weekend into next week, Louisiana to North Carolina including Florida, coast and inland, allow extra time. Slow down to avoid accidents, never drive onto water-covered roads, don’t drive around barricades saying road closed. — Dr. Rick Knabb (@DrRickKnabb) May 25, 2018

It doesn’t matter that it’s not officially #hurricane season yet, and it doesn’t matter that #Alberto is starting off as a subtropical, hybrid storm. The hazards - especially from water - are as real as ever and could be life-threatening if you are not careful, coast and inland. — Dr. Rick Knabb (@DrRickKnabb) May 25, 2018

Watch it: Hurricane forecast model explanation Dr. Ryan Truchelut at WeatherTiger explains hurricane forecast models.

10:03 a.m.: National Hurricane Center will issue an advisory at 11 a.m. on Subtropical Storm Alberto, located over the northwestern Caribbean Sea.

EARLIER STORY

A tropical depression or storm is likely to form Saturday as a low-pressure system over the Caribbean Sea became better defined overnight, according to the 8 a.m. advisory from the National Hurricane Center.

If it continues to strengthen, it could become the first named storm of the season: Alberto.

Meteorologists used satellite images and surface observations to track the system's development overnight, predicting now a 90 percent chance for development in the next two days.

Thunderstorm activity has increased and become better organized.

Heavy rainfall in some areas of western Cuba, much of Florida and the northern Gulf Coast is expected to move through into early next week as the system continues to develop. A subtropical or tropical depression or storm is likely to form by Saturday over the northwestern Caribbean Sea or the southeastern Gulf of Mexico, according to forecasters.

An Air Force Reserve aircraft will investigate the conditions this afternoon.

More: Rainy Memorial Day weekend forecast for Treasure Coast as system moves into Gulf of Mexico

More: Memorial Day ceremonies moved in Vero Beach, Port St. Lucie ahead of stormy weekend

Tropical-storm-force winds and storm surge could make its way to portions of the northern Gulf Coast by late weekend or early next week, while rip current threats increase along the Gulf Coast from Florida to Louisiana over the weekend.

Formation chance through 48 hours: 90 percent.

Formation chance through 5 days: 90 percent.

The next scheduled advisory will be at 2 p.m.

More: Study: Hurricane landfall for East, Gulf coasts probable in 2018

Local conditions

Strong winds are forecast to move through the Space and Treasure coasts as the system travels north through the weekend, dumping rain and bringing the potential for thunderstorms. Early Sunday is now predicted to receive the bulk of rainfall, just as forceful winds are expected to blow in.

More: NOAA forecasters predicting 10-16 named storms for 2018 Atlantic hurricane season

More: It's going to be another busy, above average hurricane season, meteorologists say

In Melbourne, 15 to 20 mph winds are expected through the weekend, with gusts upward of 23 mph Saturday and 26 mph Sunday, according to the National Weather Service in Melbourne. About .4 inches of rain are predicted to fall Sunday morning and into the early afternoon.

Indian River and St. Lucie counties are forecast to see sustained winds speeds between 15 and 20 mph Sunday, though gusts could reach up to 30 mph in Vero Beach and upward of 25 in Fort Pierce, according to meteorologists.

In Martin County, winds are predicted to remain about 20 mph with gusts up to 30 mph Sunday.

Atlantic - System 90L Has High Chance to Become First Atlantic Tropical Depressionhttps://t.co/UrtUNtPHsV pic.twitter.com/JlGAy7XXu9 — NASAHurricane (@NASAHurricane) May 25, 2018

More: It's going to be another busy, above average hurricane season, meteorologists say

Rain amounts reaching nearly half an inch are expected by 8 a.m. Sunday on the Treasure Coast. The soggy conditions have the potential to last into late next week, according to the Weather Service.

Database: Atlantic hurricanes and tropical storms since 1995

"The main hazard with this system will be locally heavy rainfall with the potential for localized flooding," John Pendergast, meteorologist with the National Weather Service, said in a hazardous weather outlook Friday. "Dangerous cloud to ground lightning strikes, gusty winds and an isolated tornado will also be a concern as the system moves generally northward over the Gulf of Mexico."