The system is expected to become tropical storm before landfall Wednesday

• Potential Tropical Cyclone One is expected to become Tropical Storm Alberto.
• Landfall is expected late Wednesday.
• The system is very large, with tropical-storm-force winds extending 290 miles northeast of the center.

Tropical storm warnings have been issued for parts of the Texas coast ahead of Potential Tropical Cyclone One, according to the latest advisory from the National Hurricane Center.

The system is expected to strengthen and is likely to become a tropical storm by Wednesday before approaching the western Gulf Coast late Wednesday. Tropical storm conditions are expected within the warning area by Wednesday.

If it does become a tropical storm, it’ll become the first named storm of the 2024 Atlantic hurricane season, Alberto.

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➤ Excessive rainfall forecast

The National Hurricane Center warned the system is very large: with tropical-storm-force winds extending outward up to 290 miles to the northeast of the center.

Heavy rain is forecast to extend well north of the center of the storm, spreading into portions of central Texas, according to AccuWeather.

Potential Tropical Cyclone One is expected to bring 5 to 10 inches of rain across South Texas and into northeastern Mexico, with up to 15 inches possible, NHC forecasters said.

AccuWeather is predicting over half a foot of rain across parts of the Texas and Louisiana coasts, with up to 30 inches possible in the hardest-hit areas.

“Very warm waters in this area of the Gulf, as well as low wind shear will make this a conducive environment for the tropical rainstorm to strengthen,” said AccuWeather Senior Meteorologist Dan Pydynowski.

Potential Tropical Cyclone One: What you need to know

• Location: 420 miles southeast of Brownsville, Texas
• Maximum sustained winds: 40 mph
• Movement: north at 6 mph
• Pressure: 999 mb
• Next advisory: 8 a.m.

Watches, warnings issued across Florida, Texas, Gulf Coast

For an explanation of what the watches and warnings mean, scroll to the bottom of this story.

• Tropical storm warning: The Texas coast from Port O’Connor southward to the mouth of the Rio Grande.
• Tropical storm watch: The northeastern coast of Mexico south of the mouth of the Rio Grande to Puerto de Altamira.

How strong is Potential Tropical Cyclone One and where is it going?

At 5 a.m. EDT, Potential Tropical Cyclone One was located about 420 miles southeast of Brownsville, Texas, or 350 miles east-southeast of La Pesca, Mexico. Latitude 21.3 North, longitude 93.0 West.

The system is moving toward the north near 6 mph. A gradual turn toward the west-northwest and west is expected is expected Tuesday night and Wednesday, and the system is likely to approach the western Gulf Coast late Wednesday.

Maximum sustained winds remain near 40 mph, with higher gusts. Some increase in strength is likely during the next 36 hours, and the disturbance is forecast to become a tropical storm by Wednesday.

• Formation chance through 48 hours: high, 80 percent.
• Formation chance through 7 days: high, 80 percent.

The disturbance is quite large with tropical-storm-force winds extending outward up to 290 miles to the northeast of the center, the National Hurricane Center said.

Spaghetti models for Potential Tropical Cyclone One

Special note about spaghetti models: Illustrations include an array of forecast tools and models, and not all are created equal. The hurricane center uses only the top four or five highest performing models to help make its forecasts. 

➤ Track Potential Tropical Cyclone One

Key messages from the National Hurricane Center: What you need to know about Potential Tropical Cyclone One

1. Users are reminded not to focus on the exact forecast track of this system. The disturbance is very large with rainfall, coastal flooding, and wind impacts likely to occur far from the center along the coasts of Texas and northeastern Mexico.
2. Rainfall associated with Potential Tropical Cyclone One will impact large regions of Central America, northeastern Mexico and South Texas. This rainfall will likely produce considerable flash and urban flooding along with new and renewed river flooding. Mudslides are also possible in areas of higher terrain across Central America into northeast Mexico.
3. Moderate coastal flooding is likely along much of the Texas Coast beginning Tuesday morning and continuing through midweek.
4. Tropical storm conditions are expected beginning Wednesday over portions of the Texas coast south of Port O’Connor, where a Tropical Storm Warning is in effect, and over portions of northeastern Mexico.

Current forecast: Where is Potential Tropical Cyclone One going and how strong could it get?

• 12 hours: 40 mph
• 24 hours: 45 mph. Would be a tropical storm.
• 36 hours: 50 mph
• 48 hours: 50 mph as it moves inland.
• 60 hours: 35 mph

What impact could Potential Tropical Cyclone One have and what areas could be affected?

• Storm surge: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide:
  • Sargent, Texas, to Sabine Pass, Texas: 2-4 feet
  • Galveston Bay: 2-4 feet
  • Mouth of the Rio Grande, Texas, to Sargent, Texas: 1-3 feet
  • Sabine Pass, Texas, to Vermilion/Cameron Parish Line, Louisiana: 1-3 feet
• The deepest water will occur along the immediate coast near and to the north of the landfall location, where the surge will be accompanied by large and dangerous waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances.
• Rainfall: Potential Tropical Cyclone One is expected to produce rainfall totals of 5 to 10 inches across northeast Mexico into South Texas, with maximum totals of 15 inches possible. This rainfall will likely produce flash and urban flooding along with new and renewed river flooding. Mudslides are also possible in areas of higher terrain across northeast Mexico.
• Wind: Tropical storm conditions are expected within the warning area by Wednesday.

Interactive map: What tropical storms, hurricanes have impacted your area in the past?

What do tropical storm watches, warnings from NHC mean?

What is storm surge? Graphics explain the deadly weather event

Tropical storm warning: A tropical storm warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours.

Tropical storm watch: An announcement that sustained winds of 39 to 73 mph are possible within the specified area within 48 hours in association with a tropical, subtropical, or post-tropical cyclone.