• Thu. Nov 26th, 2020

U.S. could see two tropical systems make landfall on same day

As we enter the heart of hurricane season, twin tropical cyclones are aimed at the U.S. mainland, with both poised to make landfall early next week — possibly on the same day.

This would be the first time two hurricanes occur in the Gulf of Mexico at the same time, which could happen Monday or Tuesday as the storms intensify.

The first of the two storms is Tropical Storm Laura.

As of the 11 a.m. advisory from the National Hurricane Center, Laura had maximum sustained winds of 45 mph, was 210 miles east-southeast of the Northern Leeward Islands and was moving west at 18 mph.

Tropical Storm Warnings were posted for Puerto Rico and the Virgin Islands, and Tropical Storm Watches for the southeastern Bahamas.

Laura was expected to move near or over the Northern Leewards on Friday and Friday night, near or over the Virgin Islands and Puerto Rico on Saturday, and over the Dominican Republic and Haiti on Saturday night. Rain of 3 to 6 inches and in some areas up to 8 inches was possible over Puerto Rico and the Virgin Islands through Sunday, which could cause urban flash flooding and mudslides.

On the current forecast track, the storm will approach South Florida as a strong tropical storm on Monday, then enter the Gulf of Mexico and intensify into a Category 1 hurricane Tuesday with landfall occurring along the Gulf Coast late Tuesday night or early Wednesday morning.

Miami to the Florida Keys to New Orleans needs to be on guard. The most likely arrival time of tropical-storm-force winds for Miami and Florida Keys is Monday morning, Tampa on Monday evening and New Orleans on Tuesday.

The second storm is Tropical Depression 14.

As of the 11 a.m. advisory from the National Hurricane Center on Friday, Tropical Depression 14 had maximum sustained winds of 35 mph, was 165 miles east of the Honduran island of Roatan and was moving northwest at 14 mph. It was expected to strengthen into a tropical storm by Friday night.

A hurricane watch was up from Punta Herrero to Cancun, Mexico. The storm is expected to hit the eastern Yucatan Peninsula over the weekend with 3 to 6 inches of rain, locally up to 10 inches, possible through Sunday.

This system is forecasted to enter the Gulf of Mexico and intensify into a Category 1 hurricane Monday with landfall occurring along the Gulf Coast sometime late Tuesday night or early Wednesday morning.

Brownsville, Texas, to Houston to New Orleans needs to be on guard. The most likely arrival time of tropical-storm-force winds for these locations is Monday evening.

When Tropical Storm Laura was named on Friday morning, it broke the record for the earliest 12th storm on record.

With the tropical depression forecast to become a tropical storm by Saturday, it will be named Marco. and that would break the record for earliest 13th storm on record.

This is on the heels of eight other storms that set the same record this season already: Cristobal, Edouard, Fay, Hanna, Gonzalo, Isaias, Josephine and Kyle.

Given the current forecast, it is feasible there could be three U.S. landfalls in three consecutive days. Laura on Monday on south Florida or the Florida Keys, Tropical Depression 14 (Marco) on Tuesday along the Gulf Coast, and then Laura again on Wednesday along the Gulf Coast.

The record shortest time between U.S. landfalls is 23 hours on Sept. 4 and 5, 1933.

Will the two systems merge? Can they become a “super-hurricane”?

The answer is no. When tropical cyclones interact with each other, the end result is they usually both weaken to a certain extent. This interaction is called the “Fujiwhara Effect,” which describes when tropical cyclones “orbit” or “dance” around each other. Dueling tropical cyclones do not play nice, and their circulations ultimately disrupt each other, promoting a weakening process. Interaction can, however, cause a shift in the track.

Over the next 24 to 48 hours confidence will grow in the track and intensity of both storms. For now, approximately 1,400 miles of U.S. coastline is in one of the cones of uncertainty so all residents along the southeast Florida and Gulf Coasts should have their hurricane plans in place and ready to go.