As Hurricane Helene soaks Florida, NHC tracking another system near Gulf. Is Texas next?

Helene weakened to a tropical storm Friday, but don't let your guard down just yet — Isaac has strengthened into a hurricane, and another system could develop in the Gulf of Mexico by the end of next week.

The National Hurricane Center is tracking Isaac and three other systems: one in the Caribbean Sea and two in the Atlantic, one of which became Tropical Storm Joyce early Friday.

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Hurricane Helene made landfall on Florida's Big Bend coastline Thursday at 11:10 p.m. as a Category 4 storm, with 140-mph winds, according to the National Hurricane Center .

Isaac, in the central Atlantic, isn't expected to impact the U.S.

Following Helene is an area of low pressure that could form over the western Caribbean Sea next week. Conditions will become more favorable for development as it moves into the Gulf of Mexico toward the end of next week.

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Here's the latest update from the National Hurricane Center as of  8 a.m. Friday, Sept. 27:

Hurricane tracker: See path of Tropical Storm Helene

Spaghetti models for Tropical Storm Helene

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.

Is there another hurricane after Helene? What to know about Hurricane Isaac

• Location : 1,175 miles west of the Azores
• Maximum sustained winds : 75 mph
• Movement : east at 12 mph

At 4 a.m. CDT, the center of Hurricane Isaac was located near latitude 37.0 North, longitude 48.5 West.

Isaac is moving toward the east near 12 mph, and this motion with a gradual turn to the east-northeast is expected over the next several days.

Maximum sustained winds are near 75 mph, with higher gusts.

Additional strengthening is expected during the next day or so, followed by gradual weakening by the end of this weekend. Hurricane-force winds extend outward up to 15 miles from the center and tropical-storm-force winds extend outward up to 70 miles.

Spaghetti models for Hurricane Isaac

NHC tracking 3 other systems in the Atlantic, including Tropical Storm Joyce. Will any impact Texas?

Tropical Storm Joyce, Eastern and Central Tropical Atlantic: Showers and thunderstorms associated with an area of low pressure located midway in between the Cabo Verde Islands and the Lesser Antilles continues to become better organized.

This disturbance is already producing gale-force winds. Environmental conditions are conducive for further development and a tropical depression or storm could form today while the system moves generally westward towest-northwestward at 10 to 15 mph.

The system is then forecast to slow down and turn north-northwestward by this weekend.

• Formation chance through 48 hours : High, 90 percent.
• Formation chance through 7 days : High, 90 percent.

Western Caribbean: An area of low pressure could form over the western Caribbean Sea by the middle of next week.

Environmental conditions are expected to be conducive for slow development thereafter while the system moves generally northwestward, potentially entering the Gulf of Mexico by the end of next week.

• Formation chance through 48 hours : Low, near 0 percent.
• Formation chance through 7 days : Low, 30 percent.

Eastern tropical Atlantic: An area of low pressure could form over the eastern tropical Atlantic by the early to middle part of next week.

Environmental conditions are expected to be conducive for slow development thereafter while the system moves generally northwestward at 10 to 15 mph.

• Formation chance through 48 hours : Low, near 0 percent.
• Formation chance through 7 days : Low, 20 percent.

What do the colored areas on the NOAA map mean?

The hatched areas on a tropical outlook map indicate "areas where a tropical cyclone — which could be a tropical depression, tropical storm or hurricane — could develop," said National Hurricane Center Deputy Director Jamie Rhome.

The colors make it visibly clear how likely a system could develop with yellow being low, orange medium and red high.

The National Hurricane Center generally doesn't issue tropical advisories until there is a named storm, but there is an exception.

"If a system is near land and there is potential for development, the National Hurricane Center won't wait before it issues advisories, even if the system hasn't become an actual storm. This gives residents time to prepare," Rhome said.

It's too early at this time to determine if there will be any impact to Texas or the U.S. from the other disturbances out there.

Forecasters urge all residents to continue monitoring the tropics and to always be prepared. That advice is particularly important for what is expected to be a very active hurricane season.

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— USA TODAY reporter Cheryl McCloud contributed to this report.

This article originally appeared on Austin American-Statesman: As Hurricane Helene soaks Florida, NHC tracking another system near Gulf. Is Texas next?