National Hurricane Center watching stormy area in Atlantic, Florida under heat advisory
"Environmental conditions are marginally conducive, and any development should be slow to occur while the system moves generally west-northwestward at 10 to 15 mph." the National Hurricane Center said in their Tropical Weather Outlook, which currently gives the area a 20% chance of development over the next week.
The NHC is also tracking two tropical waves in the Caribbean.
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The next named storm of the 2025 Atlantic hurricane season will be Dexter.
Historically, the fourth named storm of the Atlantic hurricane season arrives Aug. 15. The last two named storms of the season — Barry and Chantal — developed earlier than normal.
Heat index alert: Weather watches and warnings issued in Florida
Meanwhile the blazing heat continues in the Sunshine State, with an expanding heat dome spreading across the Deep South to the Mississippi and Ohio Valleys, National Weather Service forecasters said.
As of July 21, the entire state is under a heat advisory and roughly two-thirds of Florida from the Panhandle down into Central and Southwest regions may be facing major heat risks.
There's a heat advisory for North Florida and the Panhandle (and parts of southeast Alabama and southern Georgia) running from 11 a.m. ET through 7 p.m. with heat index values up to 112 expected. Advisories for Central, Southwest and South Florida are scheduled for noon through 6 p.m., with heat index values up to 112 possible.
Be careful going outside If you have to, and stay hydrated.
Here's the latest advisory from the National Hurricane Center as of 8 a.m. July 21:
NOAA Hurricane Center tracks tropical disturbance in Atlantic
A tropical wave is located about 900 miles east-southeast of the Lesser Antilles
Showers and thunderstorms associated with a small area of low pressure located about 900 miles east-southeast of the Lesser Antilles have increased some during the past several hours. Environmental conditions are generally favorable for some additional development over the next day or so while the system moves west-northwestward at 10 to 15 mph. By the middle of this week, environmental conditions are forecast to become unfavorable for further development.
Formation chance through 48 hours: Low, 20 percent
Formation chance through 7 days: Low, 20 percent
What do the colored, hatched areas on the NOAA map mean?
The hatched areas on the National Hurricane Center's 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.
Florida weather radar for July 21, 2025
National Weather Service Florida forecast for July 21
: A slight chance of showers and thunderstorms between 1 p.m. and 4 p.m. Sunny, with a high near 93. Heat index values as high as 105. West wind 5 to 10 mph. Chance of precipitation is 20%.
Tallahassee, central Panhandle: A 30% chance of showers and thunderstorms, mainly after 3 p.m. Mostly sunny and hot, with a high near 97. Heat index values as high as 110. Northwest wind around 5 mph.
: Showers and thunderstorms likely, mainly after 3 p.m. Some of the storms could produce heavy rainfall. Mostly sunny and hot, with a high near 96. Heat index values as high as 107. West wind 7 to 9 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
: Showers and thunderstorms likely, mainly after 2 p m. Some of the storms could produce heavy rainfall. Mostly sunny, with a high near 93. Heat index values as high as 108. West wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts between a half and three quarters of an inch possible.
: A slight chance of showers and thunderstorms between 2 p.m. and 4 p.m. Mostly sunny, with a high near 88. Heat index values as high as 100. Southwest wind 5 to 10 mph becoming southeast in the afternoon. Chance of precipitation is 20%.
: A 30% chance of showers and thunderstorms, mainly between 4 p.m and 5 p.m. Sunny, with a high near 92. Heat index values as high as 108. Light and variable wind becoming west northwest 5 to 10 mph in the morning.
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What else is happening in the tropics?
The National Hurricane Center is tracking two tropical waves.
Tropical wave 1: An eastern Atlantic tropical wave has its axis near 30W from 05N to 18N. It is moving westward at 10 to 15 kt. Scattered moderate convection is seen within 120 nm w of the wave axis from 10N to 12N and within 150 nm east of the wave axis from 12N to 14N.
Tropical wave 2: A central Atlantic tropical wave has its axis near 47W from 03N to 17N, part of the area of disturbance mentioned above. Environmental conditions are generally favorable for some additional development of this system over the next day or so while it moves west- northwestward, however, by the middle of this week, environmental conditions are forecast to become unfavorable for further development.
AccuWeather said there's also a potential for tropical development off the central coast of the U.S. July 22-25.
2025 hurricane season so far
An average Atlantic hurricane season has 14 named storms, seven hurricanes, and three major hurricanes.
Here's when this year's named storms have developed, compared to historical averages:
Tropical Storm Andrea: formed June 24. Average start date: June 20
Tropical Storm Barry: formed June 29. Average start date: July 17
Tropical Storm Chantal: formed July 5. Average start date: Aug. 3.
Next up, Dexter: Average state date: Aug. 15, with the average first hurricane forming Aug. 11.
Hurricane names for 2025 season
Here are the names for the 2025 Atlantic hurricane season, along with how to pronounce them:
Andrea (June 24)
Barry (June 29)
Chantal (July 5)
Dexter: DEHK-ster
Erin: AIR-rin
Fernand: fair-NAHN
Gabrielle: ga-bree-ELL
Humberto: oom-BAIR-toh
Imelda: ee-MEHL-dah
Jerry: JEHR-ee
Karen: KAIR-ren
Lorenzo: loh-REN-zoh
Melissa: meh-LIH-suh
Nestor: NES-tor
Olga: OAL-guh
Pablo: PAHB-lo
Rebekah: reh-BEH-kuh
Sebastien: se-BAS-tee-en
Tanya: TAHN-yuh
Van: van
Wendy: WEN-dee
When is the Atlantic hurricane season?
The Atlantic hurricane season runs from June 1 through Nov. 30.
Ninety-seven percent of tropical cyclone activity occurs during this time period, NOAA said.
The Atlantic basin includes the northern Atlantic Ocean, Caribbean Sea and Gulf of America, as the Gulf of Mexico is now known in the U.S. per an order from President Trump. NOAA and the National Hurricane Center are now using Gulf of America on its maps and in its advisories.
When is the peak of hurricane season?
National Hurricane Center map: See what forecasters watching now
Systems currently being monitored by the National Hurricane Center include:
Why does NHC say 'tropical cyclone' on its maps instead of hurricane or tropical storm?
Tropical cyclone is the generic term used by the National Weather Service, NOAA and the National Hurricane Center for any tropical system, even if it's in the tropical Atlantic basin.
To be more precise, a tropical cyclone is a "rotating, organized system of clouds and thunderstorms that originates over tropical or subtropical waters and has closed, low-level circulation," NOAA sadi.
Once maximum sustained winds reach 74 mph, what it is called is determined by where it originated:
: for storms in the North Atlantic, central North Pacific, and eastern North Pacific.
: for storms in the Northwest Pacific.
: for storms in the South Pacific and Indian Ocean.
Interactive map: Hurricanes, tropical storms that have passed near your city
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This article originally appeared on Treasure Coast Newspapers: Hurricane Center increases chances storm development
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