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Tropical disturbance to impact Gulf Coast this week

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July 15, 2025

Swirl of white clouds off the east coast of Florida with bright spots where there is lightning. — This tropical disturbance, currently named Invest 93L, should impact the Gulf Coast states this week. The GOES-East satellite captured this image of the disturbance on July 15, 2025. Image via NOAA/ CIRA.

Tropical disturbance to impact Gulf Coast this week

The National Hurricane Center is monitoring a tropical wave spinning over Florida for possible tropical development. Odds for development have gone up over recent days. As of Tuesday night, the chances for this tropical wave to become at least a tropical depression have increased to 40% within the next two days as well as within the next seven days. The disturbance (now called Invest 93L) is moving to the west. It’s crossing the state of Florida and will emerge into the Gulf as early as Wednesday. From there, development into a tropical depression or storm is possible in the coming days.

Favorable conditions

Invest 93L is moving into the Gulf, where water temperatures are running warmer than average. Tropical cyclones need water temperatures of at least 80° Fahrenheit (27° C) to develop. Current analysis has temperatures in the Gulf ranging from 84° to almost 90° Fahrenheit (29°-32° C)! This is more than enough warm water to fuel a tropical cyclone. In addition to warm water, wind shear is low, which is favorable for tropical development. While there won’t be much time for this tropical wave to organize, if it can stay over the warm waters of the Gulf, it could become a tropical depression. It might even become Tropical Storm Dexter before impacting the northern Gulf Coast, especially Louisiana, later this week.

Rain, with or without a name

Regardless of whether this tropical wave fully develops into a tropical depression or tropical storm, it will bring impacts in the form of heavy rain to the Gulf Coast as early as Wednesday. Up to 4 inches (10 cm) of rain are possible along the coast of Florida, while up to 6 inches (15 cm) are possible for southern Louisiana through the weekend.

There are a few scenarios with this tropical wave and its future. If it stays closer to the coastline while trying to develop, that interaction with land could keep it from developing into a stronger tropical depression or storm. However, if it stays father off shore, away from land interaction, it has the chance to become a tropical depression or Tropical Storm Dexter.

Heavy rain and flooding will still be an issue, no matter what forecast scenario takes place. A flood watch has already been issued for many parishes across southern Louisiana in anticipation of the heavy rain brought by this tropical disturbance.

2 maps of New Orleans area with areas in red, orange, and yellow indicating rainfall totals. — View update. | The weather outlook for the New Orleans area. Image via NOAA/ National Weather Service.

Tropical disturbance vs. tropical depression

In order for the National Hurricane Center to determine if a system has become a tropical depression, the disturbance must have a clear center of circulation. They determine this a number of ways. This includes buoy data, wind direction analyzed by satellites, or through a hurricane hunter flight. Once that center of circulation becomes well defined, experts draw a forecast cone showing the movement of the storm, as well as its forecast strength.

Remember: the forecast cone for a tropical cyclone shows the most likely location of where the center of the storm will track. Impacts can, and often are, felt outside the forecast cone. For more information on how to understand the forecast cone from the National Hurricane Center, click here.

Occasionally, meteorologists issue a forecast cone for something called a Potential Tropical Cyclone. The National Hurricane Center can choose to draw a forecast cone for a system that is not yet a tropical depression (does not have a clear center of circulation) but could bring tropical storm or hurricane impacts to land within the next two days. This is to make sure everyone in the path of the storm is aware of what is headed their way.

The average date for the 4th named storm of the Atlantic hurricane season is August 15. If Dexter does develop in the next few days, it would be almost a month earlier than average. We have yet to experience a hurricane this season, but the average date for the first hurricane is August 11.

Bottom line: A tropical disturbance, currently labeled Invest 93-L, will bring wind and rain to the Gulf Coast states this week. It has the potential to strengthen into Tropical Storm Dexter.

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July 15, 2025

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Rachel Duensing

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About the Author:

Rachel Duensing is a Certified Broadcast Meteorologist by the American Meteorological Society and is currently a meteorologist and climate reporter at CBS17 in Raleigh, North Carolina. Rachel has previously worked in Fort Myers, Florida and Carterville, Illinois. In addition to daily weather, she has covered tornado outbreaks, hurricanes, and extreme heat and cold. Rachel received her Bachelor of Science degree in Meteorology and Digital Media from Valparaiso University in Valparaiso, Indiana. While at Valpo, she was a member of the Valparaiso University Storm Intercept Team, and along with professors and classmates, chased tornadoes and severe weather across the United State's Great Plains and Midwest. Rachel grew up outside Chester, Illinois, a small town in the southern end of the state (nowhere near Chicago!). When she was only 10 years old, Rachel learned about weather in science class, and when those lessons were followed up by a tornado outbreak outside her town, she took it as a sign and has been in love with weather ever since! When not forecasting the weather or reporting on weather and climate, Rachel spends her time volunteering at a local cat shelter and watching hockey with her husband.