Invest 91L
In early September 2025, cautious optimism surrounded Invest 91L, a weather system that showed potential to develop into a significant tropical cyclone as it moved towards the Eastern Caribbean. The system, initially monitored by the National Hurricane Center, attracted attention because of its possible evolution into Tropical Storm Gabrielle. Initially, various spaghetti models presented a wide array of possible paths, indicating uncertainty yet prompting vigilant observation by meteorologists and residents in the region. Meanwhile, speculation grew about whether another system in the Gulf, humorously dubbed the "Gulf Blob," might transform into Tropical Storm Bertha.
Despite the early hype surrounding Invest 91L, the system ultimately failed to organize into a coherent storm, defying predictions that suggested it could escalate. The weakening of Invest 91L was attributed to unfavorable atmospheric conditions and increased wind shear, which hampered its development. This unexpected fizzling out highlighted the challenges meteorologists face in strengthening storm predictions and underscored the inherent unpredictability of weather systems. Attention likely shifted again to the Gulf, where another storm system began garnering interest as a potential development target.
Tropical Weather Discussion from the National Hurricane Center highlights a gale warning in the Caribbean Sea, particularly north of Colombia, where NE to E winds are expected to reach gale force tonight. Rough seas of 12 to 14 ft are anticipated during peak winds. In the Gulf of America, an upper-level low pressure is causing scattered strong thunderstorms in the eastern Gulf waters, with a medium chance of formation over 7 days. Elsewhere, moderate to fresh winds and slight seas are predominant.
For the Atlantic Ocean, a subtropical ridge is promoting moderate to fresh easterly winds and 4-8 ft seas south of 25N. In the far eastern Atlantic, conditions include moderate winds and 4-7 ft seas north of the monsoon trough, with moderate or weaker winds elsewhere. The subtropical ridge is predicted to weaken as a surface trough forms east of 50W, moving westward by Wednesday. Strong winds are expected to pulse in the evenings near Hispaniola and the Windward Passage.
The National Oceanic and Atmospheric Administration (NOAA) has forecasted an above-normal Atlantic hurricane season for 2025.
Named Storms: 8 to 14
Hurricanes: 3 to 6
Major Hurricanes (Category 3 or higher): 1 to 3
Accumulate Cyclone Energy (ACE): 95% to 180% of the median
Primary Influencing Factor: Developing El Niño conditions expected to suppress Atlantic storm activity
This forecast indicates:
Despite the lower forecast, NOAA emphasizes that it only takes one hurricane making landfall to create a major disaster, and residents in hurricane-prone areas should still prepare as usual for the season.
Hurricane season runs from June 1 through November 30Key: Active Past Future
*Press/click the storm name to view additional detailsDespite fewer total storms than forecasted, the 2025 season produced several extremely intense hurricanes, including three Category 5 systems, making it one of the more powerful Atlantic seasons in recent history.
2020 - 30 named storms, 14 hurricanes
Hurricane Katrina (2005) - $125 billion
Harvey (2017) - $125 billion
Hurricane Patricia (2015) - 215 mph (345 km/h)
Hurricane Allen (1980) - 190 mph (305 km/h)
The Saffir-Simpson Hurricane Wind Scale is a 1 to 5 rating system that classifies hurricanes based on their sustained wind speeds and the potential damage they can cause. It helps communicate the intensity of hurricanes and the likely impacts on structures and environments. The scale does not account for factors like storm surge or rainfall, focusing only on wind speeds.
Watching the Tropics was originally built as a personal storm tracker with only the most important charts for the Atlantic hurricane basin. Numerous sites are available for tracking hurricanes, but Watching the Tropics minimizes extra "noise" and shows only what you need.
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"Watching the tropics" refers to monitoring tropical weather systems, such as tropical depressions, tropical storms, and hurricanes, in regions close to the equator. Meteorologists and weather enthusiasts often use this phrase during hurricane season to indicate that they're keeping an eye on developing weather systems that could potentially strengthen and impact areas like the Caribbean, Gulf of Mexico, and Atlantic Ocean.
Websites, news outlets, or weather services also use "Tropics Watch" to keep the public informed about the latest developments in the tropics, especially during peak hurricane season.
An "invest" refers to an area of disturbed weather that meteorologists are investigating for potential tropical development. The term "invest" is short for "investigation area."
When an area is designated as an invest, it is given a number (between 90 and 99) followed by the letter "L" for systems in the North Atlantic or "E" for systems in the Eastern Pacific. For example, "Invest 91L" would refer to the 91st area of interest in the Atlantic basin for that season.
The designation of an invest allows meteorologists to focus their resources on a specific area, utilize specialized forecasting models, and issue updates as needed.
A tropical depression is a type of tropical cyclone with maximum sustained winds of less than 39 mph (34 knots or 63 km/h).
Key characteristics:
It's the first stage of development in the tropical cyclone classification used by the National Hurricane Center, followed by tropical storm and then hurricane.
